Photonics Dictionary

The absorption index represents the imaginary component of the complex index of refraction, and not the real component. The imaginary component may characterize the attenuation per unit length...

An optical lens manufactured to control the transmission of light over a specified wavelength range. Low absorption lenses are produced which are anti-reflection coated for UV, VIS and IR wavelengths...

The wavelength or frequency corresponding to an absorption resonance with a given molecular or atomic species. The line spectrum will vary with the element as well as the molecular compound.

A measuring device that uses a light-sensitive cell or detector to determine the amount of light transmitted by a substance.

An absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular wavelength or energy level. It is a distinctive feature in the absorption...

Measures the absorption or sample transmittance over a range of specified wavelengths. Sample may be placed within the device and the transmission measured to an accuracy of given percent. The...

Experimental method of measuring the transmission of a given sample as a function of the wavelength.

Fraction absorption over a specified range of wavelengths.

The measured change in absorption at a single wavelength while altering experimental parameters such as the incident intensity or pulse width.

An accelerometer is a sensor or transducer that measures the rate of change of velocity of an object, or in simpler terms, it measures acceleration. Accelerometers are widely used in various...

The range of angle or solid angle values by which light may enter an optical system.

A curve expressing an optical fiber's total transmitted power as a function of its launch angle at the input.

Impurity in a semiconductor or any other electroluminescent device capable of inducing hole conduction and accepting a valence band electron to produce an acceptor energy level.

The present radiation level within a laser or electromagnetic radiation operating area.

Electromagnetic radiation present upon the open aperture of the source within an operating environment.

Mount attached to a camera or camcorder which allows the user to attach a microphone or flash unit.

A broadband continuum resonator that confines a wide range of wavelengths. From the optical confinement a single wavelength may be released by means of a tuning grating.

Also cellulose acetate film. The emulsion layer applied to the substrate of a photographic surface. The emulsion layer is composed of small particles suspended in gelatin solution.

Optic surface cleaning liquid that may be applied to glass, crystal, dielectric and metal surfaces; however, may not be applied to plastic and polymer materials.

An achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration. Chromatic aberration is an optical phenomenon where different colors of light...

Color correcting; chromatic aberration corrected.

A lens consisting of two or more elements, usually of crown and flint glass, that has been corrected for chromatic aberration with respect to two selected wavelengths. Also known as achromat.

Location on the CIE chromaticity diagram which produces the color white for a given light source at a specified temperature.

Cemented prisms of differing refractive indices which refract incident light and, due to differing refractive indices, will not spatially separate individual wavelengths.

Use of achromatic design; the correction of chromatic aberration; without color or hue (grey, black and white)

The recorded interference pattern formed by the interference of two sound beams.

The optical reconstruction of image information contained in a sound field. First the diffraction pattern, formed by an object irradiated by ultrasonic rays, interferes with a mutually coherent...

The angular change of an incident beam due to vibrational induced refractive index changes within a crystal.

A system designed with a laser as a light source and a means for producing sound waves extending beyond 100 MHz to deflect light efficiently.

Light diffracted by a solid (usually quartz in crystal or fused form) traversed by acoustic waves. If the ultrasonic wavelength is larger than the diameter of the light beam, the diffraction orders...

The altering of lightwaves by acoustic waves in a solid medium.

A device that varies the amplitude and phase of a light beam; e.g., from a laser or by sound waves. Also known as a Bragg cell.

An acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate or control the intensity, frequency, phase, or direction of laser beams. It...

A bulk crystalline optic which permits the propagation of light through a volume of index altered material. The variation in refractive index along the material volume is due to a piezoelectric...

Discipline within optical physics that addresses sound vibration, phonon effects and their influencing behavior within optical elements and systems.

The change in refractive index that occurs as acoustic vibrations are transmitted through an optical material.The index changes are periodic in relation to the frequency, spatial orientation, and...

A thermoplastic or optically transmitting hard plastic produced by applying polymerization initiator and heat to a monomer.

Stimulating light used for the production of energy through photosynthesis, solar cell or other light senstitive device.

That point in the electromagnetic spectrum at which an optical system focuses the most chemically effective rays.

Glass designed to absorb most infrared and ultraviolet radiation while transmitting most of the visible region.

Electromagnetic energy that is capable of producing photochemical activity.