Low-power-threshold photonic saturable absorber in nonlinear chalcogenide glass

Abstract : We experimentally demonstrate controllable nonlinear modulation of optical guiding in ultrafast laser-written evan- escently coupled waveguide arrays in bulk gallium lanthanum sulfide chalcogenide glass. The intensity-dependent response is validated by simulating light propagation in waveguide arrays with instantaneous Kerr nonlinearity using a discrete continuous spatiotemporal unidirectional Maxwell equation model. The intensity-driven modulation of transmission in multicore structures acts as a potential saturable absorber at kilowatt threshold levels