Patent ID: 11892438
Assignee: ASAHI KASEI MICRODEVICES CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. The optical densitometer according to claim 1, wherein
at least one of the light propagation portion and the extension region comprises an end portion,
the end portion of the light propagation portion and the diffraction grating portion are separated from each other, and/or the end portion of the extension region and the light propagation portion are separated from each other, at a distance greater than a distance given by the following Expression (2):, 3
          ⁢
          
            λ
            0
          
        
        
          2
          ⁢
          π
          ⁢
          
            
              
                n
                pro
                2
              
              -
              
                n
                gap
                2
              
            
          
        
      
    
    
      
        Expression
        ⁢
        
          
        
        ⁢
        
          (
          2
          )
        
      
    
  

where λ0 represents the average wavelength, in vacuum, of the light propagating through the core layer, npro represents a refractive index of a material forming the light propagation portion or the extension region, and ngap represents a refractive index of a material present in a portion sandwiched between the end portion of the light propagation portion and the diffraction grating portion, or a refractive index of a material present in a portion sandwiched between the end portion of the extension region and the light propagation portion.