[OPTICAL REVIEW Vol. 7, No. 1 (2000) 73-82]

Dynamics of Optical Switching and Stability Analysis of a Polarization Bistable Laser Diode with Detuned External Light Injection

Bijan GHAFARY and Masakatsu OKADA

The Department of Photonics, Ritsumeikan University, 1-1-1, Noji-Higashi, Kusatsu, Shiga, 525-8577 Japan

(Received July 9, 1999; accepted October 14, 1999)

Dynamic behaviors of a polarization-bistable laser diode with detuned light injection are studied, including slow, fast and overshoot switching processes. Dependences of switching time of optical outputs between locked and free oscillating modes on the detuning and power of optical input, carrier injection rate and cross-gain saturation coefficients are investigated. Based on linear stability analysis the system stability is analyzed and analytical expressions are developed to predict the switching time. Our analytical results, in which the switching of optical output from locked to unlocked modes is shown to be composed of two relaxation processes with short and long time constants, are in agreement with the numerical results showing fast and slow switching behaviors dependent on the initial locked state, in contrast to the dynamic behavior of the carrier density dominated by a single relaxation process.

Key words : polarization-bistable laser diode, polarization switching, switching speed