Theory of energy gain in a laser-amplifier based on a photon-branched chain reaction: Auto-wave amplification mode under the condition of input signal focusing

Abstract

Huge energy gain is detected theoretically in a pulsed chemical laser amplifier based on a photon-branched chain reaction initiating in a gaseous disperse medium composed of H2-F2-O2-He and Al particles by focused external infrared radiation. It is shown that this effect is observed due to the possibility of the ignition of the laser–chemical reaction into an initial small focal volume of an active medium. It then spreads out of this minimal volume spontaneously in the auto-wave regime without external power sources and subsequently fills the whole volume of the laser cavity with a high intensive electromagnetic field as self-supporting cylindrical photon-branching zones formed by the paths of the rays inside the unstable telescopic cavity. Calculations show that the ignition of an auto-wave photon-branched chain reaction under the condition of external signal focusing strongly reduces the input pulse energy necessary for initiation up to ∼10−8 J, and thereby allows a huge value of the energy gain of ∼1011. The observed effect of this huge laser energy gain makes it possible to construct a self-contained laser with kilojoule output energy, which can be initiated by a very weak source signal.