A sample observation apparatus includes: an optical element configured to reflect light transmitted through a sample; a moving optical system configured to move in a direction along an optical axis to cause the light from the optical element to be image-formed on an image pickup surface of the image pickup device; and driving unit configured to cause the whole moving optical system to move along the optical axis. The optical element and the moving optical system form a telecentric optical system, and are configured to adjust a focus position by causing the moving optical system to move by the driving unit and configured so that, at the time of causing the moving optical system to move in the direction along the optical axis, an angle of view is constant.

An optical transmitter and a method of producing a low-photon-density modulated optical signal are disclosed. The optical transmitter and method include an optical source configured to emit a continuous optical carrier waveform, a dilation module configured to apply a spreading code to a data payload to spread each of the plurality of symbols in time to expand the symbol duration by a dilation factor and produce a corresponding plurality of time-dilated symbols, the plurality of time-dilated symbols having a lower photon density than the plurality of symbols; a mapping module configured to map the plurality of time-dilated symbols to a modulation scheme; and a modulator configured to modulate the optical carrier waveform with the plurality of time-dilated symbols according to the modulation scheme to produce the low-photon-density modulated optical signal encoded with the plurality of time-dilated symbols corresponding to the data payload.

According to examples, an article may include a base layer that extends along a first dimension and a second dimension, in which the second dimension is orthogonal to the first dimension. The article may also include reflective ribbons provided on an upper surface of the base layer, in which the reflective ribbons positioned along a common plane extending in the second dimension have dihedral angles that change as a function of distance across the common plane.

A laser-based speed gun includes a camera module and a folded optical system including an objective lens and an eyepiece lens. The folded optical system includes first and second image redirecting elements for redirecting an image pathway from the objective lens to the eyepiece lens adjacent the camera module.

An off-axis three-mirror optical system with freeform surfaces comprised an aperture, a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The aperture is located on an incident light path. The primary mirror is located on an aperture side. The secondary mirror is located on a primary mirror reflected light path.

The tertiary mirror is located on a secondary mirror reflected light path. The detector located on a tertiary mirror reflected light path. The primary mirror and the tertiary mirror have a same fifth-order polynomial freeform surface expression. The primary mirror reflected light path, the secondary mirror reflected light path and the tertiary mirror reflected light path overlap with each other.

An example is a lens mirror array in which a plurality of optical elements, which comprises a first lens surface formed at the top of convex portion protruding outwards for converging light, a protrusion which includes a first mirror surface that reflects the light emitted from the first lens surface at the top and a light-shielding surface that has side walls at two sides thereof with respect to a light advancing direction and prevents advance of the light through the side walls, a second mirror surface that reflects the light reflected by the first mirror surface of the protrusion and a second lens surface that images the light emitted from the second mirror surface on an image plane, is arranged in a horizontal scanning direction.

A sunlight redirector has a first mirror array formed of a first plurality of substantially parallel, uniformly spaced, longitudinal outward mirror segments; and a second mirror array formed of a second plurality of substantially parallel, uniformly spaced, longitudinal inward mirror segments. Each mirror segment has a normal vector. The outward mirror segments are adjustably positionable, such that their normal vectors remain parallel. The first mirror array is rotatable about a normal vector of the sunlight redirector. The inward mirror segments may remain fixed in position at all times; or they may be moved, twice per day, between first and second fixed positions.

An optical delay device comprises a multi-pass optical cell including first and second facing curved mirrors defining an optical cavity. One curved mirror includes a spatially extended aperture, such as a wedge-shaped notch aperture formed into the perimeter of the curved mirror. One curved mirror is split into two component mirrors one of which is tilted to define a swirling reflection pattern on the curved mirror that includes the spatially extended aperture. The optical time delay introduced to a light ray by the multi-pass optical cell depends on the input location of the light ray into the spatially extended aperture. The optical delay device may include two such multi-pass optical cells and a mirror that optically couples the two said multi-pass optical cells.

Camera methods and apparatus are described where the camera device includes multiple optical chains. In various embodiments two or more of the optical chains include light redirection devices such as mirrors or prisms. Sensors corresponding to multiple different optical chains, but not necessarily all optical chains, are parallel to each other. In some embodiments sensors corresponding to different optical chains are located in the same plane at the front or rear of the camera. However other sensor mounting positions are also possible.

The present invention relates to an optical element for use in a camera system for the inspection of passageways, a camera system for the inspection of passageways and a method of illuminating a passageway during inspection with a camera. An optical element for use in a camera system for the inspection of passageways comprises a first optical portion arranged to transmit light into a camera, a second optical portion arranged to transmit light emitted from a light source, the second optical portion located adjacent the first optical portion, and barrier means arranged to prevent light being transmitted from the second optical portion into the first optical portion.