COMPARISON OF COLLINEAR AND ONE-BEAM NONCRITICAL NONCOLLINEAR PHASE MATCHING IN OPTICAL PARAMETRIC AMPLIFICATION

Optical parametric amplification in type I collinear and one-beam noncritical noncollinear phase-matching (PM) configurations has been investigated. The effects of absorption and walk-off of the interacting beams are fully taken into account, while their divergence, as well as the depletion of the pump, is assumed to be negligible. Numerical results with the organic crystal 3-methyl-4-nitropyridine-1-oxide show that, when the crystal thickness exceeds a certain value, one-beam noncritical noncollinear PM is more efficient than collinear PM owing to the different geometry of the interacting beams. Thus the applications of one-beam noncritical noncollinear type I PM in optical parametric amplification and oscillation experiments are expected to be even more interesting when the beams are focused.