Microwave frequency operation of a low-voltage InGaAs/InP multiple-quantum-well reflective Fabry-Perot modulator

Useful modulation at frequencies in excess of 1.3 GHz has been achieved in a long-wavelength InGaAs/InP multiple-quantum-well reflective modulator. Microwave frequency operation of the modulator was investigated using a free-space link, is shown schematically. The modulator was illuminated with focussed radiation from a Fabry-Perot laser emitting close to the 1610 nm resonance, use of a polarisation-selective beam splitter in conjunction with a quarter-wave retarder providing efficient resolution of power reflected from the device in the presence of stray power from other system components. RF drive to the modulator via a bias network permitted investigation of behaviour under a variety of bias conditions. Reflected modulated power was detected using a reverse biased pin photodiode, again coupled via a bias network