Optical Coherence Tomography (OCT) system and apparatus of this instant application is very useful for diagnosis and management of ophthalmic diseases such as retinal diseases and glaucoma etc. Instant innovative OCT diagnostic system leverages advancements in cross technological platforms. The Michelson interferometric system presented in this application could be used for the OCT imaging, which includes biological OCT imaging, medical OCT imaging, ophthalmic OCT imaging, corneal OCT imaging, retinal OCT imaging, and the like. A tunable filter is placed in front of the detector to make the interferometer more sensitive and accurate for examining various samples for diagnosis.

An optical module 1 includes: a mirror unit 2 including a base 21, a movable mirror 22, and a fixed mirror 16; a beam splitter unit 3 that is disposed on one side of the mirror unit 2 in a Z-axis direction; a light incident unit 4 that causes measurement light L0 to be incident to the beam splitter unit 3; a first light detector 6 that is disposed on the one side of the beam splitter unit 3 in the Z-axis direction, and detects interference light L1 of measurement light which is emitted from the beam splitter unit 3; a support 9 to which the mirror unit 2 is attached; a first support structure 11 that supports the beam splitter unit 3; and a second support structure 12 that is attached to the support 9 and supports the first light detector 6.

In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled to the second coupler via an optical waveguide that induces a delay at least equal to an acquisition time of an image sensor; and an output coupled to the image sensor.

A laser interferometer includes: a laser light source configured to emit first laser light; an optical modulator including a vibration element that generates a vibration component in a direction intersecting an incident surface of the first laser light, and configured to modulate the first laser light by using the vibration element to generate second laser light including a modulation signal; a photodetector configured to receive the second laser light and third laser light that includes a sample signal generated by the first laser light being reflected by an object, and output a light reception signal; a demodulation circuit configured to demodulate the sample signal from the light reception signal based on a reference signal; and an oscillation circuit configured to operate using the vibration element as a signal source and output the reference signal to the demodulation circuit.

In an optical device, an elastic support unit includes a pair of levers which face in a second direction perpendicular to a first direction, a pair of first torsion support portions which are connected between the levers and the base, a pair of second torsion support portions which are connected between the pair of levers and the movable unit, and a first link member that bridges the levers. The levers and the first link member define a light passage opening. Each of connection positions between the levers and the first torsion support portions is located on a side opposite to the movable unit with respect to the center of the light passage opening in a third direction perpendicular to the first direction and the second direction. A maximum width of the light passage opening in the second direction is defined by a gap between the levers in the second direction.

An interferometer system comprises a light redirecting system for splitting an input light beam into two secondary light beams to respectively propagate along a first optical arm and a second optical arm, and for recombining the secondary light beams after exiting the optical arms. The interferometer system also comprises a multipass optical cell positioned at the second optical arm for effecting a predetermined optical path length within the second arm.

A low-coherence interferometer apparatus for determining information on interfaces of an object including: a polychromatic light source; an optical system generating a measurement optical beam and a reference optical beam; a delay line introducing a variable optical delay between the optical beams; detection optics combining the beams, and producing a spectral signal representative of an optical-power spectral density of the resulting interference signal; a control and processing module acquiring a plurality of spectral signals for a plurality of optical delays, determining, for each spectral signal, optical retardation information between interfering beams within a spectral measurement range, analyse the variation in the retardations, and assign the optical retardation determined on the basis of the different spectral signals to interface curves, corresponding to straight lines with positive, negative, zero or almost-zero gradient, depending on the respective optical delay of the acquisition of the spectral signals, and to deduce information of the object.

A broadband interferometry for a measurement range extension beyond a coherence length of a light source includes a wavelength tunable laser as the light source outputting a coherence wavelength beam; and an interferometer disposed between the wavelength tunable laser and a target to be measured and including a reference arm, a measurement arm and a device combining a reference beam and measurement mean to produce a combined interference beam, wherein a local oscillation of the reference beam is replicated by a cavity multiplication or cascading optical delayed lines with a fiber optic cavity, and quantifiable optical properties including a wavelength group delay, a chromatic dispersion, a polarization mode dispersion and a model dispersion are inserted into the local oscillation of the reference beam to incrementally quantify the replicated copies of the local oscillation as the number of the delayed copies of the local oscillation increase for extension of a measurement rage to the target.

In an optical device, a base and a movable unit are constituted by a semiconductor substrate including a first semiconductor layer, an insulating layer, and a second semiconductor layer in this order from one side in a predetermined direction. The base is constituted by the first semiconductor layer, the insulating layer, and the second semiconductor layer. The movable unit includes an arrangement portion that is constituted by the second semiconductor layer. The optical function unit is disposed on a surface of the arrangement portion on the one side. The first semiconductor layer that constitutes the base is thicker than the second semiconductor layer that constitutes the base. A surface of the base on the one side is located more to the one side than the optical function unit.

An optical module includes a mirror unit and a beam splitter unit. The mirror unit includes a base with a main surface, a movable mirror, a first fixed mirror, and a drive unit. The beam splitter unit constitutes a first interference optical system for measurement light along with the movable mirror and the first fixed mirror. A mirror surface of the movable mirror and a mirror surface of the first fixed mirror follow a plane parallel to the main surface and face one side in a first direction perpendicular to the main surface. The movable mirror, the drive unit, and at least a part of an optical path between the beam splitter unit and the first fixed mirror are disposed in an airtight space.