Patent ID: 11888438
Assignee: KABUSHIKI KAISHA TOSHIBA
Field: Optics (Instruments)
Classification: CPC H  F  G  Y | IPC F  G  H

Claim 0:
1. An optical element comprising:
a continuous gradient index distribution area which is configured to continuously attenuate gradient index from a center of the optical element in a radial direction; and
a first medium at the center, the first medium including an area where absolute value of an imaginary part of a complex refractive index of the area is greater than the continuous gradient index distribution area outside the first medium, and the area absorbing light,
when a refractive index of the continuous gradient index distribution area is N, a radius from the center is r>0, a maximum value of the radius r is r0, a refractive index of an environment outside an outer peripheral surface of the optical element is NO which is a constant, and m is a constant of 1 or more,, N
  =
  
   
    
     N
     0
    
    (
    
     
      r
      0
     
     r
    
    )
   
   m, is fulfilled.