Patent ID: 11947240
Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical apparatus comprising:
at least one light source that emits a light beam containing components of a plurality of wavelengths;
an optical waveguide element that is located on a light path of the light beam;
a light detector; and
an optical system, wherein
the optical waveguide element includes:
a first grating that has a refractive index varying along a moving radius direction of an imaginary circle about a point of incidence of the light beam and that causes part of the light beam to propagate in the optical waveguide element along the moving radius direction as a guided light beam; and
a second grating that is arranged outside the first grating and has a refractive index varying along the moving radius direction and that causes part of the guided light beam to exit from the optical waveguide element as an exiting light beam,

the optical system causes the light beam to enter the first grating and causes a reflected light beam generated by reflection of the exiting light beam on an object to enter the second grating,
part of the reflected light beam entering the second grating propagates in the optical waveguide element and exits from the first grating as an optical feedback beam,
the optical system causes part of the optical feedback beam to enter the light detector as a plurality of separated light beams separated depending on wavelength, and
the light detector detects a light amount of each of the separated light beams.