Second-harmonic generation in UV-pulsed laser poled amorphous 80GeS₂-15Ga₂S₃-5CdS chalcogenide film

Abstract

With the pulsed laser deposition (PLD) method, amorphous 80GeS₂-15Ga₂S₃-5CdS chalcogenide film was deposited on glassy substrate. Obvious second harmonic generation (SHG) was observed in the ultraviolet (UV)-polarized film and the SHG intensity increased with the increase in single pulse energy and irradiation time. Through Raman spectra and transmission spectra, the mechanism of SHG was studied. The experimental results demonstrated that effective electron traps and hole traps were generated in the UV-polarized film. The energy of electrons and holes was using up due to the collision with other particles and crystal fields during their movement and finally they were captured by the traps and fixed, which made the electric charge distribution nonuniform in the film and destroyed the spatial isotropy. In the meantime, the center of positive and negative charges separated and a built-in electric field was formed which generated the optical second-order nonlinearity of the film.

Keywords

amorphous GeS₂-Ga₂S₃-CdS chalcogenide film / UV-pulsed laser poled / second harmonic generation / maker fringes

References

[1] Aitken B, Newhouse MA Ga- and/or In-containing AsGe Sulphide Glasses[P], 1995, 5: 389

[2] Guignard M, Nazabal V, Troles J, . Second-harmonic Generation of Thermally Poled Chalcogenide Glass[J]. Opt. Express, 2005, 13(3): 789-794.

[3] Lin C, Tao H, Pan R, . Permanent Secondharmonic Generation in AgGaGeS4 Bulk-crystallized Chalcogenide Glasses [J]. Chem. Phy. Lett., 2008, 460: 125-128.

[4] GU S, MA Z, PAN R, . Structure and Properties of GeS₂-Ga₂S₃-CdS Amorphous Films Prepared by Pulsed Laser Deposition [J]. Journal of the Chinese Ceramic Society, 2008, 36(12): 1 725-1 729.

[5] Opt. Lett., 2001, 26(12

[6] Stolen RH, Tom HWK Self-organized Phase-matched Harmonic Generation in Optical Fibers [J]. Opt. Lett., 1987, 12: 585

[7] Anderson DZ, Mizrahi V, Sipe JE Model for Second-harmonic Generation in Glass Optical Fibers Based on Asymmetric Photoelectron Emission from Defect sites [J]. Opt. Lett., 1991, 16: 796

[8] Lawandy NM Intensity Dependence of Optically Encoded Secondharmonic Generation in Germanosilicate Glass: Evidence for a Light-Induced Delocalization Transition[J]. Phys. Rev. Lett., 1990, 65: 1745

[9] Nakane Y, Nasu H, Heo J, . Second Harmonic Generation from Thermally Poled Ge-S Glasses System [J]. Ceram. Soc. Jpn., 2004, 113: 728-732.