Analytical study of optical bistability in silicon-waveguide resonators.
We present a theoretical model that describes accurately the nonlinear phenomenon of optical bistability in silicon-waveguide resonators but remains amenable to analytical results. Using this model, we derive a transcendental equation governing the intensity of a continuous wave transmitted through a Fabry-Perot resonator formed using a silicon-on-insulator waveguide. This equation reveals a dual role of free carriers in the formation of optical bistability in silicon. First, it shows that free-carrier absorption results in a saturation of the transmitted intensity. Second, the free-carrier dispersion and the thermo-optic effect may introduce phase shifts far exceeding those resulting from the Kerr effect alone, thus enabling one to achieve optical bistability in ultrashort resonators that are only a few micrometers long. Bistability can occur even when waveguide facets are not coated because natural reflectivity of the silicon- r interface can provide sufficient feedback. We find that it is possible to control the input-output characteristics of silicon-based resonators by changing the free-carrier lifetime using a reverse-biased p-n junction. We show theoretically that such a technique is suitable for realization of electronically assisted optical switching at a fixed input power and it may lead to silicon-based, nanometer-size, optical memories.
Rukhlenko
Ivan D
ID
Department of Electrical and Computer Systems Engineering, Monash University, Melbourne, VIC, Australia. ivan.rukhlenko@eng.monash.edu.au
Premaratne
Malin
M
Agrawal
Govind P
GP
D000388:Air; D000465:Algorithms; D004867:Equipment Design; D006358:Hot Temperature; D008422:Materials Testing; D017711:Nonlinear Dynamics; D055096:Optical Devices; D055095:Optics and Photonics; D012825:Silicon / Q000737:chemistry*; D013696:Temperature
D012825:Silicon