FIELD: optical instrument engineering. SUBSTANCE: pumping radiation in the form of fundamental solutions or pulses similar to them in amplitude, and signal radiation with variable intensity and/or phase are applied to the input of a nonlinear double-beam refracting light pipe possessing the second-order dispersion, polarizations of radiations are mutually orthogonal, and polarization of one of the radiations is directed along the "fast" or "slow" axis of the light pipe, or at an angle to this axis not exceeding π/10. EFFECT: enhanced gain. 9 cl, 3 dwg
