Optical after-generation manner and its optical delay generator null by the rotary reflector in optical coherence

摘要

PROBLEM TO BE SOLVED: To provide a high speed optical retardation generating method and its high speed optical retardation generator by a rotating reflector in optical coherence tomography capable of providing a tomographic image with a long scanning distance in a depth direction (a Z direction). SOLUTION: The high speed optical retardation generator is provided with a low coherence light source 11, a half mirror 12 bisecting light from the low coherence light source 11 into object light to an object to be inspected and reference light, an optical retardation mechanism 13 with a plurality of prisms arranged radially on a rotor 22 rapidly rotating the reference light so that the light is reflected in a rotor tangent direction, a fixed mirror 14 reflectively returning the reference light from the optical retardation mechanism 13, the half mirror 12 multiplexing the object light returning from the object to be inspected and the reference light returning from the optical retardation mechanism 13, and a photodetector 21 detecting coherent light including a heterodyne coherent beat signal multiplexed by the half mirror 12.