Measurement of picosecond semiconductor laser pulse duration with internally generated second harmonic emission

Abstract

We demonstrate a simple practical technique for the measurement of the duration of picosecond semiconductor laser pulses using the internally generated second harmonic emission accompanying the laser output. The pulse duration is determined by the ratio of the conversion efficiencies of the second harmonic emission generated by the picosecond pulses and by the cw emission or other pulsed emission whose duration can be accurately measured. The pulse duration thus measured is in close agreement with that determined by the nonlinear intensity autocorrelation technique.