Photonics Dictionary

The observation and measurement of the flatness of a mirror surface by contacting an optical flat with the mirror. The process generally is done before coating so as not to damage the delicate coated...

A technique used for noncontact inspection of semiconductor wafers. The material is illuminated by an excitation source that stimulates photoluminescence; the resulting spectrum is analyzed, yielding...

A noncontact form of electromodulation in which modulation of the electric field is caused by photo-excited electron-hole pairs from a pump source.

A noncontact sensor used in the remote measurement of position, speed or other variables of moving parts.

A noncontact, nondestructive method of measuring defects in thin composite materials, using a xenon flashtube to generate heat in a sample. A thermal imaging system detects differences in the rates...

A self-interference effect that generates random patterns; secondary speckle pattern (SSP) typically occurs in diffuse reflections of a laser on paper, white paint or rough surfaces. By tracking both...

A measuring instrument used for surface profiling and quantifying the roughness of a material. The stylus is placed on the surface of the material at a given contact force, then is moved laterally...

Thermography is a technique that involves the use of an infrared imaging device, called a thermal camera or infrared camera, to detect and visualize the infrared radiation emitted by objects. This...