Photonics Dictionary

Liquid crystals are a state of matter that exhibits properties intermediate between those of conventional liquids and solid crystals. In a liquid crystal, the molecules are ordered like those in a...

An alphanumeric display formed by a layer of liquid crystal material sandwiched between two sheets of glass; a transparent conductive coating on the glass is etched to form the character segments. An...

A liquid crystal light valve (LCLV), also known as a spatial light modulator (SLM), is an optical device that modulates the intensity, phase, or polarization of light passing through it using liquid...

Lithium triborate, commonly abbreviated as LBO, is a nonlinear optical crystal widely used in various applications involving frequency conversion of laser light. It is valued for its excellent...

A lock-in amplifier is a specialized electronic instrument used to extract and measure small signals embedded in noise or interference. It is particularly useful in fields such as spectroscopy,...

A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or attenuating shorter wavelengths. These filters are designed to transmit light with a...

Long-wave infrared (LWIR) refers to a specific range of the infrared spectrum. Infrared radiation is divided into three main categories based on wavelength: near-infrared (NIR), mid-wave infrared...

Low Earth orbit (LEO) refers to a region in space that is relatively close to Earth's surface, typically characterized by altitudes ranging from approximately 180 to 2,000 kilometers (112 to 1,242...

Luminous flux emitted by a source in a given range of directions; the unit of measure is the lumen/steradian, now known as the candela.

A machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated inspection, measurement, and quality control in industrial applications....

Machine vision lighting refers to the use of specific lighting techniques and equipment in the field of machine vision, which is a technology that enables machines to capture and interpret visual...

An arranged series of coils, magnets or electromagnets disposed in such a way that the resulting magnetic fields generate a Lorentz force that is used to then focus or deflect beams of rapidly moving...

A thick meniscus lens arranged concentric with the center of curvature of a spherical mirror to produce an image free of spherical aberration.

A maser (microwave amplification by stimulated emission of radiation) is a device that produces coherent electromagnetic radiation in the microwave frequency range. It is the microwave analog of a...

A device that uses electromagnetic fields to separate electrically charged particles according to their masses. As a beam of charged particles is passed through a mass spectrograph, the result is a...

A wedge in a rangefinder or heightfinder used to displace the image produced by one telescope so that it coincides with that produced by the other telescope, thus affording a measurement of the...

A MEMS fiber optic switch is a microelectromechanical system (MEMS) device designed to selectively route optical signals between multiple fiber optic channels. These switches utilize miniature...

A metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light at a subwavelength scale. Unlike traditional lenses made of glass or other...

In colorimetry, the phenomenon in which spectrally different radiations produce the same color sensation for a given observer. In chemistry, the chemical property of two elements or molecules sharing...

Metaphotonics is an emerging field at the intersection of photonics, metamaterials, and nanotechnology. It involves the design, fabrication, and study of metamaterial-based optical structures and...

Metasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or meta-elements, arranged in a specific pattern to manipulate the propagation of...

Metrology is the science and practice of measurement. It encompasses the theoretical and practical aspects of measurement, including the development of measurement standards, techniques, and...

Micro-optics refers to the design, fabrication, and application of optical components and systems at a microscale level. These components are miniaturized optical elements that manipulate light at a...

Micro-robotics refers to the field of robotics that involves the design, development, and application of miniature robotic systems, often at the microscale. These robots, commonly referred to as...

A microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle detection, imaging, spectroscopy, and night vision technology. It consists of a...

A microdisplay is a miniature electronic display technology that is designed to project visual information onto a small screen. Unlike traditional displays, microdisplays are typically very compact...

Microelectromechanical systems, or MEMS, refer to miniature devices or systems that integrate mechanical and electrical components at a microscale. These systems combine elements such as sensors,...

A camera used to reduce originals onto film for easy storage. There are two basic types: one in which the film is fixed during exposure, and one in which the film is exposed while moving past an...

Microfluidics is a multidisciplinary field that involves the manipulation and control of very small fluid volumes, typically in the microliter (10-6 liters) to picoliter (10-12 liters) range, within...

A microlens array is a grid-like structure composed of numerous small lenses, typically arranged in a regular pattern. Each individual lens in the array is referred to as a microlens. These...

MicroRNAs (miRNAs) are a class of small, single-stranded RNA molecules, typically consisting of about 19 to 24 nucleotides, that play important roles in the regulation of gene expression in cells....

The lens located at the object end of a microscope tube. A wide range of objectives is available, including simple achromats, the color-corrected apochromats and the flat-field objectives. Objectives...

A mid-infrared camera is a type of imaging device designed to capture images in the mid-infrared (mid-IR) spectral range, typically spanning wavelengths from approximately 3 to 12 µm. This...

MWIR stands for mid-wave infrared, referring to a specific range of wavelengths within the infrared spectrum. Infrared radiation is categorized into three main regions based on wavelength:...

Mie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as light) by spherical particles. Unlike Rayleigh scattering, which is...

Modal bandwidth is a crucial parameter in optical fiber communication systems, particularly in multimode fiber (MMF) systems. It quantifies the ability of a fiber optic link to transmit data at high...

A computer-generated, phase-and-amplitude, off-axis hologram made by a multi-exposure technique that uses three computer generated transmission masks. Each mask controls one fixed-phase component of...

A molded lens is an optical lens manufactured using a molding process, typically involving the shaping of a material, such as glass or plastic, into the desired lens shape. This process involves...

A monochromator is an optical instrument used to isolate and select a narrow range of wavelengths from a broader spectrum of light. The term monochromator is derived from "monochromatic," meaning...

A group of photosensors arranged in a grid-like pattern covering the entire field of view, enabling them to record it all at once (as a camera records an image on film) rather than by scanning parts...

A metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor material. Unlike the more common PIN photodiodes, which have a P-type and...

An instrument that contains a spectrograph with a grating in which an array of slits, in place of a photographic plate, is arranged according to the lines of the sample to create an illustration of...

A lens with internally adjustable elements to produce a range of focal lengths. Unlike a true zoom lens, a multifocal lens must be refocused each time the focal length is changed. See variable-focus...

A multihaul transceiver is an optical transceiver module designed to support multiple network architectures or transmission technologies within a single compact device. It offers versatility and...

A coating made up of many layers of material having alternating high and low refractive index. In this way, it is possible to produce coatings with a great variety of properties. These may be...

A multiline laser system refers to a type of laser that is capable of emitting multiple discrete wavelengths or spectral lines simultaneously. Unlike single-line lasers, which produce radiation at a...