Measurement of atmospheric surface pressure with a satellite-borne laser.
Atmospheric surface pressure measurement with satellite-borne laser operating in oxygen A band by determining absorptance inside and outside of bands
Singer, S. F.↗
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Results for “laser operations”
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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Laser altimeter
Ruby laser operating at 6943 angstroms at the heart of an electronic ranging system provides a highly accurate range measurement to an extremely small area.
Kolker, M.↗
Diffraction-limited GaAs laser with external resonator
GaAs injection laser operated with external optical resonator for diffraction-limited radiation, considering peak power and quantum efficiency
Edmonds, H. D.↗
DF-CO sub 2 and HF-CO sub 2 continuous-wave chemical lasers
Continuous wave chemical laser operation in carbon dioxide pumped by vibrational energy released from DF and HF molecular formation
Cool, T. A.↗
HBr-CO2 continuous-wave chemical laser
Continuous wave chemical laser operation at 10.6 micron in carbon dioxide pumped by vibrational energy from hydrogen atoms and bromine molecules reaction
Cool, T. A.↗
HCl, HF, and DF partially inverted CW chemical lasers
CW chemical lasers operation from partially inverted transitions of HCl, HF and DF molecules in subsonic flow
Cool, T. A.↗
Simultaneous intracavity frequency doubling and mode locking in a Nd-YAG laser
Nd-YAG laser operation with simultaneous intracavity frequency doubling and mode locking, observing mode-locked pulse lengthening and circulating power decrease
Hitz, C. B.↗
Lunar laser ranging data deposited in the National Space Science Data Center: Filtered observations for September 1969 through June 1970 and unfiltered photon detections for July through December 1970
The technique of laser ranging to a reflector fixed on the lunar surface is discussed. The causes for initial low rate of data acquisition are explained. The documentation to be used in conjunction with the deposition of the filtered data in the National Space Science Data Center are documented. Filtered data obtained during laser operations between the McDonald Observatory and the reflector at Tranquility Base during the interval September 1969 through June 1970 are presented. The unfiltered photon detections for the succeeding six months are examined.
Mulholland, J. D.↗
Erase-mode recording characteristics of photochromic CaF2, SrTiO3, and CaTiO3 crystals.
Erase-mode optical recording characteristics of photochromic crystal wafers of CaF2:La,Na; CaF2:Ce,Na; SrTiO3:Ni,Mo,Al; and CaTiO3:Ni,Mo have been measured. An argon laser operating at 5145 A was used for both optical recording and optical readout. Sensitometric curves of optical-density change versus logarithm of exposure are shown for a number of erase-beam intensities between 0.2 mW/sq cm and 2 W/sq cm. In this range, time-intensity reciprocity holds for the CaF2 materials but fails for the titanates, particularly at low intensities. The dependences of sensitivity, gamma, and maximum transmission contrast ratio on wafer thickness and material are discussed. Wafers of SrTiO3, CaTiO3, and CaF2 exhibiting approximately equal maximum contrast ratios have relative sensitivities approximately in the ratio 5:2:1, respectively, at an erase intensity of 1 W/sq cm.
Duncan, R. C., Jr.↗
Transmitter and receiver antenna gain analysis for laser radar and communication systems
A comprehensive and fairly self-contained study of centrally obscured optical transmitting and receiving antennas is presented and is intended for use by the laser radar and communication systems designer. The material is presented in a format which allows the rapid and accurate evaluation of antenna gain. The Fresnel approximation to scalar wave theory is reviewed and the antenna analysis proceeds in terms of the power gain. Conventional range equations may then be used to calculate the power budget. The transmitter calculations, resulting in near and far field antenna gain patterns, assumes the antenna is illuminated by a laser operating in the fundamental cavity mode. A simple equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn which display the losses in antenna gain due to pointing errors and the cone angle of the outgoing beam as a function of antenna size and central obscuration. The use of telescope defocusing as an approach to spreading the beam for target acquisition is compared to some alternate methods.
Klein, B. J.↗
A spectroscopic study of CW chemical lasers.
A subsonic transverse-flow chemical laser has been instrumented to permit measurements of vibration-rotation state populations and laser output spectra under flow conditions typical of present CW hydrogen halide laser operation. Measurements are presented for the F + HI, F + HBr, F + CH4, F + HCl, F + H2, Cl + HI, and Cl + HBr atom-exchange reaction systems. CW operation was found to be characterized by relatively modest departures from Maxwell-Boltzmann vibrational energy distributions at all stages of reaction in contrast to pulsed operation based on similar reactions.
Rosen, D. I.↗
Pulsed writing of solid state holograms.
The pulsed writing of volume holograms in lithium niobate is reported, both with 200-nsec and 20-nsec duration pulses. This information is of particular interest in high capacity information storage applications since it indicates that writing times at least as short as 20-nsec are readily possible. A series of pulses was used in each case, and the diffraction efficiency was monitored using a He-Ne laser operating at 6328 A and aligned to its corresponding Bragg angle.
Gaylord, T. K.↗
Short-range laser obstacle detector
Detector, designed for slow-moving vehicle to explore surface of Mars, will automatically divert vehicle from obstacles as small as 0.5 m in its path. Detector comprises injection laser operating in pulse time-delay measurement, or radar, mode. It is capable of scanning area extending from few meters to approximately 30 m.
Kuriger, W. L.↗
The optical pumping of alkali atoms using coherent radiation from semi-conductor injection lasers and incoherent radiation from resonance lamps
An experimental study for creating population differences in the ground states of alkali atoms (Cesium 133) is presented. Studies made on GaAs-junction lasers and the achievement of population inversions among the hyperfine levels in the ground state of Cs 133 by optically pumping it with radiation from a GaAs diode laser. Laser output was used to monitor the populations in the ground state hyperfine levels as well as to perform the hyperfine pumping. A GaAs laser operated at about 77 K was used to scan the 8521 A line of Cs 133. Experiments were performed both with neon-filled and with paraflint-coated cells containing the cesium vapor. Investigations were also made for the development of the triple resonance coherent pulse technique and for the detection of microwave induced hyperfine trasistions by destroying the phase relationships produced by a radio frequency pulse. A pulsed cesium resonance lamp developed, and the lamp showed clean and reproducible switching characteristics.
Singh, G.↗
Optical antenna gain. I - Transmitting antennas
The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM-00 mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.
Klein, B. J.↗
Losses introduced by tilting intracavity etalons
An approximate analytical expression and numerical results for the on-resonance losses caused by tilting an intracavity etalon are given, when the laser operates in the zero-order Gaussian mode.
Leeb, W. R.↗
A frequency doubled pressure-tunable oscillator-amplifier dye laser system
A tunable high-repetition-rate oscillator-amplifier dye-laser system is reported. The dye laser described was longitudinally pumped with the second harmonic of a Nd-YAG laser operating at 10 Hz. Using three Faraday-Perot etalons and pressure tuning, a maximum fundamental output power of the order of 6 MW with a corresponding spectral width of less than 0.003 nm at 564 nm was obtained. The fundamental at 564 nm was frequency doubled to give a maximum power level of 0.6 MW of second-harmonic output power with a spectral width less than 0.0015 nm at 282 nm. Frequency stability could be maintained to within approximately 15% of the line-width.
Moriarty, A.↗
Discharge stabilization studies of CO laser gas mixtures in quasi-steady supersonic flow
Experiments were conducted to study the applicability of a double discharge stabilization scheme in conditions appropriate for high energy CO lasers in supersonic flows. A Ludwieg tube impulse flow facility and a ballasted capacitor bank provided essentially steady flow and discharge conditions (d.c.) for times longer than ten electrode length-flow transit times. Steady, arc-free, volume discharges were produced in a Mach 3 test cavity using an auxiliary discharge to stabilize the main discharge in N2 and He/CO mixture. A signigicant result is the lack of observed plasma E/N changes in response to auxiliary discharge current changes. Also, where glow discharges were obtained, the energy loading achieved was very much less than the threshold level required for laser operation.
Srinivasan, G.↗