Photonics Dictionary: G

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic spectrum. It is composed of layers of gallium, aluminum, and arsenic, hence...

An instrument for detecting or measuring small electric currents.

A small mirror, sometimes plane and sometimes concave, attached to the rotating coil of a galvanometer to cause a spot of light to move along a scale.

The area of optics that deals with the propagation of Gaussian laser beams in free space, or any general medium - i.e. lenses- under the paraxial (small divergence angle) approximations. Gaussian...

1. That branch of optics that illustrates the theory in which q is substituted for sin q in Snell's law. Effective results are achieved if the aperture and field angle are made very small. The...

A noncrystalline, inorganic mixture of various metallic oxides fused by heating with glassifiers such as silica, or boric or phosphoric oxides. Common window or bottle glass is a mixture of soda,...

A furnace used to heat glass materials. It may be a small laboratory-type furnace for small-scale experiments or large enough to hold gas-fired tanks for the commercial mass production of glass....

A thermal radiation detector consisting of a small cell with a blackened plastic front face that bulges slightly when heat is received by it. The bulging tilts a small mirror, which, in turn, varies...

An instrument capable of precise measurements of the Earth's gravity. This permits the detection of small changes in local height that indicate changes in the Earth's crust and subsurface density.

The soft x-rays used in the industrial radiography of materials having too small a range of densities to produce an image with normal x-rays.

A GRIN (gradient index) lens is a type of optical lens that utilizes a gradient in refractive index across its volume rather than having a uniform refractive index like conventional lenses. This...