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Undoped YAG is a substrate and window crystal that can be
used for both UV and IR optic.It is particularly useful for high temperature
and high energy applications.The mechanical stability of YAG is similar to
Sapphire,but YAG is not birefringent and is available with high optical
homogeneity.
Advantages
of Undoped YAG
● Non-birefringent
● High bulk damage threshold
● High index of refraction,facilitating low aberration lens design
● High thermal conductivity
● Stable mechanical and chemical properties
● Low stress and high optical quality
Crystal Symmetry
Hexagonal |
System |
Lattice constant |
a =4.75 ; c =12.97 |
Transparence range |
250-5000nm |
Density |
|
Mohs hardness |
8.5 |
Melting point |
|
Thermal conductivity |
14W/m/K |
Expansion coefficien |
6.9X10 -6/K |
Refractive Index |
1.8197@1064nm |
Typical finished part specifications and tolerances are listed below.
Material............................................... .............................................YAG
Diameter
Tolerance............................................................. ...............+0,
Length
Tolerance.................................................................... ..........
+/
Parallelism........................................................................................
<10 arc seconds
Perpendicularity............................................................................... ..<5 arc minutes
Chamfer............................................................................................
0.13±
Barrel Finish........................................... ...... ........... ......................
50-80 micro-inch(RMS)
Wavefront Distortion Rod.................................... .................... .... .... <λ/8 per inch @632.8nm
Extinction
Ratio..............................................................................
>30dB
Surface
Flatness....................................................... ......................<λ/10
@632.8nm
Surface
Quality.................................................................................
10/5
Clear
Aperture...................................................................................
>95%
Anti-Reflection Coating........................................................................R<0.15%@1064nm per surface
High-Reflection Coating...........................................Standard HR coating with R>99.8%@1064nm and R<5%@808nm