New method of measuring second harmonic generation efficiency using powder crystals

Abstract
A new method of measuring second-harmonic generation (SHG) efficiency using powder crystals is proposed. The second harmonic, which is generated by the evanescent wave under total reflection conditions, is phase matched for every element of the second-order optical nonlinear coefficient, whether each element is phase matchable in a bulk crystal or not. Observing this phase-matched second-harmonic power gives the SHG efficiency, regardless of the phase matchability in a bulk crystal, even if powder crystals are used as a sample.