Nonlinear InGaAs-InGaAsP single-quantum-well all-optical switch - theory and experiments

A single-mode Fabry-Perot guided wave resonator, containing a single quantum well of InGaAs embedded in an InGaAsP-InP waveguide, facilitates the theoretical and experimental study of semiconductor all-optical nonlinear dichroic (SAND) devices. The dichroism generated by absorption edge selection rules for the quantum well governs the switching mechanism. It leads to two separate bandedges for TE and TM polarized light and real excitation refractive nonlinearities. The SAND device shows a signal gain of over 2 and a modulation depth of about 54%.