Optical Nonlinear Susceptibilities: Accurate Relative Values for Quartz, Ammonium Dihydrogen Phosphate, and Potassium Dihydrogen Phosphate

A complete theoretical and experimental analysis of the Maker fringes leads to the determination of accurate relative nonlinear optical susceptibilities in Si${\mathrm{O}}_{2}$, ${\mathrm{NH}}_{4}$${\mathrm{H}}_{2}$P${\mathrm{O}}_{4}$, and K${\mathrm{H}}_{2}$P${\mathrm{O}}_{4}$: ${{d}_{11}}^{2\ensuremath{\omega}}(\mathrm{Si}{\mathrm{O}}_{2})=(0.77\ifmmode\pm\else\textpm\fi{}0.04) {{d}_{36}}^{2\ensuremath{\omega}}(\mathrm{K}{\mathrm{H}}_{2}\mathrm{P}{\mathrm{O}}_{4})$; ${{d}_{36}}^{2\ensuremath{\omega}}(\mathrm{N}{\mathrm{H}}_{4}{\mathrm{H}}_{2}\mathrm{P}{\mathrm{O}}_{4})=(1.21\ifmmode\pm\else\textpm\fi{}0.05){{d}_{36}}^{2\ensuremath{\omega}}(\mathrm{K}{\mathrm{H}}_{2}\mathrm{P}{\mathrm{O}}_{4})$, for a fundamental wavelength 1.064 \ensuremath{\mu}m. Application of this analysis to earlier data leads to corrected values in good agreement with the present study, thereby establishing these materials as accurate and reliable standards for measurement of nonlinear optical susceptibilities.