To provide a reflected light measurement device capable of efficiently performing disconnection inspection on an optical connector, and a plurality of optical fibers. The reflected light measurement device 1 includes a laser light source 2, a beam splitter 3 that branches measurement laser light L into measurement laser light L1 to be transmitted and reference laser light L2 to be reflected, a reference mirror 4 including an optical path length varying mechanism capable of adjusting an optical path length of the reference laser light L2, an optical path length switching unit 5, and switches the optical path length of the reference laser light L2 to a plurality of fixed lengths, and a photometer 6 that receives measurement laser light L1′ reflected at defect sites D1 and D2 such as disconnection inside connectors C1 and C2, and reference laser light L2′ reflected by the reference mirror 4.

A mirror unit 2 includes a mirror device 20 including a base 21 and a movable mirror 22, an optical function member 13, and a fixed mirror 16 that is disposed on a side opposite to the mirror device 20 with respect to the optical function member 13. The mirror device 20 is provided with a light passage portion 24 that constitutes a first portion of an optical path between the beam splitter unit 3 and the fixed mirror 16. The optical function member 13 is provided with a light transmitting portion 14 that constitutes a second portion of the optical path between the beam splitter unit 3 and the fixed mirror 16. A second surface 21b of the base 21 and a third surface 13a of the optical function member 13 are joined to each other.

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.

An optical module 1A includes a mirror unit 2 including a movable mirror 22 and a fixed mirror 16, a beam splitter unit 3, a light incident unit 4, a first light detector 6, a second light source 7, a second light detector 8, a holding unit 130, a first mirror 51, a second mirror 52, and a third mirror 53. The holding unit 130 holds the first light detector 6, the second light detector 8, and the second light source 7 so as to face that same side, and to be aligned in this order. A length of an optical path between the unit 3 and the detector 6 is shorter than a length of an optical path between the unit 3 and the detector 8, and a length of an optical path between the unit 3 and the source 7.

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.

Inspecting a multilayer sample may include receiving, at a beam splitter, light and splitting the light into first and second portions; combining, at the beam splitter, the first portion of the light after being reflected from a multilayer sample and the second portion of the light after being reflected from a reflector; receiving, at a computer-controlled system for analyzing Fabry-Perot fringes, the combined light and spectrally analyzing the combined light to determine a value of a total power impinging a slit of the system for analyzing Fabry-Perot fringes; determining an optical path difference (OPD); recording an interferogram that plots the value versus the OPD for the OPD; performing the previous acts of the method one or more additional times with a different OPD; and using the interferogram for each of the different OPDs to determine the thicknesses and order of the layers of the multilayer sample.

Provided is an observation target cover for interference observation using first light and second light having a coherent length longer than that of the first light so as to acquire an interference light image of an observation target by the first light while adjusting an optical path length difference based on an interference result of the second light, the observation target cover including: a transmission reflection portion that transmits the first light and reflects the second light; and a support portion for supporting the transmission reflection portion so that a placement surface on which the observation target is placed and the transmission reflection portion face each other with a predetermined gap therebetween.

An optical coherence tomography (OCT) system comprises an interferometer configured to generate interference light based on interference between a reference beam and a sample beam with which a sample has been irradiated. A detector operates to detect intensities of the interference light and/or one or more interference patterns; a processor is configured measure a signal falloff of the intensity of the interference light and/or the one or more interference patterns; and an optical delay line configured to adjust an optical path difference according to the signal falloff so as not substantially introduce artifacts to an image of the sample. In one embodiment, the optical delay line includes a main reflector consisting of a mirror and a Faraday rotator; the Faraday rotator is placed between the n and n+1 coherence revival modes of the interferometer, where n is greater than or equal to 1.

Retinal imaging systems and related methods employ a user specific approach for controlling the reference arm length in an optical coherence tomography (OCT) imaging device. A method includes restraining a user's head relative to an OCT imaging device. A reference arm length adjustment module is controlled to vary a reference arm length to search a user specific range of reference arm lengths to identify a reference arm length for which the OCT image detector produces an OCT signal corresponding to the retina of the user. The user specific range of reference arm lengths covers a smaller range of reference arm lengths than a reference arm length adjustment range of the reference arm length adjustment module.

To provide a reflected light measurement device capable of efficiently performing disconnection inspection on an optical connector, and a plurality of optical fibers. The reflected light measurement device 1 includes a laser light source 2, a beam splitter 3 that branches measurement laser light L into measurement laser light L1 to be transmitted and reference laser light L2 to be reflected, a reference mirror 4 including an optical path length varying mechanism capable of adjusting an optical path length of the reference laser light L2, an optical path length switching unit 5, and switches the optical path length of the reference laser light L2 to a plurality of fixed lengths, and a photometer 6 that receives measurement laser light L1 reflected at defect sites D1 and D2 such as disconnection inside connectors C1 and C2, and reference laser light L2 reflected by the reference mirror 4.