Photonics Dictionary

The transition boundary between P-type and N-type materials in a semiconductor.

In optics, the Pockels effect refers to the phenomenon where the refractive index of a material changes in response to an applied electric field. This effect is utilized in Pockels cells, which are...

A Pockels cell, also known as an electro-optic modulator, is an optical device used to control the polarization of light by applying an electric field. It is named after the physicist Friedrich Carl...

A crystal diode whose rectifying activity is determined by the touching of the crystal to a finely pointed wire surrounded by a material of opposite type.

A device attached to the end of an alignment telescope that detects and calculates a plane mirror's rotation axis that is perpendicular to the line of sight. The device is adaptable for evaluation of...

A polariscope with a half-shade device and an angular scale generally attached to the analyzer. It is used to measure the rotation of the plane of polarization by materials placed within it. A...

A combination of a polarizer and an analyzer that is used to detect birefringence or rotation of the plane of polarization of materials placed between them. Useful for the determination of stress...

A polariton is a quasiparticle resulting from the strong coupling between photons (light particles) and certain types of excitations in a material, such as electronic excitations (electrons and...

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...

A coating made up of particular birefringent materials having polarizing properties. It may be used, in some cases, to replace Polaroid or polarizing prisms.

The process of aligning the crystallites in a piezoelectric material by placing a large DC field across the element at an elevated temperature. The alignment of crystallites results in an increased...

Any of the numerous powders used for grinding and polishing glass, crystal or metal, the chief material being emery and carborundum for grinding, and rouge or the oxides of tin, cerium or other...

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,...

A material used to jacket fiber optic cables. It is chemical- and moisture-resistant, but not fire-resistant.

Polymers are large molecules composed of repeating structural units called monomers. These monomers are chemically bonded together to form long chains or networks, creating a macromolecular...

Process of synthesizing long molecular chain materials (polymers) by reaction of many small molecules (usually thousands) called monomers.

A crystalline material with a high electro-optic coefficient, capable of operating at short wavelengths, with applications in laser, optical disc, printing and microwave systems.

A transition boundary between two regions having different properties in a P-type semiconducting material.

An accurately produced hole of any size and shape that is used as a masking device in an optical system. Pinhole apertures of accurate diameters often are produced by laser beam penetration or by...

In a waveguide, the material in intimate contact with the cladding surface, applied to preserve the integrity of that surface.

Fluorescence produced as a result of the intrinsic property of the material itself or the doping of the material with trace elements.

A prism is a geometric optical element with flat, polished surfaces that refract light. It is typically a solid, transparent object with at least two flat surfaces that are inclined relative to each...

Variations in a signal passing through an optical fiber caused by the effect on the pulse of the fiber's material and mode propagation characteristics.

A noncontact, nondestructive method of measuring defects in thin composite materials, using a xenon flashtube to generate heat in a sample. A thermal imaging system detects differences in the rates...

A technique for depositing a material coating on metal, ceramic, semiconductor or polymer substrates. The interaction of laser energy with the target creates a plume of ablated material that is...

Radiation used to excite an optical or laser material to a higher energy level. See optical pumping.

Q-switched operation, or q-switching, is a technique used in lasers to produce short and intense pulses of light. The term "Q" in q-switching stands for "quality factor," which is a measure of the...

Q-switching, short for "quenching-switching," is a technique used in lasers to generate short, high-energy pulses of light. The term "Q" refers to the quality factor of the laser cavity, which...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics. It is a versatile and powerful device used for emitting coherent light in...

Quantum confinement refers to the phenomenon in quantum mechanics where the motion of charge carriers, such as electrons or holes, is restricted to a region of space that is smaller than their...

A photodetector in which an electrical charge is produced when incident photons change electrons within the detecting material from nonconducting to conducting states. See photoconductive detector;...

Quantum dot light-emitting diode (QLED) is a display technology that utilizes quantum dots, which are semiconductor nanocrystals, to produce vibrant and high-quality images. QLED displays are...

A quantum dot is a nanoscale semiconductor structure, typically composed of materials like cadmium selenide or indium arsenide, that exhibits unique quantum mechanical properties. These properties...

Quantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of photonics or electronics, converts incoming photons (light) into a useful output...

Quantum sensing refers to a class of sensing technologies that leverage principles from quantum mechanics to enhance the precision and sensitivity of measurements. Traditional sensors operate based...

A quantum well is a structure in quantum mechanics that confines particles, such as electrons or holes, in one spatial dimension. This confinement leads to quantized energy levels, creating a...

Quantum-enhanced metrology refers to the use of quantum mechanics principles and techniques to enhance the precision and sensitivity of measurements in metrology—the science of measurement....

A spectrograph used to detect radiation in the range of the ultraviolet in the electromagnetic spectrum. It is made up of quartz because that material, unlike regular glass, is not opaque to the...

A quasiparticle is an emergent phenomenon that occurs in many-body systems, particularly in condensed matter physics, where the collective behavior of a large number of interacting particles can be...

A unit of energy absorbed from ionizing radiation, equal to 100 ergs per gram of irradiated material.

The average length in a specific material in which a relativistic charged particle will lose 67 percent of its energy by bremsstrahlung.

That process by which radiation spontaneously emitted by a volume of optical materials is resonantly reabsorbed within the same volume before it escapes. This effect is manifested in a reduction in...

An instrument used to detect radioactive materials: alpha particles or helium nuclei; beta particles or free electrons; and gamma rays, which are x-rays of very short wavelength. They may be detected...