Photonics Dictionary: P

A camera designed to form a continuous record of an expansive section of the horizon. The typical panoramic camera is mounted to rotate about a vertical axis. A slit opening in the film plane and the...

A concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a paraboloidal surface through which the axis does not pass, and is known as an...

An array of lines in the infrared region of the emission spectrum of atomic hydrogen. Their wave numbers are expressed by the equation: where represents the wave number in the reciprocal centimeters,...

A prism made up of two air-spaced components. It has the ability to revert, and not invert, an image, and can be used in convergent, divergent and parallel light. May be rotated to compensate for...

A five-sided prism containing two reflecting surfaces at 45° to each other, and two refracting faces perpendicular to the entering and emerging beams. The deviation angle of 90° is...

A source of light will not cast a distinct shadow of an interfering, opaque object, but will cast a shadow having two parts: 1. the umbra, or the central, totally dark part of the shadow; and 2. the...

An optical instrument designed to displace the line of sight in a vertical direction. For submarines and other military uses the periscope is a long tube containing prisms at both ends and...

A high-speed, narrow-field lens consisting of two achromats spaced about the aperture stop. Its uses include portrait photography and motion picture projection.

A paraboloidal surface on which the image is located when there is no astigmatism.

Phase contrast microscopy is an optical microscopy technique that enhances the contrast of transparent and colorless specimens, making it possible to visualize fine details and internal structures...

Phase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent light. It refers to the condition where the phases of two or more waves,...

A microscope that has an annular stop in the lower focal plane of the condenser, and a quarter-wave retarding and absorbing ring in the upper focal plane of the objective that just fills the image of...

A photodiode detector is a semiconductor device that converts light into an electrical current. It operates based on the principle of the photoelectric effect, where photons of light incident on the...

A two-electrode, radiation-sensitive junction formed in a semiconductor material in which the reverse current varies with illumination. Photodiodes are used for the detection of optical power and for...

Photoelastic equipment and supplies refer to instruments and materials used in photoelasticity, a technique used to analyze stress distribution and behavior in materials. photoelastic equipment...

A device consisting of a microammeter, a photovoltaic cell and a battery. It is used for the measurement of scene brightness and the determination of correct exposure for photographic processes.

A quantum of electromagnetic energy of a single mode; i.e., a single wavelength, direction and polarization. As a unit of energy, each photon equals hn, h being Planck's constant and n, the frequency...

The technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. The science includes light emission, transmission, deflection, amplification and...

Photonics contract manufacturing refers to the outsourcing of the production of photonics-related components, devices, or systems to specialized manufacturing firms. Photonics involves the...

A photovoltaic cell, commonly known as a solar cell, is a semiconductor device that directly converts light energy into electrical energy through the photovoltaic effect. The photovoltaic effect is...

Piezoelectric transducers are devices that utilize the piezoelectric effect to convert electrical energy into mechanical vibrations or vice versa. The piezoelectric effect is a property exhibited by...

The formula describing the spectral radiant emittance of a perfect blackbody as a function of its temperature and the wavelength of the emitted radiation. where Wλ equals radiation...

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...

Plastic optics refers to optical components or systems that are made from transparent plastic materials, as opposed to traditional optical components made from glass or other materials. Plastic...

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...

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 polygonal mirror, also known as a multifaceted mirror or facet mirror, is a type of optical component used in various laser systems, optical scanners, and imaging devices. It consists of a flat or...

The condition in which there are more atomic systems in the upper of two energy levels than in the lower, so stimulated emission will predominate over stimulated absorption. This condition may be...

A camera system that uses a fine powder to diffract x-rays from the specimen. A beam of monochromatic x-rays passes through a collimator onto the specimen. Diffracted x-rays are recorded on the film...

In a lens or lens system, that surface at which the projections of an entering and exiting ray intersect. Also known as the equivalent refracting surface, the principal plane is most often not...

A pair of telescopes with prismatically erected images, mounted side by side with the eyepieces at the interocular distance of the observer. This separation is adjustable with a convenient millimeter...

The power, expressed in prism diopters, that is the linear displacement, in centimeters, produced by the prism one meter away.

Unlike the thermocouple or bolometer, the pyroelectric infrared detector is a current source with an output proportional to the rate of change of its temperature. Capable of extremely rapid response...