Intermodulation and Harmonic Distortion in Traveling-Wave Semiconductor Cascade Laser

Intermodulation distortion and harmonic distortion in a traveling-wave semiconductor cascade laser (TWSCL) is investigated. The TWSCL is an extension of the idea of a semiconductor cascade laser where transmission lines connect the laser diodes in a cascade followed by a terminating impedance. The nonlinear behavior of the TWSCL is analyzed using harmonic balance and determined to be comparable to a resistively matched laser diode. The analysis is further supported using a perturbative approach. Experimental results for a TWSCL using packaged devices are presented.