OPTICAL BANDWIDTH CONSIDERATIONS IN P-I-N MULTIPLE-QUANTUM-WELL MODULATORS

We investigate the optical bandwidth of p-i(multiple quantum well [MQW ])-n modulators employing various MQW designs. The optical bandwidth t ranslates directly into an operating temperature range due to the shif t of the band gap with temperature. We find that although greater maxi mum modulation may be obtained with narrow (similar to 90 Angstrom) qu antum wells operating below the band edge (absorption increases with f ield), uniform large performance may be obtained over a larger bandwid th using wider (similar to 110 Angstrom) quantum wells operating at th e exciton (absorption decreases with field). We obtain a usable bandwi dth of 7.7 nm, which translates into a operating temperature range of 27 degrees C.