Diffraction gratings utilizing total internal reflection facets in Littrow configuration

The shape of the grooves of a diffraction grating can be designed to take advantage of total internal reflection. We demonstrate the effectiveness of the total internal reflection (TIR) grating numerically for the bulk optic case. The results indicate that the efficiency of the retrodiffracted order is enhanced by as much as 11 dB when the TIR grating design is used in place of a blazed grating with no facet metallization.