Optimal Operation Point for the Primary Harmonic Content of a Modulated Laser Diode

An analysis of harmonic contents of the optical output power for a laser diode is performed, and the results are described in details. The influence of external parameters such as modulation current, bias current, and frequency on the absolute value of power for each harmonic are fully described. The analysis is done by direct solution of rate equations of an arbitrary laser diode for carrier and photon densities. It is shown that the optical power has a nonlinear dependence on modulation frequency, and the maximum optical power of each harmonic attained in its resonance frequency. The resonant frequency is shown to be tunable by bias current; thus in the next step we obtain the power for different harmonic contents, allowing better optimization to gain improved results. We calculate the higher relaxation resonant frequencies, and obtain their relation with respect to lower resonant frequencies. We extend our approach and find an optimal operation point in which the optimum characteristics of laser diode can be achieved. The sequence for every arbitrary laser structure is also possible to be developed by the approach presented in this work.