OPTICAL PHASE CONJUGATION APPARATUS INCLUDING LIGHT PIPE FOR MULTIPLE BEAM COMBINATION

• Main Author: STEPHENS; RONALD R
• Format: Patent
• Language: English
• Published: 22.10.1991
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DEVICES USING STIMULATED EMISSION; ELECTRICITY; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

A rectangular light pipe (38) and associated optical elements (36, 40) are used to produce an overlapped combination of an array of aberrated laser beams (32, 34) inside a phase conjugate mirror (42). The beam array (32, 34) is focussed onto the entrance face (38a) of the light pipe (38) in such a way that each beam (32, 34) spreads by diffraction and internal reflections to fill the exit face (38b) of the light pipe (38). An image of the exit face (38b), which is completely filled by the overlapped beams (32, 34), is focussed into the phase conjugate mirror (42) such as to produce an overlap spot (46) size which is independent of beam aberration level. The apparatus preserves the linear polarization of the input beams (32, 34), has low optical loss, and may be incorporated into a two-pass or four-pass phase conjugate master-oscillator power amplifier.