Optical Contact

optical contact

[′äp·tə·kəl ′kän‚takt]
(optics)
Contact between two surfaces in which the surfaces are separated by a distance much less than a wavelength of light, so that interference fringes are not formed.

Optical Contact

 

Surfaces of transparent bodies are said to be in optical contact when the distance between them is of the order of the action range of the molecular forces. Bringing the surfaces together to this distance is called setting them in optical contact. If bodies with equal indexes of refraction are placed in optical contact, light passes through their interface, the optical contact surface, without changing direction. In addition, the reflection coefficient of the optical contact surface is extremely low—from 10-4 to less than 10-7. Clean, well-polished surfaces generally can be brought easily into optical contact, but they then can no longer be moved apart without damage.

Optical contact is also often said to take place when the surfaces of transparent bodies are brought together in such a way that the reflection coefficient of each surface becomes a function of the distance d between the surfaces and decreases rapidly with decreasing d. This phenomenon is particularly evident in the case of total internal reflection, when the reflection coefficient varies as a function of d from 1 to an imperceptibly small value. This effect is used for the intensity modulation of light and for crude spectral separation of the longwave and shortwave parts of radiation.

References in periodicals archive ?
Key players and manufacturers can take note of the point that readily available and efficient off-the-shelf marine penetrator comprises of two electrical and one optical contact. However, customization is a potential trend for the purpose of several multiple electrical and fiber configurations.
Tenders are invited for Automatic Video Based Optical Contact Angle Measuring System
your got a or is it optical Contact LOCKLEY on 234 5553.
The small optical probe allows fast non-contact measurements of very small and hard-to-access geometries, and provides optical contact at two different angles.
In this article, we are aimed at making refractive thicker film (>50 um) which is capable to create optical contact even between nonfiat surfaces at low temperatures.
Videobased, optical contact angle measurement was performed by DataPhysics OCA30 device.
The next time he made optical contact with his assailant was two weeks ago when the muscle-bound Tongan winger strutted his way through the Butts Park Arena door.
Processing capabilities include electron beam lithography capable of sub-20 nm features,[5] optical contact lithography, reactive ion beam etching (RIBE) of metals, dielectrics and compound semiconductors,[6] electron cyclotron resonance (ECR) ion etching, plasma-enhanced chemical vapor deposition (PECVD) of dielectric films, electron beam evaporation of metal films, sputter deposition of metal films and dielectrics, wet chemical etching, electroplating, ion implantation and rapid thermal annealing.
Tenders are invited for Fully Automatic Video Based Optical Contact Angle Measuring System.
Optical contact sense surmounts nonplanarity caused by chip and bonding thickness deviations.
Contract awarded for supply, delivery, installation and commissioning of one unit of optical contact angle instrument complete with software and accessories
Key players operating in the orthokeratology market, as identified in the report, include The Cooper Companies Inc., Euclid Systems Corporation, GP Specialists, Inc., Menicon Co., Ltd., Art Optical Contact Lens, Inc., TruForm Optics, Inc., MiracLens L.L.C., Art Optical Contact Lens, Inc., and Contex, Inc.

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