SWITCHING CHARACTERISTICS OF NONBIASED OPTICAL BISTABILITY IN ASYMMETRIC FABRY-PEROT S-SEEDS MADE OF EXTREMELY SHALLOW QUANTUM-WELL STRUCTURES

The asymmetric Fabry-Perot (AFP) cavity structure extremely shallow qu antum wells (ESQWs) symmetric self-electro-optic effect device (S-SEED ) shows nonbiased optical bistability. We analytically investigated th e switching characteristics of the AFP ESQWs S-SEED (AE-SEED) using an impulse photocurrent response function and the corresponding voltage transients of the two p-i(ESQWs)-n diodes in AE-SEED. The result was c ompared to the characteristics of the conventional anti-reflection coa ted ESQWs S-SEED (E-SEED) with external bias. The large optical field and the thin intrinsic region in AE-SEED reduce the required incident switching energy and operating voltage, respectively. According to our analysis, the switching energy of an impedance-matched AE-SEED is 1.2 fJ mu m(-2), while that of an E-SEED is 4.1 fJ mu m(-2). With a reaso nable RC time constant and device size, the switching time of the AE-S EED is 11 ps while that of E-SEED is 12.4 ps for the minimum switching energy of each device.