Abstract

One fundamental problem with current laser sources is that while the mechanisms that produce amplification by stimulated emission may be modified by a variety of means to produce laser pulses of different pulse lengths, this is of course specific to the laser in question, and in most cases there is an upper and lower limit that may be achieved. The upper limit to pulse length is for several laser sources continuous wave (CW) operation. The lower limit is often determined by the stability of the lasing state and several other factors, such as pumping scheme, Q-switching, etc. However, as is most often the case, if a specific pulse length is desired, a specific configuration of the laser system may be developed to meet that need. Then normally only the desired pulse length can be obtained. Nonlinear pulse shortening (NLPS) was discovered in the early 1970s and has been discussed by various workers.^1–3 This technique utilizes the property of stimulated Brillouin scattering (SBS) and/or stimulated Raman scattering (SRS) to shorten pulses. Pulse lengths in the 100-psec region at 2 mJ per pulse have been created utilizing SBS and 1 psec utilizing SRS, which produces a rather large wavelength shift. These processes have been shown to be successful for a variety of laser systems operating at a variety of wavelengths. In this paper we discuss a method specifically using a Nd:YAG laser which is operating at wavelengths in the vicinity of 1.06 μm.

© 1994 IEEE