High Accuracy Measurement of Relaxation Oscillation Frequency in Heavily Damped Quantum Well Lasers

The frequency of relaxation oscillations in a heavily damped quantum well laser, as a function of injection current, have been measured with an accuracy as good as 0.3% using a new method involving averaging of many, real-time, individual, relaxation oscillation events. This accuracy represents at least a six fold improvement compared to that obtained by the standard RF spectral analysis method applied to the same system. This accuracy enables critical comparison of experimental results with standard theory and suggests systematic variation of the experimental values from expected theory. This motivates further developments in the theory of relaxation oscillations in quantum well semiconductor lasers.