Spectrally compensated third harmonic generation using angular dispersers

We investigate the effectiveness of the use of angular dispersers for the generation of third harmonic by the mixing of omega and 2 omega waves in nonlinear crystals. Unlike the case for the generation of second harmonic using an angular disperser in which the complete compensation of first order phase mismatch is possible, it is found that only a partial compensation of the first order phase mismatch is possible, in general, for the third harmonic. Nevertheless, we find that such a partial compensation of the phase mismatch could be very effective. Specific numerical results are also presented for the mixing of 800 nm and 400 nm waves using a beta-barium borate and a potassium dihydrogen phosphate crystals with type-I phase matching geometry. (C) 1999 Elsevier Science B.V. All rights reserved.