Sentences with phrase «for photon emitting»

No target class reveals compelling evidence for photon emitting sources in the EeV energy regime.

Not exact matches

These results indicate that the polymers studied have large cross sections for stimulated emission, that population inversion can be achieved at low pump energies, and that the emitted photons travel distances greater than the gain length within the gain medium.

They have indeed discovered a compact galaxy emitting a large number of ionizing photons, which are responsible for this transformation of the Universe.

The instruments that search for these products of dark matter annihilation were conceived as telescopes or detectors to look at particles and photons emitted by galaxies and the exotic objects that lie within them.

«The supercomputer can run for a day, but then to post-process the data and to assemble it to determine which electron emitted what photon, that was pretty demanding too.

But for a black hole of 1012 kilograms, which is about the mass of a mountain, it is 1012 kelvins — hot enough to emit both massless particles, such as photons, and massive ones, such as electrons and positrons.

The approach would involve combining light - emitting diodes (LEDs) with a superconductor to generate entangled photons and could open up a rich spectrum of new physics as well as devices for quantum technologies, including quantum computers and quantum communication.

«A usual light source such as an LED emits photons randomly without any correlations,» explains Hayat, who is also a Global Scholar at the Canadian Institute for Advanced Research.

Metaphorically speaking, the lattice acts as a magnet for photons, extracting them (white arrow) from the light - emitting region before they can be reabsorbed.

It absorbs and reemits some light from the surface, but it also emits its own UV light, making it difficult to identify where the photons originated, says Bart de Pontieu, the science lead for IRIS at the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, Calif..

Experimental results show that almost 40 % of the photons are easily collected with a very simple optical apparatus, and over 20 % of the photons are emitted into a very low numerical aperture, a 20-fold improvement over a freestanding quantum dot, and with a probability of more than 70 % for a single photon emission.

In the same way large antennas on rooftops direct emission of classical radio waves for cellular and satellite transmissions, the nano - antenna efficiently directed the single photons emitted from the nanocrystals into a well - defined direction in space.

But since information for quantum communication based on photonics is encoded in a single photon, it is necessary to emit and send them one at a time.

The ripples are so large that by the time the photons detected by COBE were emitted, the Universe was simply not old enough for a light signal to have crossed from one side of a COBE ripple to the other.

For example, from laboratory experiments we can determine the amount of amino acids produced per photon of ultraviolet radiation, and from our knowledge of stellar evolution we can calculate the amount of ultraviolet radiation emitted by the sun over the first billion years of the existence of the earth.

Of course, for every photon the atom absorbs, it must emit one.

«By chemically modifying the nanotube surface to controllably introduce light - emitting defects, we have developed carbon nanotubes as a single photon source, working toward implementing defect - state quantum emitters operating at room temperature and demonstrating their function in technologically useful wavelengths,» said Stephen Doorn, leader of the project at Los Alamos and a member of the Center for Integrated Nanotechnologies (CINT).

By emitting light only one photon at a time, one can then control the photons» quantum properties for storage, manipulation and transmission of information.

Unlike parametric down - conversion techniques, quantum dots allow for photons to be emitted only one at a time and on demand, crucial properties for quantum computing.

But in the process of his research, Miller, along with Yablonovitch, realized that solar cells which emitted more photons without losing thermal energy made for a more efficient cell.

A point to keep in mind - although PA - FPs are vastly improved over the conventional FPs for super-resolution imaging, they still do not emit the large number of photons achievable with photoswitchable dyes.

The processes (absorption of light, collisional energy transfer and emission) can be separated because the average time that an isolated CO2 molecule takes before it emits a photon is much longer that the time for collisional de-excitation (~ tens of microseconds at atmospheric pressure, less, higher in the atmosphere).

The frequency at which photons are emitted or absorbed is small relative to the rate of energy redistribution among molecules and their modes, so the fraction of some molecules that are excited in some way is only slightly more or less than the characteristic fraction for that temperature (depending on whether photons absorption to generate that particular state is greater than photon emission from that state or vice versa, which depends on the brightness temperature of the incident radiation relative to the local temperature).

What I'm saying is that TOA, as far as radiative energy is concerned, for CO2 or other IR absorbing gas, is effectively the altitude where the chance that a photon will be absorbed, and emitted back in a direction that will lead it to being absorbed again by a molecule in the atmosphere, becomes negligible.

So for a particular type of photon, emitted intensity (I.emitted) into a direction = absorbed intensity (I.absorbed) from that direction if the temperature of the non-photons is equal to the brightness temperature of the incident radiant intensity (I.incident).

So basically thinking of a «global absorption» exp -LRB-- tau) throughout the atmosphere is not particularly relevant: it holds for the initial photons emitted for the ground, but not for the total amount of photons.

But when optical thickness gets to a significant value (such that the overall spatial temperature variation occurs on a spatial scale comparable to a unit of optical thickness), each successive increment tends to have a smaller effect — when optical thickness is very large relative to the spatial scale of temperature variation, the flux at some location approaches the blackbody value for the temperature at that location, because the distances photons can travel from where they are emitted becomes so small that everything «within view» becomes nearly isothermal.

At any particular frequency (wavelength), Beer's law does allow and call for eventual saturation in some conditions, which would not be logarithmic but rather asymptotic, and would occur when, at the point considered, photons reaching that point are being emitted from places all at the same temperature as at the point considered.

Then the temperature of the whole population of molecules in some volume is approximately the same temperature as the molecules that are responsible for emitting and absorbing photons.

Re 1 Timothy — the idea of an effecive emitting altitude is a useful though rough approximation — the photons leaving for space originate over a range of altitudes at any given frequency (wavelength), and that range shifts over different wavelengths.

More photons are emitted to the fourth power of ANY increase in temperature, for whatever reason the increase in temperature takes place.

The overall temperature of the emitting body has to adjust upward to maintain an energy balance to compensate for the photon wavelength bands that get filtered by GHG cross-sectional absorption.

For all the talk of how many photons are emittied or not emitted, again no one is presenting papers showing reasonable measurements of the actual energy transfer that happens during these interactions.

-- For the photons of interest, it is only the GHGs that are absorbing / emitting: if gas molecules don't have quantum transitions with the right energy differences, they can't interact with the photons.

For each «greenhouse» gas there must be some altitude at which half the photons emitted going straight up escape to outer space.

This looks like heating to me, and, the temperature is controlled by the variance in the rate of absorbed and emitted IR photons for any small volume.

Some might argue that the term «re-radiate» should be reserved for cases where a molecule or atom absorbs a photon of a given energy, and later emits a photon of the same energy, as the excited state returns to normalcy.

Gerlich and Tscheuschner, despite their apparent mastery of the mathematics of radiative transfer, don't know the difference between gross and net radiative flux, and they are apparently unaware of the concept of causality in an Einsteinian framework — a molecule of CO2 emitting a photon in a random direction can't know if there is a (cooler or warmer) surface in the direction of emission until time has elapsed for the photon to travel to the surface and back, and has no mechanism to remember from one photon to the next whether there was a source of photons in that direction, or what the apparent temperature of the emitter was.

High spontaneous emission quantum efficiency, is important for photon number squeezed light, diode lasers, single ‐ mode light ‐ emitting ‐ diodes, optical interconnects, and solar cells.»

I guess I am asking, does the interior of the cube above actually have photons bouncing about from side to side being emitted and reabsorbed, always and forever, or are there no photons at all radiated inside that cube (but from the very tiny leak from the never absolutely perfect insulation, ok, a few photon every know and then for that leak)?

* The ground is a little warmer than the atmosphere, so that factor will mean some more photons going up than down (but since the back radiation is mostly from low layers, the atmosphere emitting the back radiation will not be that much cooler than the land so the effect from temperature will not be TOO great) * The ground is close to a black body for IR (emissivity = 1 for all IR frequencies), but the atmosphere has bands where it does not emit or absorb well (emissivity ~ 0) and other bands where it does emit or absorb well (emissivity ~ 1).