Temperature variation of the refractive indices of yttrium lithium fluoride

The temperature variations of the refractive indices of LiYF4, YLF, have been measured in the visible region of the spectrum. The temperature variation at 0.546 μm are −0.67×10−6/°C and −2.30×10−6/°C for the ordinary and extraordinary refractive indices, respectively. A Sellmeier equation was fit to more extensive room-temperature refractive-index data measured elsewhere.