A focusing device comprises a base unit and a mirror unit which is translatable relative to the base unit parallel to an optical axis of the focusing device. The mirror unit is configured to receive incident light along the optical axis in a first direction and to reflect the incident light parallel with the optical axis in said first direction. The mirror unit comprises at least four mirrors, at least one of the mirrors being curved.

An optical device for a head-mounted display device includes a first partial reflector and a second partial reflector positioned relative to the first partial reflector so that the second partial reflector receives first light transmitted through the first partial reflector and reflects at least a portion of the first light toward the first partial reflector as second light. At least a portion of the second light is reflected by the first partial reflector as third light, and at least a portion of the third light is transmitted through the second partial reflector. At least one of the first partial reflector or the second partial reflector includes a reflective holographic element.

An omnidirectional image and video capturing system including a tube, a plurality of reflectors, openings for rays of light to the enter tube, and a stitching, display or decoding non-transitory storage media. The reflectors may include a first mirror, a second mirror, a third mirror, and a fourth mirror and may be angled at an approximate 45-degree angle and a fifth mirror that may capture reflected images from the first (4) four mirrors.

An omnidirectional image and video capturing system including a tube, a plurality of reflectors, openings for rays of light to the enter tube, and a stitching, display or decoding non-transitory storage media. The reflectors may include a first mirror, a second mirror, a third mirror, and a fourth mirror and may be angled at an approximate 45-degree angle and a fifth mirror that may capture reflected images from the first (4) four mirrors.

Methods and apparatus for measuring the melt depth of a substrate during pulsed laser melting are provided. The apparatus can include a heat source, a substrate support with an opening formed therein, and an interferometer positioned to direct coherent radiation toward the toward the substrate support. The method can include positioning the substrate with a first surface in a thermal processing chamber, heating a portion of the first surface with a heat source, directing infrared spectrum radiation at a partially reflective mirror creating control radiation and interference radiation, directing the interference radiation to a melted surface and directing the control radiation to a control surface, and measuring the interference between the reflected radiation. The interference fringe pattern can be used to determine the precise melt depth during the melt process.

An optical redirection adapter for an electronic device having a camera includes a housing. An optical element is attached to the housing and positioned such that, when the adapter is attached the electronic device, the optical element is positioned in the camera's field of view. The optical element reflects light in the camera's field of view from a redirection angle that is offset from the camera's field of view. The optical redirection adapter facilitates ergonomically sound use of the camera.

A view redirecting system for use on a mobility device to redirect a user's view to a more favorable orientation is disclosed. One embodiment includes a first structure having a convex first reflective surface, a second structure having a flat second reflective surface and a third structure. The third structure being an adjustable structure and configured for connecting said first and second structures together. The first structure and the second structure are configured to be positioned such that the first reflective surface and the second reflective surface are facing each other at angle up to and including ninety degrees. The third structure configured to maintain the angle. The system is arranged to redirect a user's view from a first line-of-sight to a second line-of-sight by light interacting with the reflective surfaces The system being configured for attachment to a structural member of the mobility device.

A recycling optical cavity is defined at least by first and second optical films and is configured to receive a test material therein. The test material is configured to emit at least a second light having a second wavelength when irradiated with a first light having a first wavelength. For at least one of s- and p-polarized incident lights incident in an incident plane, and at the first and second wavelengths: at a first incident angle, the first optical film has respective optical transmittances T11(θ1) and T12(θ1), and the second optical film has respective optical transmittances T21(θ1) and T22(θ1), wherein T11(θ1)>T12(θ1), T21(θ1), T22(θ1); and at a second incident angle, the first optical film has respective optical transmittances T11(θ2) and T12(θ2), and the second optical film has respective optical transmittances T21(θ2) and T22(θ2), wherein T21(θ2)>T11(θ2), T12(θ2), T22(θ2).

Provided is an ATR prism, including a material having an internal transmittance of 90% or higher at a wavelength falling within a wavelength range of from 8 μm to 10 μm, when the material has a thickness of 2 mm. The ATR prism includes: a first surface including a first totally reflecting surface; a second surface including a second totally reflecting surface; and a recessed portion formed in one of the first surface or the second surface.

Provided are transaction cards including an infinity mirror. In some approaches, a transaction card may include a body comprising a first reflective layer and a second reflective layer, and a light source between the first reflective layer and the second reflective layer.