TECHNIQUE FOR EVALUATING 2ND-ORDER NONLINEAR-OPTICAL MATERIALS IN POWDER FORM

A technique for evaluating second-order nonlinear optical materials in powder form is described. The power of the second-harmonic wave gener ated with the evanescent wave (SHEW) loosely depends on the phase matc hability of material. The largest element of the nonlinear optical coe fficient can be estimated from the SHEW power, regardless of the phase matchability of the material in a bulk crystal, even when powder crys tals are used as the sample. The sample setting condition that gives a ppropriate repeatability is obtained, and the accuracy of this measure ment is also discussed. Several well-known materials are measured usin g this technique, and the results are compared with other works.