Although the metre is now defined as the path length travelled by light in a given time, the practical laboratory length measurements in metres are determined by counting the number of wavelengths of laser light of one of the standard types that fit into the length, and converting the selected unit of wavelength to metres.

The terminal multiplexer actually contains one wavelength converting transponder for each wavelength signal it will carry.

( Early DWDM systems contained 4 or 8 wavelength converting transponders in the mid 1990s.

As stated above, wavelength converting transponders served originally to translate the transmit wavelength of a client-layer signal into one of the DWDM system's internal wavelengths in the 1550 nm band ( note that even external wavelengths in the 1550 nm will most likely need to be translated, as they will almost certainly not have the required frequency stability tolerances nor will it have the optical power necessary for the system's EDFA ).

In the mid-1990s, however, wavelength converting transponders rapidly took on the additional function of signal regeneration.

A transponder can be made up of two transceivers placed after each other: the first transceiver converting the 1550 nm optical signal to / from an electrical signal, and the second transceiver converting the electrical signal to / from an optical signal at the required wavelength.

Several other properties are also desirable in a good detector scintillator: a low gamma output ( i. e., a high efficiency for converting the energy of incident radiation into scintillation photons ), transparency to its own scintillation light ( for good light collection ), efficient detection of the radiation being studied, a high stopping power, good linearity over a wide range of energy, a short rise time for fast timing applications ( e. g., coincidence measurements ), a short decay time to reduce detector dead-time and accommodate high event rates, emission in a spectral range matching the spectral sensitivity of existing PMTs ( although wavelength shifters can sometimes be used ), an index of refraction near that of glass (≈ 1. 5 ) to allow optimum coupling to the PMT window.

Also known as luminophors, these compounds absorb the scintillation of the base and then emit at larger wavelength, effectively converting the ultraviolet radiation of the base into the more easily transferred visible light.

Suppose company A manufactures down to 130 nm, while company B manufactures down to 22 nm, by extending its photolithography capability through years of successive resolution enhancements, such as wavelength change ( i. e., from 248 nm to 193 nm ), more and more aggressive optical proximity correction, more and more costly phase-shift masks, converting to immersion lithography and finally, implementing double patterning.

* according to another description, transceivers are limited to providing an electrical-optical function only ( not differentiating between serial or parallel electrical interfaces ), whereas transponders convert an optical signal at one wavelength to an optical signal at another wavelength ( typically ITU standardized for DWDM communication ).

Jansky's antenna was an array of dipoles and reflectors designed to receive short wave radio signals at a frequency of 20. 5 MHz ( wavelength about 14. 6 metres ).

As a result, at each end both a transmitter ( to send a signal over a first wavelength ) and a receiver ( to receive a signal over a second wavelength ) will be required.

At Bell Telephone Laboratories Jansky built an antenna designed to receive radio waves at a frequency of 20. 5 MHz ( wavelength about 14. 6 meters ).

3AK's wavelength of 1500 KC could also be seen as a third limiting factor-it was at very end of most contemporary radio dials ; there were still some radio sets that were unable to receive it.

To cover this range antennas generally consist of multiple conductors of different lengths which correspond to the wavelength range the antenna is intended to receive.

The length of the elements of a TV antenna are usually half the wavelength of the signal they are intended to receive.

The light generated by stimulated emission is very similar to the input signal in terms of wavelength, phase, and polarization.

Each wavelength of input beam spectrum is sent into a different direction, producing a rainbow of colors under white light illumination.

A relatively high-powered beam of light is mixed with the input signal using a wavelength selective coupler.

The PMT for the extraordinary beam detects the light intensity of the input beam, while the PEM causes a 1 / 4 wavelength shift that converts linearly polarized light into circularly polarized light.

Dye lasers with an external pump laser can direct enough energy of the proper wavelength into the dye with a relatively small amount of input energy, but the dye must be circulated at high speeds to keep the triplet molecules out of the beam path.

Since the likelihood of response of a given cone varies not only with the wavelength of the light that hits it but also with its intensity, the brain would not be able to discriminate different colors if it had input from only one type of cone.

When light of the resonant wavelength is passed through the loop from input waveguide, it builds up in intensity over multiple round-trips due to constructive interference and is output to the output bus waveguide which serves as a detector waveguide.

where h is the height of the antenna, λ is the wavelength, and I < sub > 0 </ sub > is the RMS input current in amperes.

200 mW average power input ( CW for the Raman ), in a 0. 9NA objective with a center wavelength around 800 nm, constitutes a power density of 26 MW / cm ,< sup > 2 </ sup > ( focus length

As the prism is rotated around a point O, one-third of the distance along face BC, the selected wavelength which is deviated by 90 ° is changed without changing the geometry or relative positions of the input and output beams.

Illustration of the use of interferometry in the optical wavelength range to determine precise positions of stars.

The 1550 nm wavelength is especially important for optical communications because standard single mode optical fibers have minimal loss at this particular wavelength.

The success of this approach to cancer treatment rests on the existence of an ' optical window ' in which biological tissue ( i. e., healthy cells ) are completely transparent at the wavelength of the laser light, while nanoparticles are highly absorbing at the same wavelength.

If applied to optical wavelengths, this manifests itself as a change in the colour of visible light as the wavelength of the light is increased toward the red part of the light spectrum.

They can be found in the power stages of radio and television transmitters, in some high-end audio amplifiers, as detectors of optical and short wavelength radiation, and in sensitive equipment that must be " radiation-hard ".

* In telecommunications, lambda indicates the wavelength in a wavelength-division multiplexing optical communications system.

If the pitch of this twist is on the order of the wavelength of visible light, then interesting optical interference effects can be observed.

Other optical devices, such as spinning mirrors, modulators, filters, and absorbers, may be placed within the optical resonator to produce a variety of effects on the laser output, such as altering the wavelength of operation or the production of pulses of laser light.

The ring in the objective has special optical properties: it, first of all, reduces the direct light in intensity, but more importantly, it creates an artificial phase difference of about a quarter wavelength.

The first is to utilize the shorter wavelength of ultraviolet electromagnetic energy to improve the image resolution beyond that of the diffraction limit of standard optical microscopes.

However it evolved in Generalized MPLS ( GMPLS ) to allow the creation of label-switched paths ( LSPs ) also in not native IP networks, such as SONET / SDH networks and wavelength switched optical network.

Geometrical optics can be viewed as an approximation of physical optics which can be applied when the wavelength of the light used is much smaller than the size of the optical elements or system being modelled.

Modern techniques using excimer laser lithography already print features with dimensions a fraction of the wavelength of light used-an amazing optical feat.

Space-based astronomy is even more important for frequency ranges which are outside of the optical window and the radio window, the only two wavelength ranges of the electromagnetic spectrum that are not severely attenuated by the atmosphere.

For example, the term subwavelength-diameter optical fibre means an optical fibre whose diameter is less than the wavelength of light propagating through it.

* Fraunhofer lines – dark lines in the solar spectrum, traditionally used as standard optical wavelength references

* 380 – 420 nm — wavelength of violet light ( see color and optical spectrum )

* 1. 55 µm — wavelength of light used in optical fibre

The various optical paths AB < sub > j </ sub > will vary by amounts greatly in excess of one wavelength, and so the waves arriving at B will have a large range of phases and will tend to interfere destructively.