Study of a QCW Light-emitting-diode (LED)-pumped Solid-state Laser
|
|
- Darren Dickerson
- 5 years ago
- Views:
Transcription
1 Journal of the Korean Physical Society, Vol. 59, No. 5, November 2011, pp Study of a QCW Light-emitting-diode (LED)-pumped Solid-state Laser Kangin Lee, Sangyoon Bae, Jin Seog Gwag, Jin Hyuk Kwon and Jonghoon Yi Department of Physics, Yeungnam University, Gyeungsan , Korea (Received 31 December 2010, in final form 8 September 2011) The lasing of solid-state lasers pumped by light emitting diodes (LEDs) was studied to replace the quasi-continuous-wave (QCW) laser diode in pulse laser pumping. The investigated solid-state gain media included Nd-doped solid-state materials (Nd:YAG, Nd:glass, Nd/Cr:YAG), Ti:sapphire, and solid dye. The gain medium was surrounded by arrays of LEDs very closely. The distribution of the LED radiation absorbed in the gain medium was calculated by using non-sequential ray tracing software. The calculated data transferred to the cavity analysis software and the lasing characteristics were simulated. The calculated results for the absorbed LED distribution and the absorption efficiency in the Nd:YAG rod were compared to experimentally measured fluorescence profile and the absorption efficiency and were found to be accurate within an error of 11%. Among the investigated gain media, Nd/Cr:YAG showed the lowest lasing threshold. We also found that the use of reflector in the pumping chamber could lower the lasing threshold of Nd:YAG to half the lasing threshold without the reflector. PACS numbers: Jb, Rz, Hj Keywords: Light-emitting-diode, LED, Solid-state laser DOI: /jkps I. INTRODUCTION Solid-state lasers have been intensively developed over the past several decades for their wide applications in industry and the military [1 3]. Solid-state lasers pumped by arc lamps are rapidly being replaced by diode-pumped solid-state lasers (DPSSLs). Ti:sapphire lasers and solid dye lasers have also recently been pumped by DPSS green lasers, instead of Ar + ion lasers. Still, most solidstate lasers are pumped by CW diode lasers because quasi-continuous-wave (QCW) laser diodes are very expensive as replacement for flash lamps. Thus, flash-lamppumped solid-state lasers account for a large portion of the high-energy, low-repetition-rate pulse laser market even though they generate a large amount of heat and have short lifetimes. About 40 years ago, the light-emitting diode (LED) was suggested as a pump source for solid-state lasers [4 10]. During early development, the LED had a poor electricity-to-light conversion efficiency, and the output power was very low. Reinberg et al. cooled the LED and the gain material to an extremely low temperature of 77 K to improve the conversion efficiency and the lifetime of the LED [4]. To overcome low absorption efficiency, a Nd:YAG single crystal fiber was used as a gain medium [6,7]. Farmer and Kiang used a gold reflector to concentrate highly diverging LED light to the Nd:YAG rod jhyi@yu.ac.kr [8]. Due to the low output power of the LED, there have been rare reports on LED-pumped lasers since several early developments. The concept of pumping using a semi-conductor-based light source with DPSSL has succeeded. Recently, LEDs, which have low cost and high output power, have developed rapidly for display and illumination applications, and their applications in laser pumping are gaining attention [11 16]. Yang et al. pumped a polymer waveguide by using an InGaN blue LED [13]. They used 10 times higher peak current compared with the normal CW driving current of a LED to get enough pump intensity for lasing. The high cost of diode lasers hinders wide application of DPSSLs. Further, diode lasers are easily damaged by humidity, static electricity, and dust. Pumping using LEDs has merits not only in cost but also in many practical aspects. LEDs are designed to resist static discharge. The emitter is encapsulated by a molded lens, isolating dust and humidity. A broad range of LED spectra allows direct pumping of a tunable gain material such as Ti:sapphire, Alexandrite, or solid dye. As CW laser diodes have different emitter designs, compared with QCW diode lasers, to manage generated heat, they can be operated only in the CW mode. In the case of LED pumping, a laser can be operated in CW, as well as QCW, modes with the same LED source. Even with traditional pump sources such as flash-lamps or arclamps, operation in both modes with the same lamp is impractical. In this work, we investigate the performance of a LED
2 Journal of the Korean Physical Society, Vol. 59, No. 5, November 2011 Fig. 1. (Color online) Structure of the investigated LEDpumped solid-state laser. pumped solid-state laser that uses a very simple pumping chamber structure similar to that of the laser side pumped by diode lasers. When a QCW current is applied to the LED, the peak output power from LED can be increased to several times higher than the CW output power even with the same LED. In previous studies [4 10], special LED chips with spectra matched with the absorption bands of the gain media were especially fabricated for pumping. In this work, we use commercial LEDs with dome lenses on chips that have been developed for illumination applications, and are easily affordable. Calculation by ray tracing software enabled us to calculate the LED energy absorbed in the gain media. The calculated result was transferred to cavity analysis software for the simulation of LED-pumped laseroutput characteristics [17,18]. The investigated gain media in the calculation included Nd:YAG, Nd:glass, Nd/Cr:YAG, solid dye, and Ti:sapphire. From the calculation, we could estimate the minimum requirement for the LED pump power to get lasing and the slope efficiency for each gain medium. To test the accuracy of the simulation, we calculated the distribution of the absorbed energy over a cross-section of the rod and compared the result with the experimentally measured fluorescence profile of a LED-pumped Nd:YAG laser. II. DESIGN AND SIMULATION The gain material was pumped by emission from the LED directly sent to the gain media, as illustrated in Fig. 1. Commercially available high-power white LEDs (S42180, Seoul Semiconductor) and blue LEDs (B42180, Seoul Semiconductor) were used as pumping sources, and they were mounted very close to the gain media. A set of 10 LEDs was mounted linearly on a copper square bar. Four assembled bars surrounded a cylindrical, rodshaped gain medium symmetrically. The gap between the surface of the LED and the laser rod was 1 mm. The gap distance was decided by considering the divergence angle of the LED. The size of each gain medium was 4 mm in diameter and 100 mm in length. From the calculation, we found that about 79.7% of the beam emitted Fig. 2. Spectra of (a) the white LED and (b) the blue LED used in the experiment and the calculation. from LED reached the gain medium s surface directly. To estimate the accuracy of the calculation, we measured fluorescence profile from the rod cross-section and compared it with the calculated distribution. To reflect the actual experimental conditions in the simulation, we measured the output power and the spectrum of the light emitted from each LED by using an integrating sphere and spectrometer (SMS-500, Sphere optics). The measured output power for each white LED was 0.31 W, and that for blue LED was 0.46 W. Although the measured electricity-to-light conversion efficiencies were 7.6% and 11.4%, respectively, for the white and the blue LEDs used here, higher efficiencies up to 50% are expected in the near future. The measured spectra of the LEDs are shown in Figs. 2(a) and (b). For the white LED, part of the blue light with a wavelength of 461 nm was converted to yellow light by the phosphor. Unconverted blue light was mixed with yellow light, giving white light. The spectrum of the white LED had a full width at half maximum (FWHM) of nm. For the blue LED, the spectrum had a FWHM of 25.9 nm, which was still very broad compared with the widths of most absorption lines of Nd:YAG as shown in Fig. 3(a). The intensity of the beam, I(z), after propagating a distance z in the gain medium is given as [19] I(z) = λ2 λ 1 f e (λ) exp( α(λ)z)dλ, (1)
3 Study of a QCW Light-emitting-diode (LED)-pumped Solid-state Laser Kangin Lee et al Table 1. Properties of the laser gain media used in the calculations. Gain Medium Nd:YAG Solid dye Nd:glass Ti:sapphire Nd/Cr:YAG Dopant 1.0 at.% 0.8 milli-mol/l ion/cm 3 ND 1.0 mol% 0.1 wt.% concentration Cr 3.0 mol% Emission cross-section (cm 2 ) (1064 nm) (580 nm) (1064 nm) (795 nm) (1064 nm) Peak absorption coefficient (cm 1 ) (589 nm) (490 nm) (590 nm) (480 nm) (460 nm) Ref , , 26 Table 2. Calculated ratio of the LED beam absorbed by the gain media to the emitted LED beam for the blue and the white LED pump beams. Gain Medium Nd:YAG Solid dye Nd:glass Ti:sapphire Nd/Cr:YAG Absorption efficieny for white LED pumping (%) Absorption efficiency for blue LED pumping (%) Fig. 3. Measured absorption coefficients of (a) Nd:YAG as a function of wavelength. (b) LED spectrum before (thick solid line) and after (thin solid line) transmitting through Nd:YAG. where λ 1 and λ 2 are the lower and the upper limits, respectively, of the emission spectrum f e (λ) of the LED; α(λ) is wavelength-dependent absorption coefficient of the gain medium. The calculation by ray tracing (ZEMAX) considered the measured emission spectra of LEDs by importing the relative strengths of the emitted light intensities at 24 equally spaced, different wavelengths within the emission bandwidth in the input data field [17]. In a similar way, wavelength-dependent absorption coefficient data were imported in the calculation reflecting the absorption spectrum of each gain media. The radiant intensity of the LED showed a Gaussian profile with a FWHM of 125, giving the maximum output in the normal direction. The angular distribution of radiation from the LED was also considered in the calculation. The gain media considered in the calculation are as follows: 1.0-at.% Nd-doped YAG, 0.8 milli-mol/l Rh- 6G-doped PMMA solid dye, glass substrates doped with Nd 3+ ions with a density of ion/cm 3, YAG with a Nd 3+ density of 1.0 mol% and a Cr 3+ density of 3.0 mol% (Nd/Cr:YAG), and a 0.1-wt.% Ti 3+ -ion-doped sapphire crystal. The optical and the physical properties of solid dye in Refs. 20 to 22 were used in the calculation. For the absorption coefficients of Nd:glass and Ti:sapphire, the data reported in Refs. 23 and 24 were used. For Nd/Cr:YAG, data reported in Refs. 25 and 26 were used. The stimulated emission cross-sections at each lasing wavelength and related data for calculations are summarized in Table 1. After the wavelength-dependent absorption coefficient α(λ) and the emission spectra, f e (λ), of the LEDs had been obtained, the absorbed LED pump power was calculated. Table 2 shows the ratio of LED power absorbed by the gain media to the emitted LED power obtained from the calculation. For Nd:YAG, solid dye, Nd:glass, Ti:sapphire, and Nd/Cr:YAG, the cal-
4 Journal of the Korean Physical Society, Vol. 59, No. 5, November 2011 Fig. 4. Laser output energies as functions of the output coupler reflectivity for (a) the white LED pumping case and (b) the blue LED pumping case. The maximum output energy from the LEDs is 192 mj. culated results showed absorption efficiencies of 6.2%, 24.3%, 8.4%, 4.2%, and 43.4%, respectively, in case of white LED pumping. For the case of blue LED pumping, the absorption efficiencies were to 4.5%, 53.8%, 4.7%, 7.6%, and 52.7% respectively. Solid dye showed the highest absorption efficiency of 53.8% as the emission band of the blue LED was located close to the peak absorption wavelength of the solid dye. If green LEDs were used, Ti:sapphire also had a higher efficiency. The result shows that a reflector is required in the pumping chamber when a gain medium with a low absorption efficiency is used, to enhance the absorption efficiency through repeated transmission through the gain medium. Figure 3(a) shows the measured absorption coefficients versus wavelength for a 1.0-at.% Nd-doped YAG crystal (Casix) obtained using a spectrometer (Varian Inc., Cary 500), and Fig. 3(b) shows the measured spectra of white LED before and after transmitting through the Nd:YAG crystal. From the measured spectra, we found that 7.4% of the power emitted from the white LED was absorbed by the Nd:YAG rod. This result was in good agreement with the calculated value of 6.2% with an error of 11%. In the calculation, the LEDs were assumed to have a maximum total pump energy of 192 mj (4.8 mj 40 ea.). The temporal duration of the pump pulse was assumed to be 200 µs considering the fluorescence lifetime of Nd:YAG. As the fluorescence lifetimes of Ti:sapphire (3.2 µs) and solid dye ( 10 ns) are much shorter than the pump duration, the QCW pumpings of Ti:sapphire and solid dye are similar to CW pumping with a LED of 960-W power for 200 µs. In the case of Nd/Cr:YAG, the fluorescence lifetime is near 600 µs, much longer than Nd:YAG. In this case, a pump pulse with a 200-µs temporal duration was applied for comparison of the lasing performance. The calculated data for the distribution of the LED energy absorbed by the gain media were imported to LASCAD [18]. From a calculation using LAS- CAD, the thermal effects in the gain media, as well as laser power, could be obtained. In the calculation, the cavity length was 104 mm, and cavity mirrors had flat surfaces except for the case of solid dye. The thermal lens of most gain media was very long, ranging from 200 m to 600 m. Due to strong absorption at the rod surface, the solid dye rod showed a thermal lens with a negative focal length of 600 m. When the solid dye was pumped by white LEDs or blue LEDs, the radius of curvature of the end mirror for the stable resonator condition was 100 m. Figures 4(a) and (b) show the calculated output energies for both cases of white LED pumping and blue LED pumping as functions of the output coupler reflectivity. The cavity loss was assumed to be 0.02 in the calculation. The output coupler reflectivities for maximum output energy when blue LEDs were used were 96% for Nd:YAG, 97% for solid dye, and 93% for Nd/Cr:YAG. However, lasing was not observed for Ti:sapphire and Nd:glass at this pump energy. Figure 5 shows the calculated output energies of white LED pumped lasers and blue LED pumped lasers as functions of the LED pump energy for each gain medium. The output energies of the white LED required to the reach lasing thresholds of Nd:YAG, solid dye, Nd:glass and Nd/Cr:YAG were 45.3 mj, 26.0 mj, 181 mj, and 5.1 mj, respectively. On the other hand, the lasing thresholds of Nd:YAG, solid dye and Nd/Cr:YAG were 54.2 mj, 18.3 mj, and 4.8 mj when a blue LED was used for pumping. Although Nd:glass has an absorption peak near 600 nm and its absorption spectrum is broad, the lasing threshold is higher than that of Nd:YAG because the emission cross-section is 10 times smaller than that of Nd:YAG [23,24]. Ti:sapphire showed a lower absorption efficiency of 4.2% because the LED spectrum is located on the wing of the wide absorption band. Due to the low absorption coefficient, a much higher pump LED power is required compared with the case of Nd:YAG laser. Even though blue LED pumping is more favorable for the Ti:sapphire laser, the absorption efficiency is at 7.6%, and the required pump energy for lasing threshold is 383 mj. The slope efficiencies of the white LED pumped Nd:YAG and blue LED pumped Nd:YAG were 1.5% and 1.1%, respectively. Considering 40 LEDs participate in pumping, each white LED should have an output en-
5 Study of a QCW Light-emitting-diode (LED)-pumped Solid-state Laser Kangin Lee et al Fig. 7. (Color online) Photo of a blue-led-pumped Nd:YAG laser. Fig. 5. Laser output energies as functions of (a) the white LED pump energy and (b) the blue LED pump energy. Fig. 6. Laser output energy as a function of the white LED pump energy when a reflector is enclosed in the gain medium. ergy of 1.1 mj, also, each blue LED should have an output energy of 1.4 mj to reach the lasing threshold for Nd:YAG. For the case of a LED-pumped solid dye laser, each white LED should have an output energy of 0.65 mj, and each blue LED should have an output energy of 0.46 mj to reach the lasing thresholds. The pump energies per LED to reach the lasing threshold were the lowest for Nd/Cr:YAG, and they were 0.13 mj for the white LED and 0.12 mj for the blue LED. The blue LED pumped solid dye showed the highest slope efficiency of Fig. 8. (Color online) Distributions of the absorbed blue LED beam over a cross-section of the Nd:YAG rod obtained by (a) measurement and (b) calculation. Arrows indicate the direction of the pump LED beam. 23.6% and an optical-to-optical energy conversion efficiency of 16.8%. The lower optical-to-optical efficiency for Nd:YAG is caused by its low absorption efficiency. A reflector enclosing the gain medium can enhance the absorption efficiency greatly. According to the calculation, assuming a 99% reflector of 8 mm in diameter is placed with its symmetry axis overlapping the Nd:YAG, the absorption efficiency increases to 13.5% from 6.2% for the while LED pumping case. Also, the lasing threshold was lowered to 26.7 mj, and the slope efficiency was increased to 3.2%, as shown in Fig. 6. Compared with the results shown in Fig. 5(a), the slope efficiencies of gain media with lower absorption efficiencies are notably enhanced while Nd/Cr:YAG shows a slight enhancement. To see the accuracy of the calculated results for the performance of LED-pumped solid-state lasers, we fabricated a pumping chamber with a geometry similar to the one shown in Fig. 1. Figure 7 shows a photo of the fabricated pumping chamber. Each blue LED had a maximum output energy of 0.1 mj. The LEDs were mounted on four copper bars. The surface of each copper bar was coated with an electrical insulator to isolate it from the parallel metal wires connecting the electrodes of the LEDs. Both ends of the copper bar were tightly fixed to a housing made of brass. The base plate of the housing was cooled by water at a temperature of 20 C. Both ends of the Nd:YAG rod were wrapped with indium foil and then secured at the hole of the housing for
6 Journal of the Korean Physical Society, Vol. 59, No. 5, November 2011 about 1/5 the required energy for the lasing threshold of Nd:YAG. If a pumping chamber with reflector is used, lasing can be achieved when the energy of the tested LED is increased to only two times higher. Even without the reflector, when the Nd:YAG is replaced by Nd/Cr:YAG, an output energy of 1.4 mj/pulse is expected when a pump energy of 10.8 mj/pulse (0.27 mj 40) is emitted from the 40 blue LEDs tested in this work. III. CONCLUSION Fig. 9. (Color online) (a) Blue LED output for various the peak driving currents and (b) the total emitted LED energy as a function of the peak current for several different QCW current pulses. conduction cooling. Fluorescence from the Nd:YAG rod was observed while the blue LEDs were turned on. Figure 8(a) shows a fluorescence image of the rod taken by using a CCD camera and image capture program. Figure 8(b) is cross-sectional view of calculated distribution of LED beam absorbed by the Nd:YAG rod, and both results are quite similar, implying a high accuracy for the calculation. When QCW current pulses were sent to the LEDs, the peak output power from the LEDs could be increased to several times higher than the peak power from the CW LEDs. Figure 9(a) shows the emitted blue LED output as a function of the peak current for a repetition rates of 25 Hz and a current duration of 200 µs. The peak current of the QCW pulse was increased to 10 times the normal CW current for the LEDs. When the applied peak current was increased to larger than 10 A, the LEDs were damaged. Figure 9(b) shows the measured pump pulse energy from the LED as a function of the applied peak current. The result shows that the pump pulse energy from a single LED was 0.27 mj, 2.9 times higher than the energy from a cw LED during 200 µs. Although the tested blue LED showed less energy than the LED in Ref. 13, the results demonstrated that QCW pumping could be an effective means of increasing the peak pump power. The pump energy of the tested blue LED was Several solid-state lasers pumped by QCW LEDs were investigated. The accuracy of the calculation was confirmed by comparing the measured absorption efficiency and absorbed power distribution over the laser rod crosssection with the calculated results. In the calculation, several gain media (4-mm diameter and 100-mm length), such as Nd:YAG, Nd:glass, solid dye, Ti:sapphire, and Nd/Cr:YAG, were investigated for white LED and blue LED pumping. From the calculation, not only the absorption efficiency of pump LED beam in each gain medium but also the lasing threshold and the slope efficiency of each laser could be estimated. Among the tested gain media, Nd/Cr:YAG showed the lowest lasing threshold of 4.8 mj/pulse, and solid dye showed the highest slope efficiency of 23.6%. To get lasing with the test setup for the fluorescence measurement, we had to use Nd/Cr:YAG. When Nd:YAG with a 1.0-at% Nd concentration was used, a 5 times higher power blue LED was needed for lasing. A pumping chamber with a reflector could reduce the blue LED pump energy for lasing of Nd:YAG to 22.3 mj/pulse from 54.1 mj/pulse. The results demonstrate that lasing of LED-pumped Nd:YAG is accessible with a simple direct pumping configuration when a pumping chamber with reflector is used. Further, when Cr/Nd:YAG is used, an optical-to-optical efficiency of 13% can be obtained by using the tested blue LEDs even without a reflector. ACKNOWLEDGMENTS This research was supported by Yeungnam University Research Grants in REFERENCES [1] A. Minassian, B. Thompson and M. J. Damzen, Appl. Phys. B 76, 341 (2003). [2] X. Ya, Q. Liu, M. Gong, X. Fu and D. Wang, Appl. Phys. B 95, 323 (2009). [3] Y. Sun, H. Zhang, Q. Liu, L. Huang, Y. Wang and M. Gong, Laser Phys. Lett. 7, 722 (2010).
7 Study of a QCW Light-emitting-diode (LED)-pumped Solid-state Laser Kangin Lee et al [4] A. R. Reinberg, L. A. Riseberg, R. M. Brown, R. W. Wacker and W. C. Holton, Appl. Phys. Lett. 19, 11 (1971). [5] M. Saruwatari, T. Kimura, T. Yamada and J. Nakano, Appl. Phys. Lett. 27, 682 (1975). [6] J. Stone, C. A. Burrus, A. G. Dentai and B. I. Miller, Appl. Phys. Lett. 29, 37 (1976). [7] J. Stone and C. A. Burrus, Fiber Integr. Opt. 2, 19 (1979). [8] G. I. Farmer and Y. C Kiang, J. Appl. Phys. 45, 1356 (1974). [9] J. P. Budin, M. Neubauer and M. Rondot, Appl. Phys. Lett. 33, 309 (1978). [10] F. W. Ostermayer, Jr., IEEE J. Quantum Electron. QE- 13, 1 (1977). [11] J. M. Lupton, Nature 453, 459 (2008). [12] G. A Turnbull, Y. Yang, P. Shaw, A. Ruseckas and I. D. W. Samuel, in Proc. SPIE (San Diego, California, USA, August 10-12, 2008), Vol [13] Y. Yang, G. A Turnbull and I. D. W. Samuel, Appl. Phys. Lett. 92, (2008). [14] F. J. Duarte, US Patent US2005/ , [15] N. Luo, S.-H. Zhu, S. Lu and F. Zhou, US Patent US2005/ , [16] R. Schwps, US Patent US H2161 H, [17] [18] [19] W. Demtroeder, Laser Spectroscopy (Springer-Verlag, Berlin, 1981). [20] A. Kurian, N. A. George, B. Paul, V. P. N. Nampoori and C. P. F. Vallabhan, Laser Chem. 20, 99 (2002). [21] A. Penzkofer and W. Baumler, Opt. Quantum Electron. 23, 727 (1999). [22] A. K. Ray, S. Kumar, N. V. Mayekar, S. Shinha, S. Kundu, S. Chattopadhyay and K. Dasgupta, Appl. Opt. 44, 7814 (2005). [23] W. F. Frupke and L. L. Shase, Opt. Quantum Electron. 22, S1 (1990). [24] W. Koechner, Solid State Laser Engineering (Springer, New York, 1999). [25] T. Saiki, S. Motokoshi, K. Imasaki, K. Fujioka, H. Fujita, M. Nakatsuka, Y. Izawa and C. Yamanaka, Jpn. J. Appl. Phys. 47, 7896 (2008). [26] T. Saiki, K. Imasaki, S. Motokoshi, C. Yamanaka and Y. Izawa, Opt. Commun. 268, 155 (2006).
New Concept of DPSSL
New Concept of DPSSL - Tuning laser parameters by controlling temperature - Junji Kawanaka Contributors ILS/UEC Tokyo S. Tokita, T. Norimatsu, N. Miyanaga, Y. Izawa H. Nishioka, K. Ueda M. Fujita Institute
More informationSintec Optronics Pte Ltd
Sintec Optronics Pte Ltd High-efficiency Nd:YVO 4 laser end-pumped with a diode laser bar Yihong Chen a, Zhengjun Xiong a, Gnian Cher Lim a, Hong Yu Zheng a, Xiaoyuan Peng b a Gintic Institute of Manufacturing
More informationIN RECENT YEARS, Cr -doped crystals have attracted a
2286 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 33, NO. 12, DECEMBER 1997 Optimization of Cr -Doped Saturable-Absorber -Switched Lasers Xingyu Zhang, Shengzhi Zhao, Qingpu Wang, Qidi Zhang, Lianke Sun,
More informationA microring multimode laser using hollow polymer optical fibre
PRAMANA c Indian Academy of Sciences Vol. 75, No. 5 journal of November 2010 physics pp. 923 927 A microring multimode laser using hollow polymer optical fibre M KAILASNATH, V P N NAMPOORI and P RADHAKRISHNAN
More informationA tunable corner-pumped Nd:YAG/YAG composite slab CW laser
Chin. Phys. B Vol. 21, No. 1 (212) 1428 A tunable corner-pumped Nd:YAG/YAG composite slab CW laser Liu Huan( 刘欢 ) and Gong Ma-Li( 巩马理 ) State Key Laboratory of Tribology, Center for Photonics and Electronics,
More informationShift and broadening of emission lines in Nd 3+ :YAG laser crystal influenced by input energy
PRAMANA c Indian Academy of Sciences Vol. 86, No. 6 journal of June 16 physics pp. 1307 1312 Shift and broadening of emission lines in Nd 3+ :YAG laser crystal influenced by input energy SEYED EBRAHIM
More informationHigh Power Continuous Wave Nd:KGW Laser With Low Quantum Defect Diode Pumping
High Power Continuous Wave Nd:KGW Laser With Low Quantum Defect Diode Pumping By Rubel Chandra Talukder A Thesis submitted to the Faculty of Graduate Studies of The University of Manitoba In partial fulfillment
More informationThe FEA Code of LASCAD
The FEA Code of LASCAD Konrad Altmann LAS-CAD GmbH Heat removal and thermal lensing constitute key problems for the design of laser cavities for solid-state lasers (SSL, DPSSL etc.). To compute thermal
More informationThe Generation of Ultrashort Laser Pulses
The Generation of Ultrashort Laser Pulses The importance of bandwidth More than just a light bulb Two, three, and four levels rate equations Gain and saturation But first: the progress has been amazing!
More informationAr and Kr ion lasers
Types of Lasers Ar and Kr ion lasers Nd:YAG and Nd:YLF lasers CO 2 lasers Excimer lasers Dye lasers Transition metal lasers Optical parametric amplification Ar and Kr ion lasers Noble gas ions are created
More informationComparison of different composite Nd:YAG rods thermal properties under diode pumping
Comparison of different composite Nd:YAG rods thermal properties under diode pumping Jan Šulc a, Helena Jelínková a, Václav Kubeček a Karel Nejezchleb b, Karel Blažek b a Czech Technical University, Faculty
More informationWhat do we study and do?
What do we study and do? Light comes from electrons transitioning from higher energy to lower energy levels. Wave-particle nature of light Wave nature: refraction, diffraction, interference (labs) Particle
More informationUltra-narrow-band tunable laserline notch filter
Appl Phys B (2009) 95: 597 601 DOI 10.1007/s00340-009-3447-6 Ultra-narrow-band tunable laserline notch filter C. Moser F. Havermeyer Received: 5 December 2008 / Revised version: 2 February 2009 / Published
More informationModern optics Lasers
Chapter 13 Phys 322 Lecture 36 Modern optics Lasers Reminder: Please complete the online course evaluation Last lecture: Review discussion (no quiz) LASER = Light Amplification by Stimulated Emission of
More informationMaterialwissenschaft und Nanotechnologie. Introduction to Lasers
Materialwissenschaft und Nanotechnologie Introduction to Lasers Dr. Andrés Lasagni Lehrstuhl für Funktionswerkstoffe Sommersemester 007 1-Introduction to LASER Contents: Light sources LASER definition
More informationComputer Modelling and Numerical Simulation of the Solid State Diode Pumped Nd 3+ :YAG Laser with Intracavity Saturable Absorber
Copyright 2009 by YASHKIR CONSULTING LTD Computer Modelling and Numerical Simulation of the Solid State Diode Pumped Nd 3+ :YAG Laser with Intracavity Saturable Absorber Yuri Yashkir 1 Introduction The
More informationChemistry Instrumental Analysis Lecture 5. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 5 Light Amplification by Stimulated Emission of Radiation High Intensities Narrow Bandwidths Coherent Outputs Applications CD/DVD Readers Fiber Optics Spectroscopy
More informationMEFT / Quantum Optics and Lasers. Suggested problems Set 4 Gonçalo Figueira, spring 2015
MEFT / Quantum Optics and Lasers Suggested problems Set 4 Gonçalo Figueira, spring 05 Note: some problems are taken or adapted from Fundamentals of Photonics, in which case the corresponding number is
More informationOPTI510R: Photonics. Khanh Kieu College of Optical Sciences, University of Arizona Meinel building R.626
OPTI510R: Photonics Khanh Kieu College of Optical Sciences, University of Arizona kkieu@optics.arizona.edu Meinel building R.626 Announcements HW #5 due today April 11 th class will be at 2PM instead of
More informationResonantly Pumped Er:YAG and Er:YAP Lasers
Resonantly Pumped Er:YAG and Er:YAP Lasers Michal Němec a*, Helena Jelínková a, Jan Šulc a Karel Nejezchleb b, Václav Škoda b a Faculty of Nuclear Sciences and Physical Engineering Czech Technical University
More informationChapter 7: Optical Properties of Solids. Interaction of light with atoms. Insert Fig Allowed and forbidden electronic transitions
Chapter 7: Optical Properties of Solids Interaction of light with atoms Insert Fig. 8.1 Allowed and forbidden electronic transitions 1 Insert Fig. 8.3 or equivalent Ti 3+ absorption: e g t 2g 2 Ruby Laser
More informationEfficient generation of blue light by intracavity frequency doubling of a cw Nd:YAG laser with LBO
Optics & Laser Technology 39 (2007) 1421 1425 www.elsevier.com/locate/optlastec Efficient generation of blue light by intracavity frequency doubling of a cw Nd:YAG laser with LBO Pingxue Li a,, Dehua Li
More informationHigh-power Cryogenic Yb:YAG Lasers and Optical Particle Targeting for EUV Sources *
High-power Cryogenic Yb:YAG Lasers and Optical Particle Targeting for EUV Sources * J.D. Hybl**, T.Y. Fan, W.D. Herzog, T.H. Jeys, D.J.Ripin, and A. Sanchez 2008 International Workshop on EUV Lithography
More informationCHAPTER 7 SUMMARY OF THE PRESENT WORK AND SUGGESTIONS FOR FUTURE WORK
161 CHAPTER 7 SUMMARY OF THE PRESENT WORK AND SUGGESTIONS FOR FUTURE WORK 7.1 SUMMARY OF THE PRESENT WORK Nonlinear optical materials are required in a wide range of important applications, such as optical
More informationHigh-power Cryogenic Yb:YAG Lasers and Optical Particle Targeting for EUV Sources *
High-power Cryogenic Yb:YAG Lasers and Optical Particle Targeting for EUV Sources * J.D. Hybl**, T.Y. Fan, W.D. Herzog, T.H. Jeys, D.J.Ripin, and A. Sanchez EUV Source Workshop 29 May 2009 * This work
More informationLaser-produced extreme ultraviolet (EUV) light source plasma for the next generation lithography application
Laser-produced extreme ultraviolet (EUV) light source plasma for the next generation lithography application EUV light source plasma Tin icrodroplet Main pulse (CO2 laser pulse) Pre-pulse (Nd:YAG laser
More informationDevelopment of a table top TW laser accelerator for medical imaging isotope production
Development of a table top TW laser accelerator for medical imaging isotope production R U I Z, A L E X A N D R O 1 ; L E R A, R O B E R T O 1 ; T O R R E S - P E I R Ó, S A LVA D O R 1 ; B E L L I D O,
More informationTemperature-dependent spectroscopic analysis of F 2 + ** and F 2 + **-like color centers in LiF
Journal of Luminescence 91 (2000) 147 153 Temperature-dependent spectroscopic analysis of F 2 + ** and F 2 + **-like color centers in LiF Neil W. Jenkins a, *, Sergey B. Mirov a, Vladimir V. Fedorov b
More informationSECOND HARMONIC GENERATION IN PERIODICALLY POLED NONLINEAR CRYSTALS WITH 1064 nm GAUSSIAN LASER PULSES
SECOND HARMONIC GENERATION IN PERIODICALLY POLED NONLINEAR CRYSTALS WITH 1064 nm GAUSSIAN LASER PULSES LIVIU NEAGU National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG-36, 077125, Bucharest,
More informationLaser Physics OXFORD UNIVERSITY PRESS SIMON HOOKER COLIN WEBB. and. Department of Physics, University of Oxford
Laser Physics SIMON HOOKER and COLIN WEBB Department of Physics, University of Oxford OXFORD UNIVERSITY PRESS Contents 1 Introduction 1.1 The laser 1.2 Electromagnetic radiation in a closed cavity 1.2.1
More informationHo:YLF pumped HBr laser
Ho:YLF pumped HBr laser L R Botha, 1,2,* C Bollig, 1 M J D Esser, 1 R N Campbell 4, C Jacobs 1,3 and D R Preussler 1 1 National Laser Centre, CSIR, Pretoria, South Africa 2 Laser Research Institute, Department
More informationNeodymium Laser Q-Switched with a Cr 4+ : YAG Crystal: Control over Polarization State by Exterior Weak Resonant Radiation
Laser Physics, Vol., No.,, pp. 46 466. Original Text Copyright by Astro, Ltd. Copyright by MAIK Nauka /Interperiodica (Russia). SOLID STATE LASERS AND NONLINEAR OPTICS Neodymium Laser Q-Switched with a
More informationLASER. Light Amplification by Stimulated Emission of Radiation
LASER Light Amplification by Stimulated Emission of Radiation Energy Level, Definitions The valence band is the highest filled band The conduction band is the next higher empty band The energy gap has
More informationLaboratory 3: Confocal Microscopy Imaging of Single Emitter Fluorescence and Hanbury Brown, and Twiss Setup for Photon Antibunching
Laboratory 3: Confocal Microscopy Imaging of Single Emitter Fluorescence and Hanbury Brown, and Twiss Setup for Photon Antibunching Jonathan Papa 1, * 1 Institute of Optics University of Rochester, Rochester,
More informationStrongly enhanced negative dispersion from thermal lensing or other focusing effects in femtosecond laser cavities
646 J. Opt. Soc. Am. B/ Vol. 17, No. 4/ April 2000 Paschotta et al. Strongly enhanced negative dispersion from thermal lensing or other focusing effects in femtosecond laser cavities R. Paschotta, J. Aus
More informationNanocomposite photonic crystal devices
Nanocomposite photonic crystal devices Xiaoyong Hu, Cuicui Lu, Yulan Fu, Yu Zhu, Yingbo Zhang, Hong Yang, Qihuang Gong Department of Physics, Peking University, Beijing, P. R. China Contents Motivation
More informationNo. 9 Experimental study on the chirped structure of the construct the early time spectra. [14;15] The prevailing account of the chirped struct
Vol 12 No 9, September 2003 cfl 2003 Chin. Phys. Soc. 1009-1963/2003/12(09)/0986-06 Chinese Physics and IOP Publishing Ltd Experimental study on the chirped structure of the white-light continuum generation
More informationSupporting information. Unidirectional Doubly Enhanced MoS 2 Emission via
Supporting information Unidirectional Doubly Enhanced MoS 2 Emission via Photonic Fano Resonances Xingwang Zhang, Shinhyuk Choi, Dake Wang, Carl H. Naylor, A. T. Charlie Johnson, and Ertugrul Cubukcu,,*
More informationRuby crystals and the first laser A spectroscopy experiment
Introduction: In this experiment you will be studying a ruby crystal using spectroscopy. Ruby is made from sapphire (Al 2 O 3 ) which has been doped with chromium ions, Cr(3+). There are three sets of
More informationBlue-green Emitting Semiconductor Disk Lasers with Intra-Cavity Frequency Doubling
Blue-green Emitting Semiconductor Disk Lasers with Intra-Cavity Frequency Doubling Eckart Schiehlen and Michael Riedl Diode-pumped semiconductor disk lasers, also referred to as VECSEL (Vertical External
More informationStudy of Steady and Transient Thermal Behavior of High Power Semiconductor Lasers
Study of Steady and Transient Thermal Behavior of High Power Semiconductor Lasers Zhenbang Yuan a, Jingwei Wang b, Di Wu c, Xu Chen a, Xingsheng Liu b,c a School of Chemical Engineering & Technology of
More informationRichard Miles and Arthur Dogariu. Mechanical and Aerospace Engineering Princeton University, Princeton, NJ 08540, USA
Richard Miles and Arthur Dogariu Mechanical and Aerospace Engineering Princeton University, Princeton, NJ 08540, USA Workshop on Oxygen Plasma Kinetics Sept 20, 2016 Financial support: ONR and MetroLaser
More information(b) Spontaneous emission. Absorption, spontaneous (random photon) emission and stimulated emission.
Lecture 10 Stimulated Emission Devices Lasers Stimulated emission and light amplification Einstein coefficients Optical fiber amplifiers Gas laser and He-Ne Laser The output spectrum of a gas laser Laser
More informationAn alternative method to specify the degree of resonator stability
PRAMANA c Indian Academy of Sciences Vol. 68, No. 4 journal of April 2007 physics pp. 571 580 An alternative method to specify the degree of resonator stability JOGY GEORGE, K RANGANATHAN and T P S NATHAN
More informationSuppression of thermal lensing effects in intra-cavity coherent combining of lasers
Optics Communications 276 (27) 39 44 www.elsevier.com/locate/optcom Suppression of thermal lensing effects in intra-cavity coherent combining of lasers Sharona Sedghani *, Vardit Eckhouse, Asher A. Friesem,
More informationComparison of cw laser performance of Nd:KGW, Nd:YAG, Nd:BEL, and Nd:YVO 4 under laser diode pumping
Appl. Phys. B 67, 11 15 (1998) Applied Physics B Lasers and Optics Springer-Verlag 1998 Comparison of cw laser performance of Nd:KGW, Nd:YAG, Nd:BEL, and Nd:YVO 4 under laser diode pumping A.A. Demidovich
More informationStimulated Emission Devices: LASERS
Stimulated Emission Devices: LASERS 1. Stimulated Emission and Photon Amplification E 2 E 2 E 2 hυ hυ hυ In hυ Out hυ E 1 E 1 E 1 (a) Absorption (b) Spontaneous emission (c) Stimulated emission The Principle
More informationPhys 2310 Fri. Dec. 12, 2014 Today s Topics. Begin Chapter 13: Lasers Reading for Next Time
Phys 2310 Fri. Dec. 12, 2014 Today s Topics Begin Chapter 13: Lasers Reading for Next Time 1 Reading this Week By Fri.: Ch. 13 (13.1, 13.3) Lasers, Holography 2 Homework this Week No Homework this chapter.
More informationEffect of Addition Au Nanoparticles on Emission Spectra of Laser Dye
International Journal of Applied Engineering Research ISSN 973-462 Volume 2, Number 24 (27) pp. 4833-484 Effect of Addition Au Nanoparticles on Emission Spectra of Laser Dye Sara Ali Razzak, Lazem Hassan
More informationSUPPLEMENTARY INFORMATION
Supplementary Information Speckle-free laser imaging using random laser illumination Brandon Redding 1*, Michael A. Choma 2,3*, Hui Cao 1,4* 1 Department of Applied Physics, Yale University, New Haven,
More informationSegmented 1.55um Laser with 400% Differential Quantum Efficiency J. Getty, E. Skogen, L. Coldren, University of California, Santa Barbara, CA.
Segmented 1.55um Laser with 400% Differential Quantum Efficiency J. Getty, E. Skogen, L. Coldren, University of California, Santa Barbara, CA. Abstract: By electrically segmenting, and series-connecting
More informationEngineering Medical Optics BME136/251 Winter 2017
Engineering Medical Optics BME136/251 Winter 2017 Monday/Wednesday 2:00-3:20 p.m. Beckman Laser Institute Library, MSTB 214 (lab) Teaching Assistants (Office hours: Every Tuesday at 2pm outside of the
More informationDesign and construction of a tunable pulsed Ti:sapphire laser
J Theor Appl Phys (2015) 9:99 103 DOI 10.1007/s40094-015-0164-x RESEARCH Design and construction of a tunable pulsed Ti:sapphire laser Omid Panahi Majid Nazeri Seyed Hassan Tavassoli Received: 8 July 2014
More informationLaser. emission W FL
W Laser Laser emission W FL Supplementary Figure 1. Comparison between fluorescence and laser emission spectra. The fluorescence has broad spectrum whereas the laser has very narrow spectrum. W FL and
More informationVisualization of Xe and Sn Atoms Generated from Laser-Produced Plasma for EUV Light Source
3rd International EUVL Symposium NOVEMBER 1-4, 2004 Miyazaki, Japan Visualization of Xe and Sn Atoms Generated from Laser-Produced Plasma for EUV Light Source H. Tanaka, A. Matsumoto, K. Akinaga, A. Takahashi
More informationHigh-power terahertz radiation from surface-emitted THz-wave parametric oscillator
High-power terahertz radiation from surface-emitted THz-wave parametric oscillator Li Zhong-Yang( ) a)b), Yao Jian-Quan( ) a)b), Xu De-Gang( ) a)b), Zhong Kai( ) a)b), Wang Jing-Li( ) a)b), and Bing Pi-Bin(
More informationMorphology-dependent resonance induced by two-photon excitation in a micro-sphere trapped by a femtosecond pulsed laser
Morphology-dependent resonance induced by two-photon excitation in a micro-sphere trapped by a femtosecond pulsed laser Dru Morrish, Xiaosong Gan and Min Gu Centre for Micro-Photonics, School of Biophysical
More informationCryogenically cooled 946nm Nd:YAG laser
Cryogenically cooled 946nm Nd:YAG laser S. J. Yoon* and J. I. Mackenzie Optoelectronics Research Centre, University of Southampton, Highfield, Southampton SO17 1BJ, UK *sjy1g12@orc.soton.ac.uk Abstract:
More informationIn a metal, how does the probability distribution of an electron look like at absolute zero?
1 Lecture 6 Laser 2 In a metal, how does the probability distribution of an electron look like at absolute zero? 3 (Atom) Energy Levels For atoms, I draw a lower horizontal to indicate its lowest energy
More informationConfocal Microscopy Imaging of Single Emitter Fluorescence and Hanbury Brown and Twiss Photon Antibunching Setup
1 Confocal Microscopy Imaging of Single Emitter Fluorescence and Hanbury Brown and Twiss Photon Antibunching Setup Abstract Jacob Begis The purpose of this lab was to prove that a source of light can be
More informationEXTREME ULTRAVIOLET AND SOFT X-RAY LASERS
Chapter 7 EXTREME ULTRAVIOLET AND SOFT X-RAY LASERS Hot dense plasma lasing medium d θ λ λ Visible laser pump Ch07_00VG.ai The Processes of Absorption, Spontaneous Emission, and Stimulated Emission Absorption
More informationUnit-2 LASER. Syllabus: Properties of lasers, types of lasers, derivation of Einstein A & B Coefficients, Working He-Ne and Ruby lasers.
Unit-2 LASER Syllabus: Properties of lasers, types of lasers, derivation of Einstein A & B Coefficients, Working He-Ne and Ruby lasers. Page 1 LASER: The word LASER is acronym for light amplification by
More informationSUPPLEMENTARY INFORMATION
doi:10.1038/nature10721 Experimental Methods The experiment was performed at the AMO scientific instrument 31 at the LCLS XFEL at the SLAC National Accelerator Laboratory. The nominal electron bunch charge
More information*Corresponding author:
Large-energy, narrow-bandwidth laser pulse at 1645 nm in a diode-pumped Er:YAG solid-state laser passively Q-switched by a monolayer graphene saturable absorber Rong Zhou, 1 Pinghua Tang, 1 Yu Chen, 1
More informationElectrically switchable organo inorganic hybrid for a white-light laser source
Supporting Information Electrically switchable organo inorganic hybrid for a white-light laser source Jui-Chieh Huang 1,, Yu-Cheng Hsiao 2,, Yu-Ting Lin 2, Chia-Rong Lee 3 & Wei Lee 2,* 1 Institute of
More informationLaser heating of noble gas droplet sprays: EUV source efficiency considerations
Laser heating of noble gas droplet sprays: EUV source efficiency considerations S.J. McNaught, J. Fan, E. Parra and H.M. Milchberg Institute for Physical Science and Technology University of Maryland College
More informationEE485 Introduction to Photonics
Pattern formed by fluorescence of quantum dots EE485 Introduction to Photonics Photon and Laser Basics 1. Photon properties 2. Laser basics 3. Characteristics of laser beams Reading: Pedrotti 3, Sec. 1.2,
More informationLasers and Electro-optics
Lasers and Electro-optics Second Edition CHRISTOPHER C. DAVIS University of Maryland III ^0 CAMBRIDGE UNIVERSITY PRESS Preface to the Second Edition page xv 1 Electromagnetic waves, light, and lasers 1
More informationFigure 1 Relaxation processes within an excited state or the ground state.
Excited State Processes and Application to Lasers The technology of the laser (Light Amplified by Stimulated Emission of Radiation) was developed in the early 1960s. The technology is based on an understanding
More informationPhys 2310 Mon. Dec. 4, 2017 Today s Topics. Begin supplementary material: Lasers Reading for Next Time
Phys 2310 Mon. Dec. 4, 2017 Today s Topics Begin supplementary material: Lasers Reading for Next Time 1 By Wed.: Reading this Week Lasers, Holography 2 Homework this Week No Homework this chapter. Finish
More informationSignal regeneration - optical amplifiers
Signal regeneration - optical amplifiers In any atom or solid, the state of the electrons can change by: 1) Stimulated absorption - in the presence of a light wave, a photon is absorbed, the electron is
More informationSupplementary Figure 1. Potential energy, volume, and molecular distribution of the
1 2 3 4 5 6 7 8 Supplementary Figure 1. Potential energy, volume, and molecular distribution of the organic substrates prepared by MD simulation. (a) Change of the density and total potential energy of
More informationHONG JIN KONG Department of Physics, KAIST, Gusong-dong, Yusong-gu, Daejon Korea
Beam combined high energy/high power laser system operating at a repetition rate over 10Hz for laser fusion driver using stimulated Brillouin scattering phase conjugate mirrors HONG JIN KONG Department
More informationLecture 7 Pumping & Popula3on Inversion*
Lecture 7 Pumping & Popula3on Inversion* Min Yan Op3cs and Photonics, KTH 15/04/16 1 * Some figures and texts belong to: O. Svelto, Principles of Lasers, 5th Ed., Springer. Reading Principles of Lasers
More informationLaser Basics. What happens when light (or photon) interact with a matter? Assume photon energy is compatible with energy transition levels.
What happens when light (or photon) interact with a matter? Assume photon energy is compatible with energy transition levels. Electron energy levels in an hydrogen atom n=5 n=4 - + n=3 n=2 13.6 = [ev]
More informationLaser Types Two main types depending on time operation Continuous Wave (CW) Pulsed operation Pulsed is easier, CW more useful
Main Requirements of the Laser Optical Resonator Cavity Laser Gain Medium of 2, 3 or 4 level types in the Cavity Sufficient means of Excitation (called pumping) eg. light, current, chemical reaction Population
More informationLaser Dissociation of Protonated PAHs
100 Chapter 5 Laser Dissociation of Protonated PAHs 5.1 Experiments The photodissociation experiments were performed with protonated PAHs using different laser sources. The calculations from Chapter 3
More informationSingle Emitter Detection with Fluorescence and Extinction Spectroscopy
Single Emitter Detection with Fluorescence and Extinction Spectroscopy Michael Krall Elements of Nanophotonics Associated Seminar Recent Progress in Nanooptics & Photonics May 07, 2009 Outline Single molecule
More informationInvestigation of absorption pump light distribution in edged-pumped high power Yb:YAG\YAG disk laser
International Journal of Optics and Photonics (IJOP) Vol. 5, No. 1, Winter-Spring 2011 Investigation of absorption pump light distribution in edged-pumped high power Yb:YAG\YAG disk laser H. Aminpour 1,*,
More informationHighly Efficient and Anomalous Charge Transfer in van der Waals Trilayer Semiconductors
Highly Efficient and Anomalous Charge Transfer in van der Waals Trilayer Semiconductors Frank Ceballos 1, Ming-Gang Ju 2 Samuel D. Lane 1, Xiao Cheng Zeng 2 & Hui Zhao 1 1 Department of Physics and Astronomy,
More informationInterested in exploring science or math teaching as a career?
Interested in exploring science or math teaching as a career? Start with Step 1: EDUC 2020 (1 credit) Real experience teaching real kids! No commitment to continue with education courses Registration priority
More informationMetal Vapour Lasers Use vapoured metal as a gain medium Developed by W. Silfvast (1966) Two types: Ionized Metal vapour (He-Cd) Neutral Metal vapour
Metal Vapour Lasers Use vapoured metal as a gain medium Developed by W. Silfvast (1966) Two types: Ionized Metal vapour (He-Cd) Neutral Metal vapour (Cu) All operate by vaporizing metal in container Helium
More information3.5x10 8 s/cm (c axis, 22 C, 1KHz) α x =11x10-6 / C, α y =9x10-6 / C, α z =0.6x10-6 / C
Potassium Titanyl Phosphate (KTiOPO 4 or KTP) KTP (or KTiOPO 4 ) crystal is a nonlinear optical crystal, which possesses excellent nonlinear and electro-optic properties. It has large nonlinear optical
More informationColloidal Single-Layer Quantum Dots with Lateral Confinement Effects on 2D Exciton
Supporting Information Colloidal Single-Layer Quantum Dots with Lateral Confinement Effects on 2D Exciton Ho Jin,, Minji Ahn,,,, Sohee Jeong,,, Jae Hyo Han,,, Dongwon Yoo,, Dong Hee Son, *, and Jinwoo
More informationSemiconductor Optoelectronics Prof. M. R. Shenoy Department of Physics Indian Institute of Technology, Delhi
Semiconductor Optoelectronics Prof. M. R. Shenoy Department of Physics Indian Institute of Technology, Delhi Lecture - 1 Context and Scope of the Course (Refer Slide Time: 00:44) Welcome to this course
More informationHigh Power Diode Lasers
Lecture 10/1 High Power Diode Lasers Low Power Lasers (below tenth of mw) - Laser as a telecom transmitter; - Laser as a spectroscopic sensor; - Laser as a medical diagnostic tool; - Laser as a write-read
More informationControlling Graphene Ultrafast Hot Carrier Response from Metal-like. to Semiconductor-like by Electrostatic Gating
Controlling Graphene Ultrafast Hot Carrier Response from Metal-like to Semiconductor-like by Electrostatic Gating S.-F. Shi, 1,2* T.-T. Tang, 1 B. Zeng, 1 L. Ju, 1 Q. Zhou, 1 A. Zettl, 1,2,3 F. Wang 1,2,3
More informationSemiconductor Disk Laser on Microchannel Cooler
Semiconductor Disk Laser on Microchannel Cooler Eckart Gerster An optically pumped semiconductor disk laser with a double-band Bragg reflector mirror is presented. This mirror not only reflects the laser
More informationMs. Monika Srivastava Doctoral Scholar, AMR Group of Dr. Anurag Srivastava ABV-IIITM, Gwalior
By Ms. Monika Srivastava Doctoral Scholar, AMR Group of Dr. Anurag Srivastava ABV-IIITM, Gwalior Unit 2 Laser acronym Laser Vs ordinary light Characteristics of lasers Different processes involved in lasers
More informationTentative Schedule: Date, Place & Time Topics Sep.4 (Mo) No classes Labor Day Holiday Exam 1 Exam 2 Over Chapters 4-6
Tentative Schedule: Date, Place & Time Topics 1 Aug. 8 (Mo) 394; 5:00-6:15 Introduction, Spontaneous and Stimulated Transitions (Ch. 1) Lecture Notes Aug. 30 (We) 394; 5:00-6:15 Spontaneous and Stimulated
More informationSpectroscopic investigations of Rb- and Cs- rare gas systems
Spectroscopic investigations of Rb- and Cs- rare gas systems S. J. Davis *, W. T. Rawlins, K. L. Galbally-Kinney, and W.J. Kessler Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810
More informationEnhancing the laser power by stacking multiple dye-doped chiral polymer films
Enhancing the laser power by stacking multiple dye-doped chiral polymer films Yuhua Huang, Tsung-Hsien Lin, Ying Zhou, and Shin-Tson Wu College of Optics and Photonics, University of Central Florida, Orlando,
More informationPHYSICS nd TERM Outline Notes (continued)
PHYSICS 2800 2 nd TERM Outline Notes (continued) Section 6. Optical Properties (see also textbook, chapter 15) This section will be concerned with how electromagnetic radiation (visible light, in particular)
More informationLaser Fundamentals and its Applications. Photonic Network By Dr. M H Zaidi
Laser Fundamentals and its Applications LASER LASER is acronym of Light Amplification by Stimulated Emission of Radiation. http://www.semicon.toshiba.co.jp Lasers Outline Introduction and Overview Theory
More informationWhat Makes a Laser Light Amplification by Stimulated Emission of Radiation Main Requirements of the Laser Laser Gain Medium (provides the light
What Makes a Laser Light Amplification by Stimulated Emission of Radiation Main Requirements of the Laser Laser Gain Medium (provides the light amplification) Optical Resonator Cavity (greatly increase
More informationIntroduction to Laser Material Processing. ME 677: Laser Material Processing Instructor: Ramesh Singh 1
Introduction to Laser Material Processing 1 Outline Brief History Design of Laser cavity Stability Types of Lasers 2 Laser History 1917 - Albert Einstein: Theoretical prediction of stimulated emission
More informationFemtosecond laser microfabrication in. Prof. Dr. Cleber R. Mendonca
Femtosecond laser microfabrication in polymers Prof. Dr. Cleber R. Mendonca laser microfabrication focus laser beam on material s surface laser microfabrication laser microfabrication laser microfabrication
More informationINTERFEROMETRIC METHOD FOR THE STUDY OF SPATIAL PHASE MODULATION INDUCED BY LIGHT IN DYE-DOPED DNA COMPLEXES
Romanian Reports in Physics, Vol. 67, No. 4, P. 1373 1382, 2015 Dedicated to International Year of Light 2015 INTERFEROMETRIC METHOD FOR THE STUDY OF SPATIAL PHASE MODULATION INDUCED BY LIGHT IN DYE-DOPED
More informationMODELING OF ABOVE-THRESHOLD SINGLE-MODE OPERATION OF EDGE- EMITTING DIODE LASERS
MODELING OF ABOVE-THRESHOLD SINGLE-MODE OPERATION OF EDGE- EMITTING DIODE LASERS A. P. Napartovich, N. N. Elkin, A. G. Sukharev, V. N. Troshchieva, and D. V. Vysotsky Troitsk Institute for Innovation and
More informationDiagnostic Systems for Characterizing Electron Sources at the Photo Injector Test Facility at DESY, Zeuthen site
1 Diagnostic Systems for Characterizing Electron Sources at the Photo Injector Test Facility at DESY, Zeuthen site Sakhorn Rimjaem (on behalf of the PITZ team) Motivation Photo Injector Test Facility at
More information