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.
The static Transfer Matrix Method (TMM) and Multi-mode Rate Equations (MMRE) are combined together to simulate
dynamic characteristics of three section DBR lasers. Dynamic Side Mode Suppression (SMSR) is introduced to study
wavelength switching transients for the first time, along with the lasing spectrum characteristics.