We explore LIDT test issues of the previous section using BBHR coatings that we described in Sec. 1 for 45-deg AOI and Ppol. The fs pulses of interest to us have a center wavelength of 900 nm with spectra extending from 800 to 1000 nm; as we have explained in Sec. 1, our coating design was guided by achieving and low GDD for 45-deg AOI, Ppol over the spectral range of 800 to 1000 nm, in keeping with standard BBHR requirements. The coatings consisted of layer pairs produced by e-beam evaporation with IAD in Sandia’s large optics coating chamber.6,7 For the layers, we used an back pressure in the chamber and reactively evaporated Ti metal. The details of the deposition process, the choice of and as the low and high index layer materials, respectively, and the BBHR design process appear in our earlier report.4 Here, we mention that we chose for the low index layer material because of its refractive index, at , that is one of the lowest among transparent oxides, and its high, , band-gap that makes it resistant to laser damage. We needed a high index layer material of very high refractive index to achieve an index contrast ratio with high enough to meet the demanding reflectivity requirement of from 800 to 1000 nm. The drawback is that high index dielectric materials have low band-gaps, which are not favorable to high LIDTs. We chose for the high index layers despite its low, , band-gap because its high refractive index, at , affords an index contrast ratio with that is high enough to meet the design requirements for the HR band. Our BBHR coating design softens the deleterious LIDT effects of the low band-gap layers in that the peak intensities of the standing wave E-fields across the broad HR band are lower at the layers than they are at the high band-gap layers. The design was optimized by starting from quarter-wave layer thicknesses in a reverse chirped arrangement to meet the HR requirements while maintaining low GDD. It features a thick () outer layer of . Again, more details of the design and deposition processes appear in our other report,4 which also presents the results of a white light interferometric measurement of the initial BBHR coating’s GDD. As we mentioned in Sec. 1, this GDD data exhibit low values with smooth behavior over the coating’s HR band, appropriate for preserving the temporal profile of fs pulses on reflection.