Photonics Dictionary: I

A desklike apparatus with an opal glass surface illuminated from beneath by fluorescent tubes. It is equipped with roll holders for aerial films and a low-power microscope or some form of...

Generally, a rotatable table with scales marked in degrees. The fiducial marking also may be a vernier scale. The same scheme is applied to linear movement. Such devices are often applied to...

In semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from group III and group V of the periodic table. More specifically, these...

In the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within the material that deviate from its regular or intrinsic composition. These...

An exposure meter designed to measure the light striking an object and used at a suitable location in a scene.

An InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the near-infrared (NIR) spectrum. InGaAs is a semiconductor material that is...

Indium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the III-V group of semiconductors, where elements from groups III and V of the...

An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating infrared (IR) radiation within the infrared spectrum. These lenses are used in...

A spectrophotometer having a prism or, more frequently, a grating for the study and recording of infrared spectra. It usually consists of a radiation source such as a Nernst glower, a monochromator,...

An InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a combination of indium (In), gallium (Ga), and arsenic (As). The term InGaAs...

The use of a small ultrastable master oscillator (a diode-pumped Nd:YAG laser) to achieve single-frequency operation of a large pulsed Nd:YAG host laser, providing improved bandwidth and temporal...

A hollow sphere coated internally with a white diffusing material and provided with openings for incident beam, specimen and detector used for measuring the diffuse reflectance or transmittance of...

The separation between the exit pupils of a binocular instrument. This usually is adjustable so that it can be set equal to the observer's interocular distance, a normal range being from 55 to 75 mm.

A photodetector composed of a photoconductive material that, when exposed to radiation, conducts without the aid of added impurities and does not have to be cooled to the level of extrinsic material....

The law stating that the illuminance (or irradiance) from a point source varies as the inverse square of the distance between the source and the receiver.

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized gas. The gases are electrically excited in a container called a plasma tube,...

Ion-beam sputtering (IBS) is a physical vapor deposition (PVD) technique used for depositing thin films onto substrates. It involves bombarding a target material with a beam of energetic ions,...

A mechanical device designed to smoothly vary the effective diameter of a lens, thereby controlling the amount of light allowed through.

The adjustable membrane located just in front of the crystalline lens within the eye. The iris gives the eye its color. See also iris diaphragm.