Reverse-Biased Gallium Phosphide Diodes as High-Frequency Light Modulators

Publisher Website
Google Scholar
Abstract
Reverse‐biased gallium phosphide diodes have been successfully operated as high‐frequency intensity and phase modulators of light at room temperature. The high‐frequency modulation is fundamentally limited by the series resistance and the capacitance of the diodes. Cutoff frequencies as high as 7 GHz have been measured. Diode capacitance, typically less than 7 pF at the operating point, and driver impedance determine the broad‐band characteristic. Intensity modulation measurements have been performed up to 500 MHz. The power consumption per MHz bandwidth for 40% intensity modulation was 2.7 mW for a diode only 0.7 mm long. A diode of 1.5 mm length used as a phase modulator needed only 1.5 mW of power per MHz bandwidth for a modulation index of 1 rad at a wavelength of 0.633 μ. This latter value corresponds to an intensity modulation depth of over 80%.

This publication has 11 references indexed in Scilit: