We proposed a novel coherent delayed self-heterodyne technique for laser phase noise measurement. Measurements have been performed for DFB and ECL lasers and compared to self-homodyne using optical coherent receiver to demonstrate the validity of the technique.
We present coherent phase modulation detection for laser phase noise measurement via a
self-heterodyne technique. Measurements have been performed for DFB and SGDBR lasers to
demonstrate the technique. The results show that DFB laser phase noise is well described by the
random-walk phase fluctuation while SGDBR has additional frequency fluctuation due to 1/f noise
below 100 MHz that significantly broadens the linewidth.