Patent ID: 8755050

Claim:
An optical coherence tomography (OCT) apparatus, comprising: a light source, for emitting a coherent light; a light coupling module, for dividing the coherent light into a first incident light and a second incident light, wherein the first incident light is emitted to an item to be inspected and a first reflected light is generated; and an optical path difference generating module comprising at least one optical device, when the second incident light is emitted to the optical path difference generating module, the optical, path difference generating module changing the transparent/reflection properties of the at least one optical device to generate a second reflected light according to the second incident light to generate an optical path difference between the first reflected light and the second reflected light; wherein the at least one optical device is a plurality of light switch units including a first electro-chromic switch and a second electro-chromic switch, and the first electro-chromic switch and the second electro-chromic switch are formed by electro-chromic material; when the optical path difference generating module is operated in a first mode, the second incident light emitted to the optical path difference generating module will firstly meet the first electro-chromic switch in the off-state, the first electro-chromic switch in the off-state will reflect the second incident light out of the optical path difference generating module to form a first mode second reflected light; when the optical path difference generating module is operated in a second mode, the second incident light emitted to the optical path difference generating module will firstly meet the first electro-chromic switch in the on-state, the second incident light will pass through the first electro-chromic switch in the on-state and then meet the second electro-chromic switch in the off-state, the second electro-chromic switch in the off-state will reflect the second incident light out of the optical path difference generating module to form a second mode second reflected light; a first optical path difference between the first reflected light and the first mode second reflected light when the optical path difference generating module is operated in the first mode is different from a second optical path difference between the first reflected light and the second mode second reflected light when the optical path difference generating module is operated in the second mode.