Measurement of the modulation efficiency of an optical phase modulator using a self-homodyne receiver

The authors describe a self-homodyne technique to measure the modulation efficiency of an optical phase modulator. The phase modulator is driven by a sine wave and the baseband spectrum is measured and analyzed. Combinations of the ratio of harmonics are used to estimate V/sub /spl pi// of a commercially available modulator with a resolution of 0.8%. The method offers simplicity because it uses a single laser, does not require sensitive optical adjustments, and lends itself to the measurement of V/sub /spl pi// as a function of modulation frequency and optical carrier wavelength.