Undoped YAG Crystal is an excellent material for UV-IR optical windows, particularly for high temperature and high energy density applications. 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 from Dream Lasers.


Main Features:

l Transmission in 0. 25 - 5.0mm, no absorption in 2 - 3mm.
l Extremely hard and durable
l High thermal conductivity
l High bulk damage threshold
l High index of refraction and Non-birefringence

Basic Properties:
Crystal Structure Cubic
Density 4.5 g/cm3
Transmission Range 250 - 5000 nm
Melting Point 1970 oC
Specific Heat 0.59 W · s · g-1 · K-1
Thermal Conductivity 14 W·m-1·K-1
Thermal Shock Resistance 790 W /m
Thermal Expansion 6.9x10-6 /K
dn/dT, @ 633nm 7.4x10-6 /K-1
Mohs Hardness 8 ~ 8.5
Refractive Index 1.8245 @ 0.8mm, 1.8197 @ 1.0mm, 1.8121 @ 1.4mm
Main Specifications of YAG Windows and Mirrors:
Orientation [111] within 5o
Diameter +/-0.1 mm
Thickness +/-0.2 mm
Flatness better than λ/8 @ 633 nm
Parallelism better than 30"
Perpendicularity better than 5'
Scratch-Dig 10-5 per MIL-O-13830A
Wavefront Distortion better than λ/2 per inch @ 1064 nm
Other high-precision windows, AR- and HR-coatings are available upon request.