Abstract

Second harmonic generation (SHG) with multimode fundamental optical beams is investigated experimentally. The fundamental beam is derived from a laser oscillating simultaneously in many longitudinal modes that have the same transverse profile (TEM₀₀). The fundamental beam from the laser is optimally focussed into a nonlinear crystal. Noncritical Type-I phase matching is utilized to generate a second harmonic signal. The number of longitudinal modes in the laser is varied systematically from one to seven, and the dependence of the second harmonic signal on the number of modes in the fundamental beam is studied. In all cases the total fundamental intensity is held constant. Experimental results will be discussed and compared with theoretical models.

© 1992 Optical Society of America