Photonics Dictionary

Microscopy technique to convert the phase structure of the wave transmitted or reflected by the specimen into a corresponding intensity structure in the image plane.

A phase-modulated sensor is a type of sensor that uses modulation of the phase of a signal to measure changes in a physical quantity. In such sensors, variations in the phase of the signal are...

Photoconductive antenna (PCA) is a semiconductor element that generates or detects high-frequency electromagnetic signals. Compact PCAs based on gallium arsenide (GaAs) or indium gallium arsenide...

An input device for a computer that detects and reads the data, in the form of punched holes in cards, by light that is transmitted through the holes.

Photocells of various kinds used to measure photometric quantities; i.e., intensity, luminance and illuminance. Meter readings are used to express illuminance and, by calibration, to measure...

The coupling of two circuits by the use of a light pipe through which photons are transmitted.

A photonic integrated circuit (PIC) is a compact and integrated device that incorporates multiple photonic components and functions on a single chip, similar to the way electronic integrated circuits...

Photoplethysmography (PPG) is a non-invasive optical technique used to detect changes in blood volume in tissues. It measures variations in light absorption caused by the pulsatile nature of blood...

A document-transmitting process that uses a cylinder that rotates the document to be scanned and detected by a photoelectric cell. The cell transforms the light into electrical energy that may be...

Plastic optical fiber (POF) is a type of optical fiber made from transparent plastic, typically polymethylmethacrylate (PMMA) or polycarbonate. Unlike traditional glass optical fibers, which are made...

The property exhibited by certain birefringent crystals in which the degree with which they transmit polarized light is different, depending on whether the ray is ordinary or extraordinary. An...

Polarization refers to the orientation of oscillations in a transverse wave, such as light waves, radio waves, or other electromagnetic waves. In simpler terms, it describes the direction in which...

Single-mode fiber that preserves the plane of polarization of the light launched into it as the beam propagates through its length. Also called polarization-maintaining fiber. The polarization is...

A substance that transmits the infrared, but which is too delicate or fragile to be used in the form of a single crystal. Instead, the pure material is finely ground, pressed to the required shape,...

Power modulation refers to the intentional variation of power levels in a signal, often in the context of electronic communication systems. This modulation technique is used to encode information...

Technique using a fiber optic assembly to illuminate an opaque object and transmit an image back from it without a lens system on the distal end.

A method of sensing by transmitting energy from the sensor and detecting the energy after it has been reflected by the object in its path.

An instrument designed for laser technology that is used to extract single pulses from the laser and transmit a portion of the pulses, thereby reducing the pulse rate to a desirable frequency.

Conceptual formulas that characterize both the transmittance functions of lenses and propagation in the Fresnel zone.

Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical phase information of transparent specimens. Unlike traditional brightfield...

Quantum key distribution (QKD) is a method of secure communication that utilizes principles from quantum mechanics to establish a shared secret key between two parties, typically referred to as Alice...

A lamp with a quartz envelope that transmits radiation generally rich in the ultraviolet.

Ratio of the radiance of the specimen to that of a perfect reflecting or transmitting diffuser identically irradiated.

A photograph transmitted by radio waves.

When light is transmitted through matter, part of the light is scattered in random directions. A small part of the scattered light has frequencies removed from the frequency of the incident beam by...

A device that is used to determine the index of refraction of a gas or liquid through the interference patterns formed by two beams of light, one of which has been transmitted by the sample. A single...

The transparent component of an optical reader that transmits the image rays of the characters to be read.

The output of spectral channels written as an integral function of known solar irradiance, atmospheric transmittance and camera spectral responsivity, and the unknown spectral reflectance.

A photographic method used to obtain an image of a subject by means of its reflectance of incident ultraviolet radiation. An ultraviolet source is used to irradiate the subject, while the reflected...

A prism having several plane polished surfaces, some to transmit light, some to reflect light, and some to serve both functions in succession. It acts generally as a group of plane mirrors held in a...

Remote inspection refers to the process of inspecting, evaluating, or monitoring assets, equipment, infrastructure, or systems from a distance, typically using remote sensing technologies and...

A reflecting prism that is rhomboidal in shape. It has two parallel transmitting faces, and two parallel reflecting faces; the latter are oblique to the former (usually but not necessarily at...

A type of 45-90-45° prism used to bend a beam of light through a right angle with the surfaces forming the 90° angle acting as transmitting faces.

A Risley prism, also known as a Risley prism pair or Risley rotating prism, is an optical device used for controlling the direction of a laser beam or other optical beam by independently rotating two...

A polarizing prism assembly made up of two cemented calcite halves. The prism transmits the ordinary ray without deviation, while the extraordinary ray is deviated to accomplish the polarization.

Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide (Al2O3) that is highly transparent in the infrared region of the electromagnetic...

Sapphire refers to a crystalline form of aluminum oxide (Al2O3) that is used in various optical and photonic applications due to its exceptional optical, mechanical, and thermal properties. Sapphire...

A double-plate device used to transmit polarized light and form interference fringes of the light, thus indicating its presence. It consists of two calcite plates of equal thickness, cut parallel to...

1. A polariscope consisting of a Savart plate and a tourmaline plate analyzer, and used to produce parallel color fringes by transmitting polarized light. 2. A polariscope composed of an analyzing...

Also called scanning laser acoustic microscope. A device that uses high-frequency ultrasound waves to penetrate surfaces. A scanning laser beam is used as a detector, which transmits information...

The large, usually flat surface onto which an image is projected for viewing. May be reflecting or transmitting (rear projection).