Extreme Chirped Pulse Oscillator (Xcpo) Using A Theta Cavity Design

We demonstrate an extreme chirped pulse mode-locked laser, simultaneously generating near-transform-limited 3.9-ps optical pulses and ∼510-ps linearly chirped output from the oscillator. The design overcomes fundamental limitations of energy extraction and nonlinearities induced by gain dynamics so that we can increase the dc current of the semiconductor optical amplifier up to 600 mA without distortion of the pulse characteristics. The maximum average power of the stretched pulses from the 1.95-GHz harmonically mode-locked semiconductor laser is measured to be 13.4 mW at 600 mA. © 2006 IEEE