A comparison of active and passive optical bistability in semiconductors

A comparison is presented between optical bistability in laser amplifiers and in passive Fabry-Perot cavities. The basis for comparison is afforded by a new analysis of optical amplifiers which encompasses the cases of passive refractive and absorptive bistability as special limiting cases. The results indicate that amplifiers have advantages of lower input intensity requirements (by a factor of 10³) and reduced sensitivity to wavelength by comparison with passive cavities; experimental results indicate an input power of -30 dBm is required for active bistability. Facet coating requirements for active and passive optimum configurations are also discussed.