WIDE OPTICAL BANDWIDTH ASYMMETRIC FABRY-PEROT REFLECTION MODULATOR USING THE QUANTUM-CONFINED STARK-EFFECT

A normally on, high-performance quantum confined Stark effect asymmetr ic Fabry-Perot reflection modulator with enhanced optical bandwidth is reported. The wide optical bandwidth is achieved by utilizing the var iation in refractive index in the vicinity of the heavy-hole exciton. The nominal operating wavelength is set in the region where the on-sta te refractive index starts to increase and allows the Fabry-Perot reso nance condition to be maintained over a wide wavelength range. An opti cal bandwidth of 5 nm is achieved for an operating voltage of 7 V, ins ertion loss <2.5 dB, reflectance change >55% and contrast ratio > 15 d B, and 7 nm if the contrast ratio is relaxed to >10 dB. These values a re twice as wide as previously reported for a quantum confined Stark e ffect modulator structure, and correspond to an operating temperature range of 25 degrees C compared to 10 degrees C for conventional struct ures. (C) 1998 American Institute of Physics. [S0021-8979(98)01022-6]