A 12-pass laser amplifier scheme for achieving efficient high gain amplification

Summary form only given.If one wishes to extract energy from an amplifier one usually requires substantial input energies, and the net gain is modest. Gain and energy extraction can be improved by double passing an amplifier system, often using nonlinear optical phase conjugation to compensate for aberrations. In amplifier systems it is often convenient to use relay imaging, using an intermediate telescope. In this paper we introduce an optical element to intercept beams propagating in a self-imaging system and introduce an angle multiplexing arrangement. This makes it possible to pass a beam through an amplifier many times. The technique is generic and applicable to a variety of laser amplifiers.