An electronic instrument for emitting, modulating, transmitting, or sensing light. The effects electricity has on optical materials; such as, a change in refraction or birefringence which is the optical property of a material that causes the polarizations of light to travel at different speeds.

1. A pattern of double refraction exhibited by certain refracting materials when exposed to an electric field.
2. Birefringence induced by an electric field or an optical property in which a single ray of unpolarized light splits into two components traveling at different velocities and in different directions.

In birefringent materials either the separation between neighboring atomic structural units is different in different directions, or the bonds tying such units together have different characteristics in different directions.

1. That branch of character recognition concerned with the automatic identification of handwritten or printed characters by any of various photoelectric methods.
2. A method for the machine-reading of typeset, typed, and, in some cases, hand-printed letters, numbers, and symbols using optical sensing and a computer.

The light reflected by a printed text; for example, is recorded as patterns of light and dark areas by an array of photoelectric cells in a optical scanner.

The effect wherein certain transparent dielectrics (materials which are poor conductors of electric current) become doubly refracting (bending of electromagnetic waves as they pass between materials with different refractive indices or magnitude of some physical effect) when placed in an electric field.

A biometric technology that provides for the scanning, comparison, and identification of fingerprints without the traditional need for ink and paper.

An optical scanning and recognition system is used in conjunction with a matching system to enable efficient authentication for secure spaces and devices. Like other finger scanning technologies, electro-optical fingerprint recognition makes it possible to quickly and accurately compare a given fingerprint image to thousands of stored images.

Electro-optical fingerprint scanners are generally designed to be portable, easy to use, and physically rugged. The devices are becoming more widely used as an alternative to passwords for consumer electronics or as part of a two-factor authentication system where more stringent security is required.

The fingerprint is optically scanned directly from the finger and the resulting image is focused onto a small chip. The chip converts the focused image into a digital file that can be processed, stored, and compared with other fingerprint images.

The high-resolution digital images can be processed like any other scanned images, eliminating problems caused by aliasing (also called jaggies) and making it possible to quickly compare a fingerprint image with other fingerprint images in a large database.

In robotics, a camera or other deice at the end of a robot's arm which is used to take hold of or to manipulate an object which is being worked on.

A material which is capable of transforming electrical information into optical information or performing some optical function in response to an electric signal.

One example is lead lanthanum zirconte titanate, a transparent ferroelectric ceramic whose optical properties can be changed by an electric field.

In lasers, such materials can be used for beam deflection, beam modulation, and Q switching (Quality switch or an optical valve in a laser that prevents light from transmitting outside the resonating cavity).

The Q switch allows for the build-up of energy before it is switched open to allow light to move out.

An optical modulator in which a Kerr cell, an electro-optical crystal, or other signal-controlled electro-optical device is used to modulate the amplitude, phase, frequency, or direction of a light beam.

With a laser beam, modulating frequencies well into the gigahertz range are possible.

A Kerr cell is an optical device consisting of a transparent cell with two electrodes between two polarizing media which passes light only if the two planes of polarization are parallel and it is used as a high-speed shutter or to modulate a laser beam.

A shutter which uses a Kerr cell to modulate a beam of light.