Patent ID: 11892290
Assignee: NEC CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  A | IPC A  G

Claim 0:
1. An optical coherence tomography apparatus comprising:
a wavelength sweeping laser light source;
a branching and merging device configured to branch a light beam emitted from the wavelength sweeping laser light source into an object light beam and a reference light beam;
an irradiation optical system configured to apply the object light beam to a predetermined scanning range of a measurement object;
a transparent substrate disposed between the measurement object and the irradiation optical system,
wherein the transparent substrate is configured to transmit the object light beam;

a balanced photodetector configured to generate information about a change in an intensity ratio of interference light beams, the interference light beams being generated by the interference between the object light beam and the reference light beam,
wherein the object light beam is scattered from the measurement object after being transmitted through the transparent substrate and then being applied to the measurement object; and

a computer configured to acquire structural data of the measurement object in a depth direction using the information about the change in the intensity ratio of the interference light beams generated by the balanced photodetector,
wherein the transparent substrate comprises a structure configured to change a thickness of the transparent substrate,
wherein the structure is on a surface of the transparent substrate,
wherein the transparent substrate comprises a frame disposed parallel to a direction orthogonal to the depth direction,
wherein the structure comprises a plurality of steps formed in such a way that the thickness of the transparent substrate gradually changes toward a center of the transparent substrate,
wherein the computer is configured to control the irradiation optical system to acquire a plurality of pieces of the structural data in the depth direction while moving an irradiation position of the object light beam along a direction orthogonal to the depth direction of the measurement object, and
wherein the computer is configured to connect the acquired plurality of pieces of the structural data in the depth direction with a position of the structure as a reference.