YAG
Undoped YAG Crystal is an excellent material for UV-IR optical windows, particularly for high temperature and high energy density application. The mechanical and chemical stability is comparable to sapphire crystal, but YAG is unique with non-birefringence and available with higher optical homogeneity and surface quality. Up to 3'' YAG boule grown by CZ method, as-cut blocks, windows and mirrors are available.
Main Features:
1) Transmission in 0.25-5.0 m m, no absorption in 2-3 m m.
2) Extremely hard and durable.
3) High thermal conductivity.
4) High bulk damage threshold.
5) High index of refraction and Non-birefringence.
Basic Properties:
Crystal structure Cubic
Density 4.5g/cm 3
Transmission Range 250-5000nm
Melting Point 1970°C
Specific Heat 0.59 W.s/g/K
Thermal Conductivity 14 W/m/K
Thermal Shock Resistance 790 W/m
Thermal Expansion 6.9x10 -6 /K
dn/dt, @633nm 7.3x10 -6 /K -1
Mohs Hardness 8.5
Refractive Index 1.8245 @0.8 m m, 1.8197 @1.0 m m, 1.8121 @1.4 m m
Main Specifications of YAG Windows and Mirrors:
Orientation [111] within 5°
Diameter +/-0.1mm
Thickness +/-0.2mm
Flatness better than l /8@633nm
Parallelism better than 30''
Perpendicularity better than 5'
Scratch-Dig 10-5 per MIL-O-1383A
Wavefront Distortion better than λ/2 per inch@1064nm
