Observation of Low Chirp Modulation in Long Wavelength InGaAs/InAlAs Multiple-Quantum-Well Optical Modulators

Abstract
Modulated light spectra are measured in long-wavelength InGaAs/InAlAs multiple-quantum-well intensity modulators under 990 MHz, large signal modulation. The linewidth broadening factor, α, is determined from the relation between the intensity modulation index and the sideband strength, relative to the carrier. The minimum α value is estimated to be 0.60, which is less than that reported in a bulk Franz-Keldysh modulator.