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Results for “INFRARED MASER”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Optical and infrared masers

High resolution studies of atoms and molecules applied to optical and infrared maser experimentation

Source record↗
NASA NTRS1973

Optical and infrared masers

Ongoing research progress in the following areas is described: (1) tunable infrared light sources and applications; (2) precision frequency and wavelength measurements in the infrared with applications to atomic clocks; (3) zero-degree pulse propagation in resonant medium; (4) observation of Dicke superradiance in optically pumped HF gas; (5) unidirectional laser amplifier with built-in isolator; and (6) progress in infrared metal-to-metal point contact tunneling diodes.

Source record↗
NASA NTRS1974

Infrared maser emission from interstellar hydroxyl molecules

The energy structure and transition rates of the OH radical were studied in rotational and vibrational energies to provide the basis for studies of the population distributions under various exciting mechanisms. The absorption of ultra-violet or near infrared radiation which might explain the microwave emission was examined, as well as the absorption of low temperature blackbody radiation and collisions with molecular hydrogen. The results of the population studies were applied to the transfer equation, and a model of a uniform spherical cloud of OH was used with the pumping process which occurs uniformly throughout the region. The emission is unsaturated and the intensity is an exponential function of the size of the cloud for high pumping rates, and the region of unsaturated emission shrinks for lower pumping rates until the entire region is saturated, the intensity then becoming a linear function of the size of the emitting cloud.

Pelzmann, R. F., Jr.↗
NASA NTRS1975

Far infrared maser communications technology

An optically pumped FIR laser was constructed and tested. Optimum operating conditions were determined with CH3OH as the lasing medium. The laser was found to operate equally well with flowing gas or in a sealed off configuration. The FIR cavity stability and pump laser stability were found to have significant problems. The absorption coefficient per unit pressure of 1-1 difluoroethylene at the P(22) and P(24) lines of the 10.4 micron CO2 band was measured. The FIR line pumped by P(22) occurs at approximately 890 microns, which may be in an atmospheric transmission window. It was found that significant Stark tuning of absorption lines of methanol and 1-1 difluoroethylene can be accomplished, even at the usual 100 to 300 mTorr operating pressures of FIR lasers. This means that the use of Stark tuning may enable more effective use of pump laser output.

Claspy, P. C.↗
NASA NTRS1974

Time variation of the H2O maser and infrared continuum in late-type stars

Observations of the variability of the 1.35-cm H2O and 2.2-micron emission from eight late M stars are described. A comparison of the microwave and infrared variations is of interest because the bulk of the stellar energy is radiated in the near-infrared and because at least one theory (Litvak 1969) hypothesizes near-infrared maser pumping via the 2.7-micron H2O vibration-rotation band. Variations at the two wavelengths appear to be correlated and possible explanations for this correlation are discussed.

Schwartz, P. R.↗
NASA NTRS1992

Mid-infrared imaging of Orion BN/KL - Astrometry of IRc2 and the SiO maser

Array images of Orion BN/KL at nine midinfrared (5-20 microns) wavelengths have revealed a subarcsecond structure near IRc2 which provides new constraints on the relationship between IRc2 and the Orion SiO maser. The infrared source positions have been improved, and IRc2 is found to be displaced 0.8 +/- 0.2 arcsec (at least 400 AU) from the SiO maser, an order of magnitude greater than the separation assumed in the current maser model. The SiO maser and the IRc2 midinfrared source may be physically independent objects. There are indications that IRc2 is eroded on the south side adjacent to the SiO/H2O maser cluster, suggesting that another luminous object near IRc2, most likely a stellar object associated with radio continuum point source 'I', is the host for the Orion SiO maser.

Gezari, Daniel Y.↗
NASA NTRS1975

Vibrationally excited SiO - A new type of maser source in the millimeter wavelength region

The recently discovered strong emission lines at 86.24 GHz from the J = 2-1 rotational transition of SiO in its first excited vibrational state have been found to be a maser source associated with infrared stars. Twelve maser sources have been detected, and almost all are late M-type Mira or semiregular variables. Many of the known OH/H2O/IR sources are also SiO maser sources, and good velocity correlations between SiO and H2O emission profiles were found. Characteristics of these new SiO maser sources are discussed.

Kaifu, N.↗
NASA NTRS1981

Far-infrared observations of the H2O masers in NGC 281, NGC 2175, and S255/257

The H2O masers in NGC 281, NGC 2175, and S255/257 have been observed in four far-infrared bands from 40-140 microns with 30 arcsec and 50 arcsec beams. The far-IR positions are consistent with the H2O positions. The far-IR sources have luminosities of 10 to the 4 + or 0.5 solar luminosities, dust temperatures of 36-50 K, H densities greater than 10 to the 4.5, and apparent masses of 12-120 solar masses.

Wright, E. L.↗
NASA NTRS1981

Shock waves, atmospheric structure and mass loss in Miras

Large amplitude shock waves are observed to be present in the atmospheres of the Mira variables: spectral line doubling with Delta v 30 km/s is present in infrared spectra. Even the visible spectra contain some evidence for such shocks. These shocks are sufficiently large to clearly dominate the energy balance of the atmosphere. Mira variables also show symptoms of substantial mass loss rates: they are strong maser and infrared continuum sources and have strong circumstellar absorption features. The pulsation induced shocks which are seen to be present are obvious suspects for causing or enhancing the mass loss from these stars. The Miras thus present an ideal case for the study of dynamical effects on atmospheric structure, since both the dynamics and the results are clearly observable. The results are given of calculations of the thermalization and cooling of the shock heated material passing through shock fronts whose properties were selected to be consistent with both the isothermal models and the spectroscopic observations.

Willson, L. A.↗
NASA NTRS1981

The energetics of molecular clouds. III - The S235 molecular cloud

The molecular cloud associated with the S235 H II region has been studied by means of molecular lines and near-infrared observations. The cloud consists of two components, one of which partly surrounds the S235 H II region. The other component contains a dense, hot region of active star formation, marked by self-reversed CO profiles, compact H II regions, masers, and infrared sources. From the molecular line data, the size and mass of the two components are estimated to be 6-8 pc and 3000-4000 solar masses. More detailed studies near the region of active star formation yield estimates of density (approximately 200,000-500,000/cu cm) and the abundances of H2CO, HCO(+), HCN, and (C-13)O. Analysis of the energetics suggests that the cloud is heated by the exciting star of S235 and by the exciting stars of the compact H II regions. Assuming that the gas is heated by collisions with warm dust grains, the far-infrared luminosity has been predicted. The observations of far-infrared emission are in reasonable agreement with predictions.

Evans, N. J., II↗
NASA NTRS1974

Infrared pumping processes for SiO masers

The J = 2 to 1 transition of the first excited vibrational state (v = 1) Si(28)O(16) has recently been shown to produce maser amplification near 86,245 MHz in Orion A and in several stars. Two possible pumping mechanisms are proposed for such masers. One involves the near coincidence between the frequencies of the 1-0 (RO) and 3-2 (R18) transitions in Si(28)O(16). The other requires emission by SiO and reabsorption without the necessity for an accidental frequency coincidence. Each of these types of mechanisms may occur for other transitions of molecules in a medium illuminated by intense infrared radiation, or with strong temperature gradients.

Geballe, T. R.↗
NASA NTRS1966

Semiconductor laser amplifier.

IR GaAs laser amplifier with gains as high as 2000, output powers of 150 mw and saturation occurring with current increase at low light levels

POWER GAIN↗