Optical Pulse Compression

Abstract

The utilization of single-mode optical fibers as the nonlinear element in a pulse compression system has overcome several technical difficulties which have prevented the general use of pulse compression as a laboratory technique. The optical fiber based pulse compressor is particularly well matched to c.w. mode-locked lasers. For example, the 6 psec output pulses from a synchronously pumped, mode-locked, cavity-dumped, dye laser have been compressed to 90 fsec pulses. The peak intensity of the compressed pulses increased by 5 times and the wavelength was tunable. This compression method has also been used to compress the output pulses from the mode-locked ion laser and the frequency doubled pulses from a c.w. mode-locked Nd:YAG laser. In addition, the optical-fiber pulse compressor is especially well suited to compressing the ultra-short pulses from the colliding pulse mode-locked ring laser. This is mainly due to the large bandwidth of the optical compressor compared to the laser. However, for these ultrashort pulse applications the output power of the CPM laser is only barely adequate for pulse compression. Without any amplification, we have been able to compress the 110 fsec output pulses from our CPM laser to 55 fsec. By amplifying the CPM pulses, Shank et al have compressed their 90 fsec pulses to 30 fsec, the shortest pulses obtained to date. This is not a fundamental limit and shorter pulsewidths should be possible. The unique features of the pulse compressor will be described and the current status and accomplishments will be presented.