NONLINEAR OPTICAL ISOLATORS BASED ON HIGH-REFLECTIVITY BRILLOUIN MIRRORS AND THEIR APPLICATION TO ADVANCED LASERS

A new type of optical isolator, the nonlinear isolator (NLI), was developed to replace polarization sensitive isolation devices in pulsed, solid state laser systems. The NLI was based on a high-reflectivity, stimulated Brillouin scatter (SBS) mirror configured as a Newtonian telescope. Transmission through the NLI was found to be limited to the SBS threshold power. Input powers tested were 50 to 100 times the threshold power. The NLI was operated in a 10-Hz repetition rate laser without introducing noticeable far-field distortion. Partial pulse compression could occur in the NLI. A single triple-pass phase-conjugated YAG amplifier that incorporated the NLI, plus a 2-mJ SLM oscillator, produced 0.83-J pulses of 2.5-ns duration.