Phase conjugation allows us to simplify the optics drastically (the quality of optical elements and the accuracy of alignment), as well as to simplify demands to the optical medium along the beam. The most suitable scheme for the phase conjugation is the two-pass scheme. As regards the L-SPS experiment and the SPS problem as a whole, phase conjugation allows us to suggest the following key scheme: an on-board laser must be designed as a two-pass amplifier with a PCM to provide the second pass laser beam to be amplified. The ground-based system must include a master laser with forming optics as a source of a weak reference beam. The mutual alignment of a master laser and an on-board amplifier is produced by the usual optics and optoelectronics. Due to receiving a part of the reference-beam the on-board system has the following capabilities: 1) Automatic and high-precision forming of high-power laser radiation towards the ground-based converter; 2) Diffraction-limited compensation of optical defects and disalignment of the amplifier due to properties of PCM's 3) Diffraction-limited phasing of an on-board optical system is also due to properties of PCM's in a two-pass scheme. It is interesting to describe our experimental results in the phase conjugation field. These results concern two main branches: utilizing PCM's for the new generation of lasers and investigation of the possibility of achieving diffraction limited laser beams with a remote laser “request” by a weak reference beam. It is evident that an on-board laser will be multi-channel, and the output beam must be phased as a whole. We designed and produced a one-channel solidstate laser with a PCM and diffraction-limited output beam as an industrial device about ten years ago. It was an example of a possibility for compensating optical defects and disalignments. The efficiency of this laser is approximately the same as the efficiency of usual solid-state lasers on this level with large divergenceance without PCM. Other lasers have been designed with PCM, which operates in long-time millisecond regime (this regime is very close to a quasi-continuous-wave regime of a high output power for a future, large-scale laser facility). Effective reflection and phase conjugation of millisecond pulses has been achieved. The phasing of multi-channel apertures has been investigated in two quite different experimental situations. A model of multi-channel laser phasing consists of a two pass large aperture laser amplifier and a close group of hexagonal optical elements with flat optical surfaces, which were inserted into the optical cross-section of the amplifier. The length and width of these elements were accidentally distributed between wide limits.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==