Frequency modulation characteristics of coupled stripe laser diode array

Time-dependent changes in the cavity resonance frequency were measured in a ten-element gain-guided coupled stripe array using a new technique based on injection locking. Sensitivity of the frequency to changes in the array current was 0.7 GHz/mA at dc and 0.04 GHz/mA for 1.0 MHz sine-wave modulation. The current-to-frequency modulation transfer function for the array was determined, and it was concluded that the transition from thermal to carrier-induced frequency modulation occurs in the region between 10
⁵
and 10
⁶
Hz.