Nonlinear chirp compensation in high-power broad-spectrum pulses from single-stripe mode-locked laser diodes

We report on the generation of ultra-short high-energy pulses from extended-cavity mode-locked laser diodes by using single-stripe AlGaAs laser devices of long cavity length (1 and 2 mm). The pulse energy is shown to increase with the laser diode length while the spectral width of emitted pulses is decreased in the same time. Record pulse energies of ≈50 pJ are obtained from 2 mm long lasers and super-broad mode-locked spectra of ≈20 mm are achieved with 1 mm long lasers. Strongly nonlinear chirps are always observed in the case of mode-locked pulses whose spectral width exceeds 10 mm. After quadratic chirp compensation, 160 fs pulses are obtained with peak power larger than 100 W. These performances are believed to be the best ever reported for mode-locked single-stripe laser diodes without external amplification