Nonlinear optics spectroscopy in glasses doped with nanoparticles

Transcription

1 Nonlinear optics spectroscopy in glasses doped with nanoparticles Juliana Mara Pinto de Almeida 1, Luciana R. P. Kassab, Cleber R. Mendonça 1 and Leonardo De Boni 1 1 Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil Faculdade de Tecnologia de São Paulo - CEETEPS, São Paulo, SP, Brazil

2 Outline Motivation Background (Nonlinear Optics effect) Experimental setup (Z-Scan and WLCZ-Scan and Optical Kerr Gate) Experimental results Conclusion

3 Motivation Why study nonlinear effect in glasses with nanoparticles? Local field enhancement effect They are promising materials for photonic applications: ultrafast response times and high third order nonlinearities

4 Optical Limiters Motivation Find new materials with Multi-photon absorption Find new materials for telecom All-Optical Switches Excited state life time Saturable absorbers

5 Nonlinear Optics Nonlinear Polarization (transparent midium) P 1345 E (3) Im (5) Im (7) Im EE Nonlinear absorption h EEE 3 ( I) 0 I 3I 4I EEEE e' e g EEEEE... Multi-photon absorption

6 Nonlinear Optics introduction Nonlinear Polarization (transparent medium) P 1345 E EE EEE EEEE EEEEE... Optical Kerr effect (3) Re n( I) n0 n n0 ni (3) 3 4n c n Nonlinear refraction 0 Nonlinear medium r kn I( r) L Electronic effects

7 Experimental setup Laser System Ti:sapphire chirped pulse amplified system (CPA-001) 775 nm 150 fs 800 J Optical parametric amplifier (TOPAS) nm 10 fs 0-60 J

8 TOPAS Experimental setup Z-scan technique LASER CLARK Trigger Computador LabView Lock-in To obtain the spectrum of the nonlinear effect P ED ED L FE L P L S F ED I I D 1 T ln[1 q0( z,0) e ] q0( z,0) d q 0 ( z, t) I0( t) L 1 z / z 0 Sheik-Bahae, M. et al.., IEEE J. Quantum Elect. 1990, 6, De Boni L et al Optics Express, Opt. Express, 1, (004)

9 Z-scan Results Traditional Z-scan WLC Z-scan Typical (a) open- and (b) closed-aperture Z-scan curves obtained at several wavelengths. The solid lines represent fittings. The pulse energy and the beam waist used in the open aperture Z-scan are 34 nj and 16 μm for 500 nm, 9 nj and 17 μm for 550 nm, 7 nj and 18 μm for 600 nm, 3 nj and 19 μm for 650 nm, 19 nj and 0 μm for 700. The pulse energy and the beam waist used in the closed aperture Z-scan are 8 nj and 16 μm for 560 nm, 16 nj and 17μm for 650 nm, 16 nj and 18 μm for 750, 17 nj and 18.5 μm for 800 nm and 6 nj and 0 μm for 1300 nm. De Boni L et al Optics Express, 0, (01)

10 Absorbance Lead-germanium oxide glasses + Ag 59PbO-41GeO (in wt. %) for glass host (sample A) + AgNO 3 (5.0 wt. %) Annealed 40 C for 1 h (sample B) 480 C for 3 h (sample C) Filling factor of about % for sample C Sample A Sample B Sample C 1.0 SPR Wavelength (nm) The inset shows the image of Ag NPs investigated with a high resolution TEM De Boni L et al Optics Express, 0, (01)

11 Two-photon absorption spectra 1 T ln[1 q0( z,0) e ] d q0( z,0) I0( t) L q0( z, t) 1 z / z 0 Saturable absorption Two-photon absorption This increment is attributed to an interband transition in the Ag nanoparticles, also mediated by a PA excitation. Qu S. et al Opt. Mater. 8(3), (006). Enhancement effect De Boni L et al Optics Express, 0, (01)

12 Nonlinear refraction spectra De Boni L et al Optics Express, 0, (01) Transparent glass ceramic containing sodium niobate nanocrystals. Falcão-Filho E et al Phys. Rev. B 69(13), (004). Same value glass host 53 nm (ps) 1064 nm (ps) 800 nm (fs)

13 Optical limiting effect 0 is very small W> All-optical switch GOOD De Boni L et al Optics Express, 0, (01)

14 Tungsten Lead-Pyrophosphate + Cu 70Pb P O 7-30WO 3 (in wt. %) for glass host + CuO (0.5 wt. %) Changes in color (i) (ii) (iii) (iv) + SPR (a) Cu NPs investigated with a high resolution TEM (b) Crystallographic planes of cubic Cu structure NPs Manzani et al, Plasmonics, (013)

15 Nonlinear refraction and Absorption 1 T ln[1 q0( z,0) e ] q0( z,0) Nonlinear Absorption spectra d q 0 ( z, t) I0( t) L 1 z / z 0 Inversion of the effect Enhancement effect Manzani et al, Plasmonics, (013)

16 8 4 (b) DR19-CL tempo (ps) Outside of the Plasmon band 780 nm 00 fs Optical Kerr Gate effect FAST Topas ( nm) 10 fs ou 50 fs, ~1kHz ou íris ω e 3ω translação Clarck ou Dragon 150 fs ou 30 fs, ~775nm, 1kHz translação íris lente transmitância amplificador lock-in detector Inside of the Plasmon band 560 nm.3 ps SLOW Manzani et al, Plasmonics, (013)

17 Heavy metal oxide glasses + Au 58.4 GeO 41.6 Bi O 3 (in wt. %) for glass host + 3Au O 3 0.5Eu O 3 (wt%) Nonlinear Absorption spectra 1 T ln[1 q0( z,0) e ] q0( z,0) q 0 I0( t) L ( z, t) 1 z / z 0 d Inside of the Plasmon band Two-photon Absorption 500 nm Two-photon Absorption + Saturable absorption Manzani et al, Plasmonics, (013)

18 Heavy metal oxide glasses + Au 58.4 GeO 41.6 Bi O 3 (in wt. %) for glass host + 3Au O 3 0.5Eu O 3 (wt%) Nonlinear refraction spectra Outside of the Plasmon band 780 nm ~00 fs FAST Manzani et al, Plasmonics, (013)

19 Conclusion Saturable and two-photon absorption were observed plasmon band Increased because of an interband transition in the case of Ag nanoparticles Nonlinear refraction was observed to be the same 10 times higher than fused silica low filling factor Ag and Au Optical limiting effect was observed to increase a factor of due to the AgNP Samples can be used as optical limiters, all-optical switches and saturble absorbers because of the distinct response times FAST SLOW

20 Acknowledgements Thank you