PICOSECOND PULSE MEASUREMENTS USING THE ACTIVE LASER MEDIUM

A simple method for measuring the pulse lengths of synchronously pumped dye lasers has been developed which does not require the use of an external nonlinear medium, such as a doubling crystal or two-photon flourescence cell to autocorrelate the pulses. The technique involves feeding the laser pulses back into the dye jet, thus correlating the output pulses with the intracavity pulses to obtain pulse length signatures in the resulting time-averaged laser power. Experimental measurements were performed using a rhodamine 6G dye laser pumped by a modelocked frequency doubled Nd:YAG laser. These results agree well with numerical computations and the method proves effective in determining lengths of picosecond laser pulses. © 1990 IEEE