The Transmission Curves and Refractive Index Data represent typical optical material properties of eSource Optics standard Windows, Lenses and VUV-UV Filter & Mirror Substrate materials (based on ~2-3mm Thickness).  Materials transmittance can vary slightly and this data should be used as a reference only.
                      
eSource Optics Window, Lens & Substrate VUV-UV % Transmission & Optical Material Properties:
 
VUV Grade Magnesium Fluoride:  VUV Grade Magnesium Fluoride (MgF2) exhibits high transmission properties from ~ 110nm Vacuum UV (VUV) to ~ 6.0um in the Infrared.  VUV Grade MgF2 is a relatively hard crystalline material resistant to mechanical and thermal shock.  VUV Grade MgF2 is a birefringent crystal that typically can be oriented along the optical axis to avoid birefringent effects in windows & lenses.  The Refractive Index data listed below is the nominal average 'N' data for both the Ordinary (o) & Extraordinary (e) Rays.  VUV Grade Magnesium Fluoride (MgF2) is used as the substrate material for all eSource Optics VUV Narrowband Optical Filters from 120-130nm. 

                                                                   (Typical VUV MgF2 % Transmission based on 3.0mm Thickness*)                                                
 
                                                          MgF2 Refractive Index (Avg.)
	
		
			| Wavelength, nm | 157 | 193 | 248 | 308 | 350 | 
		
			| Refractive Index (n) | 1.464 | 1.428 | 1.4097 | 1.398 | 1.393 | 
	
   
  
 
  
UV Grade Calcium Fluoride: UV Grade Calcium Fluoride (CaF2) exhibits good transmission properties from ~ 140nm Vacuum UV (VUV) to ~ 8.0um in the Infrared.  UV Grade CaF2 is a relatively soft crystalline material and care should be taken as CaF2 is sensitive to mechanical and thermal shock.  UV Grade CaF2 is a cubic single crystal optical material.  UV Grade Calcium Fluoride (CaF2) is used as the substrate material for all eSource Optics VUV Optical Filters from ~130-150nm depending on FWHM.

                                                      (Typical VUV CaF2 % Transmission based on 3.0mm Thickness*)
                                                               
                                                  CaF2 Refractive Index 
	
		
			
				| Wavelength, nm | 157 | 193 | 248 | 308 | 350 | 
			
				| Refractive Index (n) | 1.559 | 1.501 | 1.468 | 1.453 | 1.445 | 
		
	
 
 
 
Sapphire:  Sapphire (Al2O3) exhibits good transmission over the range extending from ~ 150nm in the Vacuum UV (VUV) to ~ 5.0um in the Mid-Infrared.  Sapphire is an exceptional hard material; is chemically inert and insoluble to water, common acids, or alkalis at temperatures up to ~1,000 °C. Sapphire is typically oriented so that the c-axis of the crystal is parallel with the optical axis.

 
                          Sapphire (Al2O3) Refractive Index ( (0) & (e) avg.)
	
		
			
				
					| Wavelength, nm | 200 | 248 | 280 | 313 | 365 | 
				
					| Refractive Index (n) | 1.907 | 1.842 | 1.820 | 1.805 | 1.789 | 
			
		
	
 
 
 
 
 
 
 Cultured Quartz Crystal: Quartz Crystal exhibits good transmission properties from ~ 147nm Vacuum UV (VUV) to ~ 2.5um in the Infrared.  Quartz Crystal is a very hard crystalline material with low thermal expansion coefficient.  Quartz Crystal is a grown crystalline form of Silicon Dioxide (SiO2) optical material.  Quartz Crystal is used as the substrate material for all eSource Optics VUV Optical Filters from ~150-170nm depending on FWHM.
 

  
                                           Cultured Quartz Crystal Refractive Index
	
		
			
				
					| Wavelength, nm | 157 | 193 | 248 | 308 | 350 | 
				
					| Refractive Index (n) | 1.660 | 1.562 | 1.508 | 1.486 | 1.476 | 
			
		
	
 
 
 
 
UV Grade Fused Silica:  Synthetic form of silicon dioxide made from SiCl4, which transmits light over a very broad range of wavelengths from ~ 170 nm to 2.5 µm.  UV Grade Fused Silica is a high-purity material which has excellent thermal stability, high transmittance and is used as a UV to NIR material for many optical components.  UV Grade Fused Silica is used as the substrate material for all eSource Optics VUV-UV Optical Filters from 180-320nm.
 

  
               
                                                              UV Grade Fused Silica Refractive Index   
	
		
			
				| Wavelength, nm | 193 | 248 | 308 | 355 | 405 | 
			
				| Refractive Index (n) | 1.561 | 1.508 | 1.485 | 1.476 | 1.469 | 
		
	
 
 
 
                             
 
                      
                     BK7 Glass: Borosilicate crown optical glass with low bubble content and high homogeneity (same optical properties throughout
                     the material).  BK7 is an excellent visible to NIR material for many optical components.
 
                        
 
                              
                                        N-BK7 Glass Refractive Index   
	
		
			
				| Wavelength, nm | 365 | 405 | 546 | 706 | 850 | 
			
				| Refractive Index (n) | 1.536 | 1.530 | 1.519 | 1.513 | 1.509 | 
		
	
                                                                            
                      
 
                                   
 
                                   VUV-UV Optical Materials % Transmission Overview:           
                    
    
 
                      (*Materials transmittance can vary slightly and this data should be used as a reference only.)                                                     
 
 
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