Photonics Dictionary

A salt of formic acid that can be used to enhance the photosensitivity of silver halide crystals.

Transformation of an image, such as a change in position or scale, that does not alter the linearity of the original image.

Theoretical calculation of the cross section for a nuclear reaction given in the vicinity of a single resonance level in the compound nucleus.

A spatial light modulator consisting of a metallized polymer film stretched over an array of metal-oxide semiconductor field-effect transistors (MOSFETs). Each mirror element in the film can be...

Any of the constants that relate the tendency of the director to remain parallel to restoring torques throughout the media. The three constants of importance in liquid crystal displays are: splay --...

The exact mathematical description of the interactions of matter and intense electromagnetic fields, such as those that occur when laser sources are used to excite flame gases for spectroscopic...

A mathematical transformation used in image and video compression that changes two-dimensional representation of data into data defined by the frequency content. Adapted in JPEG and MPEG standards.

All formulas that present the index of refraction as a function of a wavelength of electromagnetic radiation. Also called dispersion equation, Cauchy formula, Hartmann formula.

A mode of laser printing in which each pixel is printed four times, providing sharper lines and a continuous tone from one-quarter the amount of image data, compared with single-raster output.

An electrochemical process of metal fabrication using an electrolyte, an anode to supply the metal, and a control of the electrical current and of the deposit of metal on the matrix of a reflector.

A fiber optic preform is a cylindrical glass rod or tube used as the starting material for manufacturing optical fibers. It serves as the precursor from which optical fibers are drawn. The process of...

A wide-field multiobject spectroscopy system used in astronomy, in which a bundle of low-loss optical fibers positioned on the target images is rearranged at its other end into a linear array along...

A transformer that is designed to regulate the amount of current that passes through an electron tube's filament.

A hologram formed by the recording of a plane object situated in the focal plane of a lens so that each object gives rise to a parallel beam of light incident on the plate. A collimated reference...

An instrument using a Michelson interferometer, a beamsplitter, two plane mirrors and a detector to give Fourier analysis of the detector signal to provide the desired spectrum.

Any of the various methods of decomposing a signal into a set of coefficients of orthogonal waveforms (trigonometric functions).

Freeform mirrors refer to reflective optical components that deviate from traditional symmetric or rotationally symmetric shapes, such as spheres or paraboloids. Unlike conventional mirrors, which...

Freeform optics refers to the design and fabrication of optical surfaces that do not follow traditional symmetric shapes, such as spheres or aspheres. Unlike standard optical components with...

A very high bandwidth communication line often used in fiber optics.

The processing of an image or portion of an image by transform coding and analysis. Fourier, Hadamand, Kronecker and Eigenvector transforms are applicable to image transformation.

A device consisting of two optical systems in which two signals are simultaneously transformed to produce their spectra, and these spectra are multiplied and inversely transformed to produce the...

Lens which, by altering the phase, efficiently images through a holographic process.

A computer-generated kinoform used for data processing because of its use of incoherent light and its wide field of view, which facilitates parallel processing of two-dimensional data.

A hologram formed without lenses and with the object and reference points sharing the same plane. In the initial recording, each object point produces fringes having one spatial frequency across the...

One class of nonlinear space-invariant transformation processes used for processing convolved and multiplied signals.

A form of an element that cannot demonstrate optical activity as a result of dextrogyrate and levogyrate effects that are balanced contrary to each other in a structure. In essence, meso form...

The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial domain representation of an image into its corresponding frequency domain...

A technique for detecting and measuring atmospheric pollution, in which an oscillating mirror directs half the incoming light to a transducer that controls amplitude and frequency, and the resulting...

Noise created by patterns imaged on a CCD surface. Pixel sensitivity is altered by responsivity during illumination.

A manufacturing process used to construct substrates for large optical components. Used with IR materials, planform bonding permits the joining of several smaller pieces to be used in place of a...

A glass structure from which an optical fiber waveguide may be drawn.

A series of capacitors and inductors connected to the flashlamp in a pumped Nd:YAG laser system in order to regulate the pulse shape of the current delivered to the lamp at a given operating voltage.

The transform defining that, if a reference beam is a divergent spherical wavefront, then the reconstructed image will be the equivalent of the near-field diffraction pattern of the object. Also...

When splitting the output of a single optical fiber into two or more fibers, the difference in the maximum loss between any two channels.

A platform mount used to hold sensitive optical instruments immobile.

The graph of the oscillating variations composing the wave of a video signal.

The Fourier series representation of a two-dimensional periodic field, assuming that the original image is periodic both horizontally and vertically.

A color space in which equal distances represent equal visually perceived color differences.

In a cathode-ray tube, the region wherein a display on the tube keeps 70 percent or more of its luminance at the center of the viewing area.

Array used in coded-aperture imaging experiments with two-beam CO2 lasers that provide an artifact-free process, faithful reproduction of the true image, and more photon collection than the pinhole...

A device designed to measure the amplitude and frequency of the elements in a complex waveform.

An oscilloscope used to survey the waveform of a video signal.

The graph of the oscillating variations making up a wave, relative to time.