Ellipitical Window / Brewster Window

The window cutted as brewster angle, It's used as polarizer in laser cavity.    
 
Brewster Windows are uncoated substrates which are used as polorizers, typically within a laser cavity. Positioned at Brewster's Angle the P-Polarization portion of the light will pass through the window with no losses while the S Polarization portion will be reflected off the brewster window. Used in a laser cavity the brewster window is essentially a polorizer.     
  
Brewster's Angle is calculated from:    
 θ= tan-1(n)    
 where θ is Brewster's Angle and n is the refraction index of the material.     
 
Material: BK7 or Fused silica     
Specifications:    
Diameter Tolerance: +0.0, -0.1mm     
Thickness Tolerance: ± 0.2mm    
Clear Aperture: >85%   
Surface Quality: 10-5 scratch and dig      
Wavefront transmission: λ/10 @632.8nm    
Parallelism: <5 arc seconds   
Protective Bevel