A fiber module (1B) according to the present disclosure includes an input-side optical fiber (11), an output-side optical fiber (12), a ferrule (20) in which the input-side optical fiber and the output-side optical fiber are insertable in both ends and a groove (32) is formed in a direction orthogonal to a longitudinal direction (D1) in the middle of the longitudinal direction, a dielectric multilayer film filter (30) inserted in the groove, and an input-side GI fiber (15) and an output-side GI fiber (16) joined by fusion to respective terminal portions of the input-side optical fiber and the output-side optical fiber. The dielectric multilayer film filter is interposed between an end surface (15f) of the input-side GI fiber and an end surface (16f) of the output-side GI fiber in the longitudinal direction.

A submersible optical module and system to contain and protect fiber optic cables within a splice tray. Access holes on the module allow for an entry point and exit point of the optical fibers. Once set up with the module cavity containing the desired fiber optic cables, the remaining void space of the module cavity is filled with an epoxy creating a protective seal and barrier to provide superior protection to fiber optic cables from moisture.

A three in one combination imaging module comprising a light guide positioned in a light guide holder, a light emitting diode module, and a doublet or GRIN lens array held in a housing. The light guide holder and the housing comprise mating connecting elements. The connecting elements comprise locking elements, tabs, notches, slots, and clips that cooperate and interact in order to securely hold and accurately position each of the components in the housing without the use of adhesive. Light emitted by the light emitting diode module enters, travels through, and then exits the light guide and is received by the doublet or GRIN lens array and then focused on a sensor array and captured.

A three in one combination imaging module comprising a light guide positioned in a light guide holder, a light emitting diode module, and a doublet or GRIN lens array held in a housing. The light guide holder and the housing comprise mating connecting elements. The connecting elements comprise locking elements, tabs, notches, slots, and clips that cooperate and interact in order to securely hold and accurately position each of the components in the housing without the use of adhesive. Light emitted by the light emitting diode module enters, travels through, and then exits the light guide and is received by the doublet or GRIN lens array and then focused on a sensor array and captured.

An optical filter device includes: a first multi-core optical fiber including a plurality of first cores; a first lens; an optical filter which is rotated by a rotation angle about a rotation axis; a second lens; and an optical fiber including cores which the emission light beams from the second lens enter. When directions directed from a reference axis toward one side and another side with respect to the reference axis along an orthogonal axis orthogonal to an optical axis and the reference axis are defined as first and second orthogonal directions, respectively, a circumferential orientation of the first multi-core optical fiber is set so that a separation distance is minimized. The separation distance is a sum of distances from the reference axis to first cores that are most separated away from the reference axis in the first and second orthogonal directions, respectively.

An interference filter module comprises two optical fiber collimators arranged on an optical axis so as to be opposed to each other, interference filters, and a casing including a main body portion and filter holding portions to be mounted into the main body portion, which are configured to hold the interference filters. Two interference filters including a kth filter when counted from a front end and a k-th filter when counted from a rear end are determined as a k-th set. The two interference filters of the k-th set are accommodated in two filter holding portions, each of which is a k-th holding portion when counted from the front end and the rear end, respectively. The two filter holding portions have rotation axes in directions orthogonal to a fore-and-aft direction and are rotatably held by the casing. The rotation axes of the filter holding portions are orthogonal to each other.

In a wavelength selective filter, an optical fiber collimator, an interference filter, and a reflective plate are arranged in this order from front to rear along a z-axis. The collimator has a collimator lens disposed on the rear side of an optical fiber that is opened. The interference filter includes light incident and emitting surfaces, opposed with their xy-planes rotated about a y-axis at a predetermined rotation angle. The reflective plate has a front reflective surface having a normal direction along a z-axis direction, and reflects, toward the front, light incident from the front through the interference filter, to be incident onto the interference filter. The optical fiber collimator causes the input light propagating through the optical fiber from the front to be incident onto the interference filter, and converges the reflected light transmitted through the interference filter to the optical fiber and outputs the light.

The optical receiver portion of an optical sensing system (such as, for example, a LIDAR system) includes a tunable narrowband optical filter that is used in combination with a feedback element to continuously monitor the received (reflected) optical signal and adjust the center wavelength of the narrowband optical filter to follow recognized shifts in the source wavelength. These slight adjustments to the center wavelength of the optical filter (as controlled by the feedback element) ensure that the passband of the optical filter tracks any shift/drift in the source wavelength, without requiring any direct connection/wavelength monitoring between the source and the receiver, and also without the need to utilize complex wavelength stability configurations at the source.

An optical test apparatus includes a collimator comprising a dual-fiber ferrule and a collimating lens. The optical test apparatus also includes an optical filter optically aligned with the collimator, a first optical fiber pigtail connected to the collimator at a first bore of the dual-fiber ferrule, a second optical fiber pigtail connected to the collimator at a second bore of the dual-fiber ferrule, and a photodetector in optical communication with the collimator. The optical test apparatus defines a reflection path from the first optical fiber pigtail to the optical filter and from the optical filter to the second optical fiber pigtail and a transmission path from the first optical fiber pigtail through the optical filter to the photodetector.

A device. At least some example embodiments are a device including a filter element configured to receive optical energy from a first optical fiber. The filter element is reflective in a preselected band of optical wavelengths. A first lens is configured to receive optical energy transmitted through the filter element. A shell is disposed about the optical filter and the first lens; surfaces of the first lens, the filter element and the shell form a first boundary portion of an internal volume of an interior of the shell. A fluid is sealably disposed within the internal volume.