Nonlinear refractive index of ultrafast laser inscribed waveguides in gallium lanthanum sulphide

Abstract

We demonstrate ultrafast all-optical switching in femtosecond laser inscribed nonlinear directional couplers in gallium lanthanum sulphide operated at 1.55 μm. We report on the evaluation of the nonlinear refractive index of the waveguides forming the directional couplers by making use of the switching parameters. The nonlinear refractive index is reduced by the inscription process to about 4-5 times compared to bulk material.

Photonic circuits written by femtosecond laser in glass: improved fabrication and recent progress in photonic devices

“…6(f). 69,70,[73][74][75][76] This technique does not depend on the intensity distribution at the focal volume and enables WG fabrication with desirable morphologies, such as square cross-sections along with a step index refractive index profile [ Fig. 6(g…”

Ge22As20Se58 glass ultrafast laser inscribed waveguides for mid-IR integrated optics

“…For this work we utilize Ultrafast Laser Inscription (ULI) as our fabrication method as it is an established technique for producing channel waveguides in transparent dielectrics that can be used to create complex integrated optics devices such as photonic lanterns, couplers and fanouts [12][13][14]. In comparison with planar fabrication techniques used to create chalcogenide channel waveguides for integrated optics, for instance photolithography and etching [9] or lift-off techniques [15], ULI has many advantages, such as three dimensional design freedom, the possibility for rapid prototyping and single step fabrication.…”

Laser inscribed optical waveguides in emerging photonic material platforms

“…Direct laser inscription in chalcogenides has enabled ultrafast all-optical switches due to an easily-induced nonlinear Kerr effect coming from a high third order nonlinear susceptibility in these substrates [53]. Also, super continuum generation and spectral broadening have been demonstrated in direct laser-written waveguides in chalcogenide glasses [54][55][56].…”