Nonlinear optical waveguides in As_2S_3-Ag_2S chalcogenide glass thin films

Abstract

Chalcogenide glasses (ChGs) are promising materials for nonlinear optical applications due to their elevated third-order optical susceptibility. Nonetheless, oxidation and photorefractive effects make the characterization and processing of this class of materials an intricate process. Employing ultrashort laser pulses, we were able to investigate the optical nonlinearities of As 2 S 3 thin films doped with Ag 2 S nanocrystals, as well as produce channel waveguides. The results showed that the nonlinear refractive indexes of these films are in the order of 2.3-5.2 x 10 −18 m 2 /W at wavelengths in the range of 775-1600 nm. Such film revealed to be proper for the development of nonlinear optical devices, since we have demonstrated the functionality of an 8.7 mm long waveguide for spectral broadening femtosecond IR pulses.

Optical Nonlinearities in Glasses

“…On the other hand, a relationship between the material band gap and the n 2 was also established. For example, the n 2 value obtained for pure As 2 S 3 was about 2.9 x 10 À18 m 2 /W while for fused SiO 2 was about 2.8 x 10 À19 m 2 /W [25], which is comparatively about 10 times lower. So, materials with lower band gap seam to exhibit an increase in the nonlinear optical behavior; SiO 2 has a gap of about 9 eV while that of As 2 S 3 is 2.3 eV [19].…”

Ultrafast Laser Pulses for Structuring Materials at Micro/Nano Scale: From Waveguides to Superhydrophobic Surfaces

“…However, not only bulk chalcogenide glasses have been exploited for waveguides devoted to mid-IR region, but also chalcogenide thin films, in which bidimensional curved waveguides have been performed by fs-laser micromachining. These materials demonstrated significant spectral broadening [120], thereby assuring their potential for nonlinear optics and new infrared technologies.…”

Solution phase driven As2S3 chalcogenide films: Optical and picosecond nonlinear optical properties

“…The n 2 value for As 2 S 3 solution driven¯lm and thermally deposited¯lm was found similar to the results obtained by other researchers. 20,22,38 It was observed that both the¯lms exhibited strong TPA but the thermally deposited¯lms demonstrated higher nonlinear absorption coe±cient than solution driven¯lm. This data indicates that these materials are well suited for applications such as all optical limiting and adaptive pulse shaping.…”

“…19 Arsenic tri-sul¯de (As 2 S 3 ) possesses easy synthesis route and also has an excellent photosensitivity. 20 In this paper, we demonstrate solution processed As 2 S 3 chalcogenide¯lms as an alternative route for¯lm deposition. The deposited¯lms were characterized for structural and chemical homogeneity to quantify the developed lms.…”