Photonics Dictionary: L

The angle between the light input propagation vector and the optical axis of an optical fiber or fiber bundle.

The angle subtended by two points or lines that are just far enough apart to be distinguished as separate. The ability of an optical device to resolve two points or lines is called resolving power...

Flux per unit solid angle leaving a surface in any direction is proportional to the cosine of the angle between that direction and the normal to the surface. A material that obeys Lambert's cosine...

In optics, a plane that emits a flux proportional to the cosine of the angle of the normal; dense opal glass is an example.

A perfectly diffusing surface; the intensity of the light emanating in a given direction from any small surface component is proportional to the cosine of the angle of the normal to the surface. The...

A laser rangefinder is a device that uses laser technology to measure the distance between the device and a target. It operates on the principle of measuring the time it takes for a laser beam to...

A scattering photometer using scattered light in the solid angle 4.51+0 19° with respect to the forward direction, and an impactor with a rectangular jet. Scattered light intensities of entering...

Light generated along the interface when light is incident in the neighborhood of the total internal reflection angle.

A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by optically active substances. Optical rotation, also known as optical activity, is a...

The law stating that when light strikes a surface at such an angle that the reflected and refracted rays are perpendicular to each other, the maximum polarization of the light occurs in both...

The law stating that the angle of reflection is equal to the angle of incidence, the incident ray, reflected ray and normal to the surface, all being located in the same plane.

Lens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance, quality, and characteristics of lenses. These instruments are essential for...

Lensless microscopy, also known as computational or holographic microscopy, is an imaging technique that captures and reconstructs microscopic images without the use of traditional lenses. Instead of...

The apparent visual angle that divides intrabeam viewing from extended-source viewing.

Multimode straight fiber capable of transporting linearly polarized light with any incident polarization angle, and in which no form of internal stress can develop that could lead to birefringence.

Liquid crystal on silicon (LCoS) is a display technology that combines liquid crystal materials with silicon-based semiconductor technology to create high-resolution, high-quality images. LCoS...

A 30-60-90° spectrograph prism that is coated on the surface opposite the 60° angle with a reflecting film.

A mirror employed with a very high incidence angle to form a pair of coherent light sources by reflection, and therefore forming interference bands.

Luminous flux emitted from a surface per unit solid angle per unit of area, projected onto a plane normal to the direction of propagation. Also known as brightness and luminous sterance.

Descriptive of the radiant power of visible light modified by the eye response. It is the measure of the flow of visible light energy past any given point in space in a given time period, and is...

A high-resolution spectroscopic device commonly used in the early 20th century as a component of double-beam interferometers. Light introduced at one end of the plane-parallel glass plate will be...