All-optically controllable random laser based on a dye-doped polymer-dispersed liquid crystal with nano-sized droplets
|
|
- Erik Stevenson
- 5 years ago
- Views:
Transcription
1 All-optically controllable random laser based on a dye-doped polymer-dispersed liquid crystal with nano-sized droplets C.-R. Lee, 1, * S.-H. Lin, 1 C.-H. Guo, 1 S.-H. Chang, 1 T.-S. Mo, 2 and S.-C. Chu 3 1 Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan 701, Republic of China 2 Department of Electronic Engineering, Kun Shan University of Technology, Tainan, Taiwan 710, Republic of China 3 Department of Physics, National Cheng Kung University, Tainan, Taiwan 701, Republic of China *crlee@mail.ncku.edu.tw Abstract: This study elucidates for the first time an all-optically controllable random laser in a dye-doped polymer-dispersed liquid crystal (DDPDLC) with nano-sized LC droplets. Experimental results demonstrate that the lasing intensity of the random laser can be controlled to decrease by increasing irradiation time/intensity of one green beam, and increase by increasing the irradiation time of one red beam. The all-optical controllability of the random laser is attributed to the green (red)-beaminduced isothermal nematic isotropic (isotropic nematic) phase transition in LC droplets by trans cis (cis trans back) isomerization of azo dyes. This isomerization may decrease (increase) the difference between the refractive indices of the LC droplets and the polymer, thereby increasing (decreasing) the diffusion constant (or transport mean free path), subsequently decreasing the scattering strength and, thus, random lasing intensity Optical Society of America OCIS codes: ( ) All-optical devices; ( ) Liquid crystals; ( ) Lasers and laser optics References and links 1. N. M. Lawandy, R. M. Balachandran, A. S. L. Gomes, and E. Sauvain, Laser action in strongly scattering media, Nature 368(6470), (1994). 2. H. Cao, Y. G. Zhao, S. T. Ho, E. W. Seelig, Q. H. Wang, and R. P. H. Chang, Random laser action in semiconductor powder, Phys. Rev. Lett. 82(11), (1999). 3. D. S. Wiersma, The smallest random laser, Nature 406(6792), (2000). 4. V. M. Apalkov, M. E. Raikh, and B. Shapiro, Random resonators and prelocalized modes in disordered dielectric films, Phys. Rev. Lett. 89(1), (2002). 5. R. C. Polson, and Z. V. Vardeny, Random lasing in human tissues, Appl. Phys. Lett. 85(7), (2004). 6. Q. H. Song, L. Wang, S. M. Xiao, X. C. Zhou, L. Y. Liu, and L. Xu, Random laser emission from a surfacecorrugated waveguide, Phys. Rev. B 72(3), (2005). 7. S. V. Frolov, Z. V. Varderny, K. Yoshino, A. Zakhidov, and R. H. Baughman, Stimulated emission in high-gain organic media, Phys. Rev. B 59(8), R5284 R5287 (1999). 8. D. S. Wiersma, M. Colocci, R. Righini, and F. Aliev, Temperature-controlled light diffusion in random media, Phys. Rev. B 64(14), (2001). 9. S. M. Morris, A. D. Ford, M. N. Pivnenko, and H. J. Coles, Electronic control of nonresonant random lasing from a dye-doped smectic A* liquid crystal scattering device, Appl. Phys. Lett. 86, (2005). 10. G. Strangi, S. Ferjani, V. Barna, A. De Luca, C. Versace, N. Scaramuzza, and R. Bartolino, Random lasing and weak localization of light in dye-doped nematic liquid crystals, Opt. Express 14(17), (2006). 11. Q. H. Song, S. M. Xiao, X. C. Zhou, L. Y. Liu, L. Xu, Y. G. Wu, and Z. S. Wang, Liquid-crystal-based tunable high-q directional random laser from a planar random microcavity, Opt. Lett. 32(4), (2007). 12. S. Ferjani, V. Barna, A. De Luca, C. Versace, and G. Strangi, Random lasing in freely suspended dye-doped nematic liquid crystals, Opt. Lett. 33(6), (2008). 13. Q. H. Song, L. Y. Liu, L. Xu, Y. G. Wu, and Z. S. Wang, Electrical tunable random laser emission from a liquid-crystal infiltrated disordered planar microcavity, Opt. Lett. 34(3), (2009). 14. S. Gottardo, S. Cavalieri, O. Yaroshchuk, and D. S. Wiersma, Quasi-two-dimensional diffusive random laser action, Phys. Rev. Lett. 93(26), (2004). (C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2406
2 15. Y. J. Liu, X. W. Sun, H. I. Elim, and W. Ji, Gain narrowing and random lasing from dye-doped polymer dispersed liquid crystals with nanoscale liquid crystal droplets, Appl. Phys. Lett. 89(1), (2006). 16. S. Ferjani, L. Sorriso-Valvo, A. De Luca, V. Barna, R. De Marco, and G. Strangi, Statistical analysis of random lasing emission properties in nematic liquid crystals, Phys. Rev. E Stat. Nonlin. Soft Matter Phys. 78(1), (2008). 17. D. S. Wiersma, The physics and applications of random lasers, Nat. Phys. 4(5), (2008). 18. A. Lagendijk and M. van Albada, Observation of weak localization of light in a random medium, Phys. Rev. Lett. 55(24), (1985). 19. E. Akkermans, P. E. Wolf, and R. Maynard, Coherent backscattering of light by disordered media: Analysis of the peak line shape, Phys. Rev. Lett. 56(14), (1986). 20. M. van Alvada, M. B. van der Mark, and A. Lagendijk, Observation of weak localization of light in a finite slab: Anisotropy effects and light path classification, Phys. Rev. Lett. 58(4), (1987). 21. P. C. de Oliveira, A. E. Perkins, and N. M. Lawandy, Coherent backscattering from high-gain scattering media, Opt. Lett. 21(20), (1996). 22. H.-K. Lee, A. Kanazawa, T. Shiono, T. Ikeda, T. Fujisawa, M. Aizawa, and B. Lee, All-optically controllable polymer/liquid crystal composite films containing the azobenzene liquid crystal, Chem. Mater. 10(5), (1998). 23. H.-C. Yeh, G.-H. Chen, C.-R. Lee, and T.-S. Mo, Optically switchable biphotonic gratings based on dye-doped cholesteric liquid crystal films, Appl. Phys. Lett. 90(26), (2007). 1. Introduction Random lasers have attracted considerable attention over the last decade due to their interesting fundamentals and potential applications in photonics and bio-medicine [1 6]. Many disordered materials, such as TiO 2 and ZnO powders [2], polymers [7], human tissues [5], dye-doped liquid crystals (DDLCs) [8 13,16], and dye-doped polymer-dispersed LCs (DDPDLCs) [14,15] can be employed to generate random lasing. A coherent random lasing can be obtained by either extended or localized modes via the multi-scattering process with or without a coherent feedback effect. When the time photons remain in the gain medium is sufficient, the amplification of fluorescence can exceed optical loss, such that the random lasing can occur [17]. The diffusion constant of photons in a disordered medium plays a key role in the occurrence of random lasing [4,6 8,14]. For instance, in a DDPDLC system, the diffusion constant strongly depends on the difference between the refractive indices of the LC droplets and the polymer [14,15]. As this difference increases, the diffusion constant decreases, thereby increasing scattering strength, and, in turn, random lasing can be enhanced. In the above mentioned materials, only those associated with LCs can be used to control lasing characteristics of a random laser because of the externally flexible controllability of LC orientation and, thus, the refractive index of LC. Some thermally and electrically controllable random lasers have been developed using LC-associated materials [8,9,11,13,14]. However, no study has investigated optically controllable random lasers. Thus, this study for the first time investigates an all-optically controllable random laser based on a DDPDLC with nanosized LC droplets. Experimental results demonstrate that the obtained random lasing intensity can be controlled to decrease with increasing the irradiation time/intensity of one green beam, and increased by increasing the irradiation time of one red beam. This all-optical controllability of random lasing can be attributed to the green-beam-induced isothermal nematic isotropic (N I) phase transition and red-beam-induced isothermal isotropic nematic (I N) phase transition in LC droplets by trans cis and cis trans back isomerizations of azo dyes, respectively. The former (latter) mechanism can decrease (increase) the difference between the refractive indices of the LC droplets and the polymer, thereby increasing (decreasing) the diffusion constant (or transport mean free path), which finally causes the decrease (increase) of scattering strength and, thus, random lasing intensity. 2. Sample preparation and experimental setups The materials used in this study are 34.47wt% nematic LC (NLC) E7 (n e = and n o = at 20 C for λ = 589nm; n i (n e + 2n o )/3 = in the isotropic phase) (Merck), 45.24wt% monomer trimethylolpropane triacrylate, 7.88wt% cross-linking monomer N- vinylpyrrollidone, 0.60wt% photo-initiator rose bengal, 0.93wt% coinitiator N-phenylglycine, (C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2407
3 9.50wt% surfactant octanoic acid, 0.25wt% azo dye D2 (all from Aldrich), and 1.13wt% laser dye 4-dicyanmethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) (Exciton). These materials are uniformly mixed and injected into an empty cell, which is fabricated using two indium-tin-oxide-coated glass slides separated by two plastic spacers, each 6µm thick. After the mixture fills the entire cell via the capillary effect, the cell is then illuminated by a uniform green laser beam from a diode-pumped solid state laser (532nm) with an intensity of 400mW/cm 2 (irradiated radius of 0.15cm) for 4min to form a DDPDLC. The inset on the bottom of Fig. 1 shows a SEM photograph of the formed DDPDLC, in which the size of LC droplets occupying the black regions, which are randomly dispersed in the polymer matrix (grey regions), are primarily distributed at 30 70nm. These droplets serve as good scatterers for fluorescence photons inside the cell because of the strong mismatch between the refractive indices of the LC droplets and the polymer. Figure 1 shows the experimental setup for examining the all-optically controllable random lasing emission of the DDPDLC. One pumped laser beam, derived from a Q-switched Nd:YAG second harmonic generation (SHG) pulse laser (wavelength, 532 nm) with a pulse duration of 8ns, repetition rate of 10Hz and pumped energy, E, is focused by a cylindrical lens (focal length, 15cm) on a stripe region of the DDPDLC. The excited stripe is 3mm long and Fig. 1. Top view of experimental setup for examining the all-optically controllable random lasing emission of the DDPDLC cell (with a 6µm-thickness). The green and red beams are both circularly polarized (λ/2, half waveplate for 532nm; PBS, polarizing beam splitter). The inset on the bottom is an SEM photograph of the DDPDLC cell, in which the length of the white bar is 100nm and the black regions are places occupied by nano-sized LC droplets in the polymer matrix (grey regions). 0.3mm wide. A fiber-optic probe of a fiber-based spectrometer (HR4000, Ocean Optics, resolution: ~1nm) is placed such that it faces the bottom edge of the cell to record the lateral random lasing output of the DDPDLC. A half-wave plate (λ/2 for 532 nm) and polarizing beam splitter (PBS) are placed in front of the lens for varying incident pulse energy. During the experiments in which the random laser was all-optically controlled, one CW circularly # $15.00 USD 100nm Received 16 Dec 2009; revised 15 Jan 2010; accepted 16 Jan 2010; published 21 Jan 2010 (C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2408
4 polarized green beam (from a diode-pumped solid-state laser, wavelength: 532nm, output power 1W) and one CW circularly polarized red beam (from a He-Ne laser, wavelength: 633 nm, output power 35mW) are installed to, or not to, pre-illuminate the excited cell stripe. The incident angles relative to the cell normal for the green and red beams are both 12. The premeasured absorption spectra (not shown) of the DDPDLC cell indicates that it is distributed in the nm visible region. 3. Results and discussion Before conducting the experiments investigating the all-optical controllability of random lasing, the energy threshold of incident pumped pulses for generating random lasing in the cell must be determined. At this stage, both green and red beams are turned off. Figure 2(a) shows the variation in measured fluorescence spectra with a pumped energy of E = 11 22µJ/pulse. Figure 2(b) plots and summarizes experimental data, in which variations in peak intensity of fluorescence output and the corresponding full widths at half-maximum (FWHM) with the pumped energy are presented. Notably, the peak intensity of fluorescence output increases nonlinearly as pumped energy increases. An energy threshold (E th ) ~16µJ/pulse can be obtained, which is indicative of gain narrowing. The inset in Fig. 2(b) is a photograph of the emission pattern at E = 22µJ/pulse. In Fig. 2(a), several narrow random lasing peaks with 1nm-FWHM (the narrowest is λ~0.8nm at E = 22µJ/pulse in the inset) appear at the top of the fluorescence envelopes when pulse energy exceeds E th. The grey dotted-curve of the fluorescence spectrum of the DDPDLC cell between 580nm and 650nm is also displayed in Fig. 2(a). Those discrete spikes of random lasing emission are distributed around the region of nm which is near the wavelength (~600nm) of the maxima of the fluorescence emission. The absorption spectrum of the cell (not shown) indicates that the re-absorption effect may cause suppression effect of the amplification of the fluorescence emission at 610nm. This is the possible reason that the strongest lasing spike does not occur at 610nm. To ascertain the underlying mechanism of the random lasing shown in Fig. 2, this work performs the coherent backscattering (CBS) experiment by probing the DDPDLC cell with the use of a weak 633nm laser beam [18]. The measured coherent cone width of backscattering is ~9mrad. The coherent cone θ is relative to the transport mean free path l* (defined as the average distance a photon travels before its direction of propagation is Fig. 2. Variations of (a) measured fluorescence spectra and (b) peak intensity of fluorescence output and corresponding full-width at half-maxima (FWHM) with incident pumped energy. The insets in (b) and (a) are the emission pattern and magnified fluorescence spectrum of the narrow random lasing peaks at E = 22µJ/pulse, respectively. completely randomized) by θ λ/(2πl*) [19 21]. Substituting λ = 633nm and θ = 9mrad into this relation, the transport mean free path is calculated to be approximately 11.2µm. With the satisfactory of the condition l*/λ > 1, the random lasing observed in this work (Fig. 2) is (C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2409
5 attributable to the weak localization of the fluorescence photons via multiple scattering of the LC droplets with coherent feedback in our DDPDLC cell [10,12,15 17]. The following experiments investigate all-optical controllability of the random lasing emission with a fixed E = 22µJ/pulse by irradiation via one green and one red beam on the DDPDLC cell. Figure 3(a) (3(b)) show different random lasing emissions generated after the DDPDLC is irradiated by the green beam at different irradiation times t G = 0 100s (different irradiation intensities of I G = 0 450mW/cm 2 ) and a fixed irradiation intensity of I G = 450mW/cm 2 (a fixed irradiation time of t G = 2.5min). The intensity of the random lasing signal can be controlled to decrease by increasing t G (or I G ). Moreover, Fig. 4(a) shows experimental results for the effect of irradiation by the red beam on the random lasing emission via the following three steps. (I) Without illumination by the green and red beams (I G = I R = 0), the cell is excited by pumped pulses and a strong random lasing emission is acquired (black curve in Fig. 4(a)). (II) The green beam with I G = 450mW/cm 2 is turned on to illuminate the cell for t G = 2.5min (I R = 0); the cell is then excited by pumped pulses to generate a weak fluorescence emission, which is not a lasing emission (red curve in Fig. 4(a)). (III) The green beam is turned off (I G = 0), and the red beam at I R = 1000mW/cm 2 is turned on Fig. 3. Variations of the random lasing emission with (a) irradiation time (fixed at I G = 450mW/cm 2 ) and (b) irradiation intensity (fixed at t G = 2.5min) of one circularly polarized green beam. The pumped pulse energy is 22µJ/pulse. Fig. 4. (a) Variation of the random lasing signal as irradiation time (t R) of the red beam (fixed irradiation intensity of I R = 1000mW/cm 2 ) increases. (b) Variations in normalized peak intensity of random lasing output with t G and t R. to irradiate the cell. After irradiation by the red beam for t R = 3, 6, and 9min, the cell is then excited by pumped pulses and thereby generates different random lasing signals (orange, pink, and green curves, respectively, in Fig. 4(a)). The intensity of the obtained random lasing (C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2410
6 signal can be controlled to increase back by increasing t R. Figure 4(b) summarizes and plots the variations of normalized peak intensity of the random lasing output with t G and t R. Clearly, the DDPDLC random laser has one all-optically controllable feature the random lasing emission can decay gradually and increase again when irradiated by the green and red beams for an increasing duration, respectively. The all-optical controllability of decreasing (increasing) random lasing intensity is mainly attributable to green (red)-beam-induced isothermal N I (I N) phase transition in the LC droplets [22] via trans cis (cis trans back) isomerization of the D2 dyes. The details are as follows. All D2 dyes are stable trans-isomers in darkness. The rod-like trans-d2 dyes can be aligned with LCs via the guest-host effect in each LC droplet of cell. In reference to the absorption spectrum of D2 dye reported in our previous study [23], azo dyes can absorb green light (circularly polarized) and typically transform to curve cis-state and then disturb the order of the LCs in each droplet. As t G or the strength of I G increases, the concentration of azo dyes converting into cis-isomers increases. This can cause LCs to gradually change from the nematic to the isotropic phase isothermally, and the difference between the refractive indices of the LC droplet and the polymer can markedly decrease from (n N -n p ) to (n i -n p ), where n N and n i are the refractive indices of an LC droplet in the nematic and isotropic phase, respectively, and n p is the refractive index of the polymer ( ) [15]. The diffusion constant of photons (D) in a disorder medium can be represented by D = (vl*)/3 [8], where l* is the transport mean free path and v the transport velocity of photons in the DDPDLC sample. Decreasing the difference between the refractive indices of the LC droplets and the polymer can increase the diffusion constant (or transport mean free path), thereby decreasing the scattering strength of the photons in the cell. In turn, random lasing intensity can decrease as t G or I G increases. As mentioned, most D2 dyes can lie in a cis-state when they absorb green light, which can decay the random lasing emission of the DDPDLC cell. Once the green beam is turned off and the cell is irradiated by the red beam, the cis-d2 dyes can transform rapidly back to the trans-state [23]. An increasing number of dyes can become rod-like trans dyes and the LC droplets will gradually return to the nematic phase as the irradiation time of the red beam increases. The difference in the refractive indices of the LC droplets and the polymer will then gradually increase, causing the diffusion constant to decrease and, thus, scattering strength increases. Therefore, the intensity of random lasing recovers as t R increases. To demonstrate that the all-optical controllability of the random lasing emission does not result from the thermal effect-induced phase transition in LC droplets under illumination of the CW laser beam, two separate experiments are conducted. Figures 5(a) and 5(b) present and compare experimental results. The black and red curves in Fig. 5(a) represent the measured random lasing signals at cell temperatures of T = 23 and 80 C, respectively, with I G = I R = 0. The random lasing signal decays considerably when cell temperature is increased from 23 C to 80 C, which exceeds the clear point of the E7 LC (~60 C). This is due to the thermal effect-induced N I phase transition in LC droplets, causing the decrease in the difference between the refractive indices of the LC droplets and the polymer. This can lead to the decay of scattering strength and thus random lasing intensity. Cell temperature then naturally decreases to 23 C within 4min. The random lasing signal is then measured again (green curve in Fig. 5(a)). The peak intensity of the random lasing signal almost recovers to its original value. This is because the LC droplets all return back to the nematic phase via thermal relaxation. On the other hand, the black and red curves in Fig. 5(b) represent the obtained random lasing signals without and with pre-irradiation of the green beam with I G = 450mW/cm 2 for t G = 2.5min, respectively, at 23 C. The random lasing signal decays significantly when the cell has been pre-irradiated by the green beam. Afterwards, the green beam is turned off (I G = 0) for 4min, and then the cell is re-excited by pumped pulses. The obtained signal (green curve in Fig. 5(b)) cannot recover to its original state prior to irradiation by the green beam. The discrepancy between experimental results (Figs. 5(a) and 5(b)) implies that the all-optical controllability of the random lasing signal (Figs. 3 and 4) is not induced by the thermal effect, but rather the photoisomerization effect induced phase transition of LC droplets. (C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2411
7 4. Conclusion Fig. 5. (a) Random lasing signals measured in order at cell temperatures of 23, 80, and 23 C (black, red and green curves, respectively). The time required for the cell temperature to naturally relax from 80 to 23 C is roughly 4min. (b) The random lasing signals measured at 23 C in order as the pre-irradiation intensity of the green beam is set at 0, 450 (for 2.5min) and 0 (for 4min) mw/cm 2 (black, red and green curves, respectively). In summary, an all-optically controllable random laser based on a DDPDLC with nano-sized LC droplets is investigated and reported for the first time. Experimental results reveal that irradiation of one CW green and red beam can all-optically control the lasing intensity of the generated DDPDLC random laser. The causes of the controllability of the random lasing emission are attributable to the green-beam induced isothermal N I phase transition via trans cis isomerization and the red-beam induced isothermal I N phase transition via cis trans back isomerization in LC droplets. The former (latter) may cause the difference between the refractive indices of the LC droplets and the polymer to decrease (increase) and, thus, increase (decrease) the diffusion constant (or transport mean free path) and decrease (increase) scattering strength, which in turn decreases (increases) random lasing intensity. The thermal effect is excluded from possible mechanisms causing controllability of the random laser. Valuable applications for such an all-optically controllable random laser can be found in integrated photonics. Acknowledgments The authors would like to thank the National Science Council of the Republic of China, Taiwan (Contract No. NSC M MY3) and the Advanced Optoelectronic Technology Center, National Cheng Kung University, under projects from the Ministry of Education for financially supporting this research. We greatly appreciate Ted Knoy for editorial assistance. (C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2412
All-optically controllable nanoparticle random laser in a well-aligned laser-dye-doped liquid crystal
Vol. 24, No. 25 12 Dec 2016 OPTICS EXPRESS 28739 All-optically controllable nanoparticle random laser in a well-aligned laser-dye-doped liquid crystal CHI-HUANG CHANG, 1,2 CHIE-TONG KUO, 3 HAN-YING SUN,
More informationWidely tunable photonic bandgap and lasing emission in enantiomorphic cholesteric liquid crystal templates
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry C. This journal is The Royal Society of Chemistry 2017 Widely tunable photonic bandgap and lasing emission in enantiomorphic cholesteric
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 informationRandom Lasers - Physics & Application
Random Lasers - Physics & Application HuiCao Depts. of Applied Physics & Physics, Yale University Group members Jonathan Andreasen Yong Ling Bo Liu Heeso Noh Brandon Redding Xiaohua Wu Junying Xu Alexey
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 informationLIGHT AMPLIFICATION AND LASER EMISSION FROM SPECIAL MICROMETRIC CONFINED SYSTEMS
Digest Journal of Nanomaterials and Biostructures Vol. 12, No. 4, October-December 2017, p. 1233-1238 LIGHT AMPLIFICATION AND LASER EMISSION FROM SPECIAL MICROMETRIC CONFINED SYSTEMS V. BARNA * University
More informationImprovement of the diffraction properties in holographic polymer dispersed liquid crystal bragg gratings q
Optics Communications 218 (2003) 27 32 www.elsevier.com/locate/optcom Improvement of the diffraction properties in holographic polymer dispersed liquid crystal bragg gratings q YanJun Liu a, *, Bin Zhang
More informationHigh efficiency cholesteric liquid crystal lasers with an external stable resonator
High efficiency cholesteric liquid crystal lasers with an external stable resonator Hamidreza Shirvani-Mahdavi, 1,2 Shima Fardad, 2 Ezeddin Mohajerani, 1 and Shin-Tson Wu 2* 1 Laser and Plasma Research
More informationColor cone lasing emission in a dye-doped cholesteric liquid crystal with a single pitch
Color cone lasing emission in a dye-doped cholesteric liquid crystal with a single pitch C.-R. Lee, 1, * S.-H. Lin, 1 H.-C. Yeh, 1 T.-D. Ji, 1 K.-L. Lin, 1 T.-S. Mo, 2 C.-T. Kuo, 3 K.-Y. Lo, 4 S.-H. Chang,
More informationStudy on the Polarization of Random Lasers from Dye-Doped Nematic Liquid Crystals
Ye et al. Nanoscale Research Letters (2017) 12:27 DOI 10.1186/s11671-016-1778-x NANO EXPRESS Study on the Polarization of Random Lasers from Dye-Doped Nematic Liquid Crystals Lihua Ye 1*, Chong Zhao 1,
More informationliquid crystal films*
Optical effects based on dye-doped liquid crystal films* Andy Y. - G. Fuh ( 傅永貴 ) Department of Physics, and Institute of Electro-optical Science and Engineering, National Cheng Kung University, Tainan,
More informationRandom lasing from granular surface of waveguide with blends of PS and PMMA
Random lasing from granular surface of waveguide with blends of PS and PMMA Xuanke Zhao, 1,2 Zhaoxin Wu, 1,* Shuya Ning, 1 Shixiong Liang, 1 Dawei Wang, 1 Xun Hou 1 1 Key Laboratory of Photonics Technology
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 informationLiquid Crystals IAM-CHOON 1(1100 .,4 WILEY 2007 WILEY-INTERSCIENCE A JOHN WILEY & SONS, INC., PUBLICATION. 'i; Second Edition. n z
Liquid Crystals Second Edition IAM-CHOON 1(1100.,4 z 'i; BICENTCNNIAL 1 8 0 7 WILEY 2007 DICENTENNIAL n z z r WILEY-INTERSCIENCE A JOHN WILEY & SONS, INC., PUBLICATION Contents Preface xiii Chapter 1.
More informationWaveguiding-assisted random lasing in epitaxial ZnO thin film
Waveguiding-assisted random lasing in epitaxial ZnO thin film P.-H. Dupont a), C. Couteau a)*, D. J. Rogers b), F. Hosseini Téhérani b), and G. Lérondel a) a) Laboratoire de Nanotechnologie et d Instrumentation
More informationDirect measurement of electric-field-induced birefringence in a polymer-stabilized blue-phase liquid crystal composite
Direct measurement of electric-field-induced birefringence in a polymer-stabilized blue-phase liquid crystal composite Jin Yan, Meizi Jiao, Linghui Rao, and Shin-Tson Wu* College of Optics and Photonics,
More informationGratings in Electrooptic Polymer Devices
Gratings in Electrooptic Polymer Devices Venkata N.P.Sivashankar 1, Edward M. McKenna 2 and Alan R.Mickelson 3 Department of Electrical and Computer Engineering, University of Colorado at Boulder, Boulder,
More informationWorkshop on Coherent Phenomena in Disordered Optical Systems May Random Laser - Physics & Application
2583-14 Workshop on Coherent Phenomena in Disordered Optical Systems 26-30 May 2014 Random Laser - Physics & Application Hui CAO Depts. of Applied Physics and Physics Yale University New Haven. U.S.A Random
More informationMicrofabricação em materiais poliméricos usando laser de femtossegundos
Microfabricação em materiais poliméricos usando laser de femtossegundos Prof. Cleber R. Mendonça http://www.fotonica.ifsc.usp.br University of Sao Paulo - Brazil students 77.000 52.000 undergrad. 25.000
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 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 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 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 informationOptics of complex micro structures
Optics of complex micro structures dielectric materials λ L disordered partially ordered ordered random multiple scattering liquid crystals quasi crystals (Fibonacci) photonic crystals Assembly of photonic
More informationRandom Laser of R6G Dye and TiO 2 Nanoparticles Doped in PMMA Polymer
Advances in Materials Physics and Chemistry, 211, 1, 2-25 doi:1.4236/ampc.211.124 Published Online September 211 (http://www.scirp.org/journal/ampc) Random Laser of R6G Dye and TiO 2 Nanoparticles Doped
More informationObservation of white-light amplified spontaneous emission from carbon nanodots under laser excitation
Observation of white-light amplified spontaneous emission from carbon nanodots under laser excitation Wen Fei Zhang, Li Bin Tang, Siu Fung Yu,* and Shu Ping Lau Department of Applied Physics, The Hong
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 informationWidely tunable nonlinear liquid crystal-based photonic crystals
Widely tunable nonlinear liquid crystal-based photonic crystals I. C. Khoo a, Yana Zhang a, A. Diaz a, J. Ding a, I. B. Divliansky c, Kito Holliday b, T. S. Mayer a, V. Crespi b, D. Scrymgeour c, V. Gopalan
More informationAnalysis of second-harmonic generation microscopy under refractive index mismatch
Vol 16 No 11, November 27 c 27 Chin. Phys. Soc. 19-1963/27/16(11/3285-5 Chinese Physics and IOP Publishing Ltd Analysis of second-harmonic generation microscopy under refractive index mismatch Wang Xiang-Hui(
More informationSupplementary Information
Electronic Supplementary Material (ESI) for Nanoscale. This journal is The Royal Society of Chemistry 2014 Supplementary Information Large-scale lithography-free metasurface with spectrally tunable super
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 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 informationDYE DOPED NEMATIC LIQUID CRYSTAL REORIENTATION IN A LINEAR POLARIZED LASER FIELD: THRESHOLD EFFECT
DYE DOPED NEMATIC LIQUID CRYSTAL REORIENTATION IN A LINEAR POLARIZED LASER FIELD: THRESHOLD EFFECT NICOLETA ESEANU* 1, CORNELIA UNCHESELU 2, I. PALARIE 3, B. UMANSKI 4 1 Department of Physics, ''Politehnica''
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 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 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 informationMP5: Soft Matter: Physics of Liquid Crystals
MP5: Soft Matter: Physics of Liquid Crystals 1 Objective In this experiment a liquid crystal display (LCD) is built and its functionality is tested. The light transmission as function of the applied voltage
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 informationECE185 LIQUID CRYSTAL DISPLAYS
ECE185 LIQUID CRYSTAL DISPLAYS Objective: To study characteristics of liquid crystal modulators and to construct a simple liquid crystal modulator in lab and measure its characteristics. References: B.
More informationTowards the Lasing Spaser: Controlling. Metamaterial Optical Response with Semiconductor. Quantum Dots
Towards the Lasing Spaser: Controlling Metamaterial Optical Response with Semiconductor Quantum Dots E. Plum, V. A. Fedotov, P. Kuo, D. P. Tsai, and N. I. Zheludev,, Optoelectronics Research Centre, University
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 informationPolarization control and sensing with two-dimensional coupled photonic crystal microcavity arrays. Hatice Altug * and Jelena Vučković
Polarization control and sensing with two-dimensional coupled photonic crystal microcavity arrays Hatice Altug * and Jelena Vučković Edward L. Ginzton Laboratory, Stanford University, Stanford, CA 94305-4088
More informationThree-Dimensional Dye Distribution in Photo- Oriented Liquid-Crystal Alignment Layers
Kent State University From the SelectedWorks of Peter Palffy-Muhoray April 1, 00 Three-Dimensional Dye Distribution in Photo- Oriented Liquid-Crystal Alignment Layers S. Bardon D. Coleman N. A. Clark T.
More informationDegenerate Four-Wave Mixing Experiments In Rose Bengal Dye Doped Gelatin Film.
The 1 st Regional Conference of Eng. Sci. NUCEJ Spatial ISSUE vol.11,no.1, 2008 pp 107-111 Degenerate Four-Wave Mixing Experiments In Rose Bengal Dye Doped Gelatin Film. Abstract Ahmad Y.Nooraldeen Centre
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 informationLaserphysik. Prof. Yong Lei & Dr. Yang Xu. Fachgebiet Angewandte Nanophysik, Institut für Physik
Laserphysik Prof. Yong Lei & Dr. Yang Xu Fachgebiet Angewandte Nanophysik, Institut für Physik Contact: yong.lei@tu-ilmenau.de; yang.xu@tu-ilmenau.de Office: Heisenbergbau V 202, Unterpörlitzer Straße
More informationQ. Shen 1,2) and T. Toyoda 1,2)
Photosensitization of nanostructured TiO 2 electrodes with CdSe quntum dots: effects of microstructure in substrates Q. Shen 1,2) and T. Toyoda 1,2) Department of Applied Physics and Chemistry 1), and
More informationDynamic studies of two-beam coupling on the holographic gratings based on liquid crystal±polymer composite lms
1 January 2001 Optics Communications 187 (2001) 193±198 www.elsevier.com/locate/optcom Dynamic studies of two-beam coupling on the holographic gratings based on liquid crystal±polymer composite lms A.Y.-G.
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 informationHysteresis-free and submillisecond-response polymer network liquid crystal
Hysteresis-free and submillisecond-response polymer network liquid crystal Yun-Han Lee, Fangwang Gou, Fenglin Peng and Shin-Tson Wu * CREOL, The College of Optics and Photonics, University of Central Florida,
More informationHYPER-RAYLEIGH SCATTERING AND SURFACE-ENHANCED RAMAN SCATTERING STUDIES OF PLATINUM NANOPARTICLE SUSPENSIONS
www.arpapress.com/volumes/vol19issue1/ijrras_19_1_06.pdf HYPER-RAYLEIGH SCATTERING AND SURFACE-ENHANCED RAMAN SCATTERING STUDIES OF PLATINUM NANOPARTICLE SUSPENSIONS M. Eslamifar Physics Department, BehbahanKhatamAl-Anbia
More informationWavelength switchable flat-top all-fiber comb filter based on a double-loop Mach-Zehnder interferometer
Wavelength switchable flat-top all-fiber comb filter based on a double-loop Mach-Zehnder interferometer Ai-Ping Luo, Zhi-Chao Luo,, Wen-Cheng Xu,, * and Hu Cui Laboratory of Photonic Information Technology,
More informationLight diffusion with gain and random lasers
PHYSICAL REVIEW E VOLUME 54, NUMBER 4 OCTOBER 1996 Light diffusion with gain and random lasers Diederik S. Wiersma * FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The
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 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 informationConstruction of a 100-TW laser and its applications in EUV laser, wakefield accelerator, and nonlinear optics
Construction of a 100-TW laser and its applications in EUV laser, wakefield accelerator, and nonlinear optics Jyhpyng Wang ( ) Institute of Atomic and Molecular Sciences Academia Sinica, Taiwan National
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 informationby applying two pairs of confocal cylindrical lenses
Title:Design of optical circulators with a small-aperture Faraday rotator by applying two pairs of confocal Author(s): Yung Hsu Class: 2nd year of Department of Photonics Student ID: M0100579 Course: Master
More informationPolarization-independent Pancharatnam-Berry phase lens system
Vol. 6, No. 6 4 Dec 018 OPTICS EXPRESS 3506 Polarization-independent Pancharatnam-Berry phase lens system TAO ZHAN, JIANGHAO XIONG, YUN-HAN LEE, AND SHIN-TSON WU* CREOL, The College of Optics and Photonics,
More informationDual-Wavelength Lasing from Organic Dye Encapsulated Metal-Organic Framework Microcrystals
Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2019 Electronic Supplementary Information Dual-Wavelength Lasing from Organic Dye Encapsulated Metal-Organic
More informationTwo-Photon Fabrication of Three-Dimensional Metallic Nanostructures for Plasmonic Metamaterials
Two-Photon Fabrication of Three-Dimensional Metallic Nanostructures for Plasmonic Metamaterials Atsushi ISHIKAWA 1 and Takuo TANAKA 1,2 1- Metamaterials Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198,
More informationThe objective of this project has been to develop new generations of random lasers based on inorganic particle - polymer nanocomposites.
Nanocomposite Random Lasers K. Piperaki, A. Stasinopoulos, D. Anglos, S. H. Anastasiadis, R. N. Das, and E. P. Giannelis Foundation for Research & Technology - Hellas (FO.R.T.H.) Institute of Electronic
More informationSupplementary documents
Supplementary documents Low Threshold Amplified Spontaneous mission from Tin Oxide Quantum Dots: A Instantiation of Dipole Transition Silence Semiconductors Shu Sheng Pan,, Siu Fung Yu, Wen Fei Zhang,
More informationModeling liquid-crystal devices with the three-dimensional full-vector beam propagation method
214 J. Opt. Soc. Am. A/ Vol. 23, No. 8/ August 26 Wang et al. Modeling liquid-crystal devices with the three-dimensional full-vector beam propagation method Qian Wang, Gerald Farrell, and Yuliya Semenova
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 informationRandom Laser Emission at Dual Wavelengths in a. Donor-Acceptor Dye Mixture Solution
Random Laser Emission at Dual Wavelengths in a Donor-Acceptor Dye Mixture Solution SUNITA KEDIA, * SUCHARITA SINHA Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 4 85, India
More informationSUPPLEMENTARY INFORMATION
doi:10.1038/nature12036 We provide in the following additional experimental data and details on our demonstration of an electrically pumped exciton-polariton laser by supplementing optical and electrical
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 informationDmitriy Churin. Designing high power single frequency fiber lasers
Dmitriy Churin Tutorial for: Designing high power single frequency fiber lasers Single frequency lasers with narrow linewidth have long coherence length and this is an essential property for many applications
More informationControl of Polymer Structures in Phase-Separated Liquid Crystal-Polymer Composite Systems
Japanese Journal of Applied Physics Vol. 44, No. 5A, 2005, pp. 3115 3120 #2005 The Japan Society of Applied Physics Control of Polymer Structures in Phase-Separated Liquid Crystal-Polymer Composite Systems
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 informationAlignment of Liquid Crystals by Ion Etched Grooved Glass Surfaces. Yea-Feng Lin, Ming-Chao Tsou, and Ru-Pin Pan
CHINESE JOURNAL OF PHYSICS VOL. 43, NO. 6 DECEMBER 2005 Alignment of Liquid Crystals by Ion Etched Grooved Glass Surfaces Yea-Feng Lin, Ming-Chao Tsou, and Ru-Pin Pan Department of Electrophysics, National
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 informationFast-Response Infrared Ferroelectric Liquid Crystal Phase Modulators
Mol. Cryst. Liq. Cryst., Vol. 453, pp. 343 354, 2006 Copyright # Taylor & Francis Group, LLC ISSN: 1542-1406 print=1563-5287 online DOI: 10.1080/15421400600653886 Fast-Response Infrared Ferroelectric Liquid
More informationPolymer-stabilized nanoparticle-enriched blue phase liquid crystals
Supporting Information for: Polymer-stabilized nanoparticle-enriched blue phase liquid crystals Ling Wang, a Wanli He, b Qian Wang, c Meina Yu, a Xia Xiao, d Yang Zhang, b Mujtaba Ellahi, b Dongyu Zhao,
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. Light Amplification by Stimulated Emission of Radiation
LASER Light Amplification by Stimulated Emission of Radiation Laser Fundamentals The light emitted from a laser is monochromatic, that is, it is of one color/wavelength. In contrast, ordinary white light
More informationRegistration of CBS Effects from Wedge-shaped Samples Containing Particles of Alumina
VII International Conference on Photonics and Information Optics Volume 2018 Conference Paper Registration of CBS Effects from Wedge-shaped Samples Containing Particles of Alumina Sh. M. ISMAILOV 1,2 and
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 informationQUESTION BANK IN PHYSICS
QUESTION BANK IN PHYSICS LASERS. Name some properties, which make laser light different from ordinary light. () {JUN 5. The output power of a given laser is mw and the emitted wavelength is 630nm. Calculate
More informationDevelopment, Features and Applications
Random LASERS Development, Features and Applications Hui Cao The random laser differs from other types of laser in that its cavity is formed not by mirrors but by multiple scattering in a disordered gain
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 informationLaser Types Two main types depending on time operation Continuous Wave (CW) Pulsed operation Pulsed is easier, CW more useful
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 informationPhotoresponsive Behavior of Photochromic Liquid-Crystalline Polymers
Photoresponsive Behavior of Photochromic Liquid-Crystalline Polymers Tomiki Ikeda Chemical Resources Laboratory, Tokyo Institute of Technology R1-11, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
More informationTransient Electro-Optic Properties of Liquid Crystal Gels
137 Appendix A Transient Electro-Optic Properties of Liquid Crystal Gels The dynamics of the electro-optic response has significance for the use of our gels in display devices and also reveals important
More informationHigh characteristic temperature of 1.3 #m crescent buried heterostructure laser diodes
Bull. Mater. Sci., Vol. 11, No. 4, December 1988, pp. 291 295. Printed in India. High characteristic temperature of 1.3 #m crescent buried heterostructure laser diodes Y K SU and T L CHEN Institute of
More information2008,, Jan 7 All-Paid US-Japan Winter School on New Functionalities in Glass. Controlling Light with Nonlinear Optical Glasses and Plasmonic Glasses
2008,, Jan 7 All-Paid US-Japan Winter School on New Functionalities in Glass Photonic Glass Controlling Light with Nonlinear Optical Glasses and Plasmonic Glasses Takumi FUJIWARA Tohoku University Department
More informationDirection controllable linearly polarized laser from a dye-doped cholesteric liquid crystal
Direction controllable linearly polarized laser from a dye-doped cholesteric liquid crystal Ying Zhou, Yuhua Huang, Tsung-Hsien Lin, Liang-Pin Chen, Qi Hong, and Shin-Tson Wu College of Optics and Photonics,
More informationDye-doped dual-frequency nematic cells as fast-switching polarization-independent shutters
Dye-doped dual-frequency nematic s as fast-switching polarization-independent shutters BING-XIANG LI, 1, RUI-LIN XIAO, 1, SATHYANARAYANA PALADUGU, 1 SERGIJ V. SHIYANOVSKII, 1 AND OLEG D. LAVRENTOVICH 1,,
More informationThis document is downloaded from DR-NTU, Nanyang Technological University Library, Singapore.
This document is downloaded from DR-NTU, Nanyang Technological University Library, Singapore. Title Polarization-independent electrically tunable/switchable airy beam based on polymer-stabilized blue phase
More informationMicrostructure of Reflection Holographic Grating Inscribed in. an Absorptive Azopolymer Film
Microstructure of Reflection Holographic Grating Inscribed in an Absorptive Azopolymer Film Hyunhee Choi Department of Physics, Soongsil University, Seoul 156-743, Korea Microstructure of reflection holographic
More informationDetermining the orientation of the emissive dipole moment associated with dye molecules in microcavity structures
journal of modern optics, 15 october 2004 vol. 51, no. 15, 2287 2295 Determining the orientation of the emissive dipole moment associated with dye molecules in microcavity structures S. H. GARRETT, J.
More informationElectrically switchable optical vortex generated by a computer-generated hologram recorded in polymer-dispersed liquid crystals
Electrically switchable optical vortex generated by a computer-generated hologram recorded in polymer-dispersed liquid crystals Y. J. Liu, X. W. Sun, * Q. Wang, and D. Luo School of Electrical and Electronic
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 informationRANDOM LASER IN DISORDERED SOLUTIONS
The Pennsylvania State University The Graduate School Department of Electrical Engineering RANDOM LASER IN DISORDERED SOLUTIONS A Thesis in Electrical Engineering by Rong Tang 2017 Rong Tang Submitted
More informationMulti-cycle THz pulse generation in poled lithium niobate crystals
Laser Focus World April 2005 issue (pp. 67-72). Multi-cycle THz pulse generation in poled lithium niobate crystals Yun-Shik Lee and Theodore B. Norris Yun-Shik Lee is an assistant professor of physics
More informationREAL-TIME SPECTROSCOPY OF SOLID-STATE RANDOM LASERS
REAL-TIME SPECTROSCOPY OF SOLID-STATE RANDOM LASERS J. FERNÁNDEZ*, S. GARCÍA-REVILLA, R. BALDA Dpto. Física Aplicada I, Escuela Superior de Ingenieros, Alda. Urquijo s/n 483 Bilbao, Spain Centro Física
More informationSupporting information. GaN Metalens for Pixel-Level Full-Color Routing at Visible Light
Supporting information GaN Metalens for Pixel-Level Full-Color Routing at Visible Light Bo Han Chen 1,, Pin Chieh Wu 2,, Vin-Cent Su 3,, Yi-Chieh Lai 1,4, Cheng Hung Chu 2, I Chen Lee 5, Jia-Wern Chen
More informationMulti-Purpose Nonlinear Optical Microscope. Principle and its Applications to Polar Thin Film Observation
Multi-Purpose Nonlinear Optical Microscope. Principle and its Applications to Polar Thin Film Observation Y. Uesu, N. Kato Department of Physics, Waseda University 3 4 1 Okubo, Shinjuku-ku, Tokyo 169-8555,
More informationUnbalanced lensless ghost imaging with thermal light
886 J. Opt. Soc. Am. A / Vol. 3, No. 4 / April 04 Gao et al. Unbalanced lensless ghost imaging with thermal light Lu Gao,,3 Xiao-long Liu, hiyuan heng, and Kaige Wang, * School of Science, China University
More information