Photonics Dictionary: P

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.

The product of exposure time and irradiance or illuminance.

A hologram that is formed on a recording medium by changing the phase of the illuminating wave in correspondence with the recording exposure. It may be formed by contact printing onto a resist...

In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it. The phase mask is used to control the spatial distribution of the light's...

A process used in pyrometry and photothermometry to create a photographic record of a surface's temperature gradients. Essentially, it involves the exposure of a glowing phosphorescent surface to the...

Photobleaching is a phenomenon in which the fluorescence of a fluorophore (a fluorescent molecule or dye) is permanently reduced or eliminated upon prolonged exposure to light. This process occurs...

Photochromic refers to a property exhibited by certain materials, typically organic compounds or dyes, which undergo reversible changes in color when exposed to light. Specifically, photochromic...

The current that flows through a photosensitive device, such as a photodiode, as the result of exposure to radiant power.

The measurement of the responsivity of photographic media and of the relations between exposure and density of developed images.

A measure of the total light passed by a shutter during an exposure, compared with the light that could be passed by an idealized, infinitely fast shutter fully open for the same extreme time.

Photolithography is a key process in the manufacturing of semiconductor devices, integrated circuits, and microelectromechanical systems (MEMS). It is a photomechanical process used to transfer...

A photomask, also known simply as a mask or reticle, is a key component in the photolithography process used in semiconductor manufacturing and other areas of microfabrication. It is a high-precision...

A process in which a mixture of one or more monomers, plus a catalyst, polymerize under exposure to light radiation. Photopolymerization permits a hologram to be exposed, fixed and reconstructed in...

Photoresist is a light-sensitive material used in photolithography processes, particularly in the fabrication of semiconductor devices, integrated circuits, and microelectromechanical systems (MEMS)....

The photographic recording of data, in binary form, for storage in memory. Exposure is achieved by a cathode-ray tube or by modulating a continuous-wave laser beam with a Kerr cell, both relative to...

A camera equipped with angular scales in altitude and azimuth. The scale readings are imprinted on the film when an exposure is made. The exact point indicated by the scale readings is shown by...

Phototherapy is a medical treatment that involves the use of light to treat various conditions, particularly those related to the skin or mood disorders. There are different types of phototherapies,...

Phototoxicity refers to the harmful effects caused by exposure to light, particularly intense or ultraviolet (UV) light, on living cells or organisms. This phenomenon is often associated with 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...

An interferometric technique for the generation of precision gratings that allows for sequential exposure of small segments in the writing of a large grating, allowing increased intensity that...

A photographic enlarger with a fixed negative plane and a fixed paper plane, often using a roll of paper that is advanced automatically between exposures. The lens is interchangeable to suit a range...

The underexposure caused by the diffraction of light passing through small openings spaced closely together in masks used in photolithography.

The integral of the radiance over exposure time.

Separation of incident laser pulses by several seconds so holographic plates can be changed and sandwiched between the pulses. This technique combines the short exposure time of pulsed holography...