Abstract

The ultrafast gain recovery dynamics [1] observed in quantum cascade lasers (QCLs) fundamentally restricts the formation of intracavity pulses. On the other hand, this picosecond gain response makes the QCL uniquely suited for microwave modulation of its pump current. Here, we leverage on this property and generate short optical pulses (~30 ps) with up to Watt level peak power. Lasing on a single longitudinal mode is achieved via optical injection seeding. We characterize the generated optical pulses in both frequency and time domain using a spectrometer in combination with an optical sampling method. The obtained results are interpreted in the framework of laser rate equations.

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