The results of an experimental investigation ol nonlinearities and bistability at the band gap in InAs are presented. Bistability was observed in reflection at 3 mW with a HF laser by using the large nonlinearity at the band-gap resonance in InAs. The measured nonlinear refractive index is shown quantitatively to agree with the dynamic Burstein—Moss shift as the mechanism, as long as both the full Fermi-Dirac statistics and the effect of light holes are included in the calculation. In a separate study a theoretical analysis has investigated general conditions for intrinsic bistability without cavities. It is shown that bistability can result from a nonlinear constitutive relation. Specific calculations are presented for bistability due to nonlinear polarization.
Single and multicast wavelength conversion at 40 Gb/s by means of fast nonlinear polarization switching in an SOA