Diode laser infrared heterodyne spectrometer
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Hillman, J. J.↗
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Diode laser spectrum of nitric acid at 5.9 microns and carbonyl sulfide frequency/wavelength standards for calibration of nitric acid bands both at 5.9 and 11.4 microns
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Wells, J. S.↗
Time evolution of pulsed far-field patterns of GaAlAs phase-locked laser-diode arrays
The time evolution of pulsed far fields from commercially available gain-guided phase-locked arrays has been studied and compared to experimental results previously obtained by streak camera measurements, and to predictions of coupled-mode theories developed for index- and gain-guided arrays. Although phase locking is evident by 100 ps into the drive pulse, stable operation in a fixed superposition of array modes is not achieved until 1-2 ns after the drive pulse has stabilized.
Forrest, Kathrine A.↗
Tunable diode laser measurements of linestrengths and line positions in the HNO3 nu3 band near 1335/cm
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May, Randy D.↗
NO2 heterodyne frequency measurements with a tunable diode laser, a CO laser transfer oscillator and CO2 laser standards
Heterodyne frequency measurements have been made on selected groups of nitrogen dioxide rovibronic transitions between 1580.8 and 1650.7/cm. The groups are separated by 7 to 10/cm, and the intent is to provide a limited (and interim) calibration table for the region. In addition to a table of measured frequencies in the region, figures of spectra in the vicinity of the measured lines are included to provide a map for identifying the transitions measured.
Zink, L. R.↗
Self- and foreign-gas broadening of ethane lines determined from diode laser measurements at 12 microns
Self- and foreign-gas broadening of ethane lines have been measured in the nu9 band at 12 microns. A coefficient of 0.125 per cm atm was determined for self broadening. Foreign-gas broadening coefficients determined are (in per cm atm) 0.090 for N2, 0.069 for He, 0.068 for Ar, 0.108 for H2, and 0.096 for CH4. Results are given for a sample temperature of 296 K.
Blass, W. E.↗
Line strength measurements in the nu1-fundamental band of (N2-14)O-16 using a tunable diode laser
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Varanasi, P.↗
30 Hz-linewidth, diode-laser-pumped, Nd:GGG nonplanar ring oscillators by active frequency stabilisation
A heterodyne linewidth of less than 30 Hz for the beatnote between the outputs of two 282 THz Nd:GGG nonplanar ring oscillators (NPROs) is reported. The lasers were independently locked to adjacent axial modes of a high-finesse interferometer. The remnant frequency noise appears to be dominated by free spectral range fluctuations in the reference interferometer rather than by residual laser noise.
Day, T.↗
Diode laser satellite systems for beamed power transmission
A power system composed of an orbiting laser satellite and a surface-based receiver/converter is described. Power is transmitted from the satellite to the receiver/converter by laser beam. The satellite components are: (1) solar collector; (2) blackbody; (3) photovoltaic cells; (4) heat radiators; (5) laser system; and (6) transmission optics. The receiver/converter components are: receiver dish; lenticular lens; photocells; and heat radiator. Although the system can be adapted to missions at many locations in the solar system, only two are examined here: powering a lunar habitat; and powering a lunar rover. Power system components are described and their masses, dimensions, operating powers, and temperatures, are estimated using known or feasible component capabilities. The critical technologies involved are discussed and other potential missions are mentioned.
Williams, M. D.↗
Monolithic Arrays of Grating-Surface-Emitting Diode Lasers and Quantum Well Modulators for Optical Communications
The electro-optic switching properties of injection-coupled coherent 2-D grating-surface-emitting laser arrays with multiple gain sections and quantum well active layers are discussed and demonstrated. Within such an array of injection-coupled grating-surface-emitting lasers, a single gain section can be operated as intra-cavity saturable loss element that can modulate the output of the entire array. Experimental results demonstrate efficient sub-nanosecond switching of high power grading-surface-emitting laser arrays by using only one gain section as an intra-cavity loss modulator.
Carlson, N. W.↗
Active nitrogen partitioning and the nighttime formation of N2O5 in the stratosphere - Simultaneous in situ measurements of NO, NO2, HNO3, O3, and N2O using the BLISS diode laser spectrometer
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Webster, Christopher R.↗
SUNLITE program. Sub-Hertz relative frequency stabilization of two diode laser pumped Nd:YAG lasers locked to a Fabry-Perot interferometer
Two laser pumped Nd:YAG lasers were frequency stabilized to a commercial 6.327 GHz free spectral range Fabry-Perot interferometer yielding a best case beatnote linewidth of 330 MHz. In addition, a Fabry-Perot interferometer with a free spectral range of 680 MHz, a linewidth of 25 kHz, and a finesse of 27,500 was built, and when it was substituted in place of the commercial interferometer, it produced a robust and easily repeatable beatnote linewidth of 700 MHz.
Byer, R. L.↗
In situ stratospheric measurements of CH4, (C-13)H4, N2O, and OC(O-18) using the BLISS tunable diode laser spectrometer
Simultaneous in situ measurements of stratospheric CH4, (C-13)H4, N2O, OC(O-18), pressure, and temperature have been made from Palestine, Texas (32 deg N) in September 1988 with the JPL Balloon-borne Laser In Situ Sensor. Measurements of CH4 and N2O in the altitude range 30-35 km agree well with other measurements, except for an anomalously high value for the N2O at 31 km. Measurements of CH4 support earlier observations of fold in the vertical profile. A ratio for stratospheric (C-13)H4/CH4 of 0.0105 +/- 0.0010 implies an enrichment of delta(C-13) = -45 +/- 92 parts per thousand over the PDB value, in agreement with previous measurements in the troposphere. A large mixing ratio of 1.9 +/- 0.2 ppmv for OC(O-18) is measured, corresponding to an enrichment of delta(O-18) = 280 +/- 50 parts per thousand for the (O-18) isotopic species over the SMOW value.
Webster, Christopher R.↗
Tunable diode laser measurements on the 951.7393/cm line of (C-12)2H4 at planetary atmospheric temperatures
The absolute intensity and the collision broadened half-widths of the 951.7393/cm line, which belongs to the nu7-fundamental band (C-12)2H4, at 152, 202, 252, and 294 K are presented using He, H2, and N2 as broadeners. The temperature dependence of the half-width is determined for line broadening by the planetary atmospheric gases He, H2, and N2.
Brannon, J. F., Jr.↗
Laser diode ignition activities at Sandia National Laboratories
The topics are presented in viewgraph form and include the following: ignition subsystems, enhanced safety, optical ordnance power densities, optical ignition factors, low energy optical ordnance program, absorptance of 2-(5-cyanotetrazolato) pentaaminecobalt(III) perchlorate (CP) near 800 nm, power dependence of doped CP, system operational electrical requirements, dopant concentration effects for different CP particle sizes, ZR/KCLO4 optical ignition thresholds, and electrostatic discharge testing.
Merson, John A.↗
In(X)Ga(1-X) As Strain-Layer Multiple-Quantum-Well Laser Diodes
Fabricated on InP substrates, devices operate at room temperature, emitting at wavelengths near 1.8 micrometers. By suitable modification of structure of devices, possible to achieve operation at any wavelength from 1.6 to 2.5 micrometers: this range important in lidar and in remote sensing of atmospheric gases. Quantum-well and barrier layers sandwiched between two 60-nm-thick layers of lattice-matched InGaAs. InGaAs layers sandwiched between two 150-nm-thick layers of InGaAsP. Those layers sandwiched, in turn, between InP substrate and InP cladding layer. Also layer of InGaAs atop InP cladding layers.
Forouhar, Siamak↗
HO2 detection by near infrared absorption using tunable diode lasers
The strongest absorption lines are in the v sub 2 vibrational band around 1400/cm; several near-coincident line pairs in this region provide max linestrengths of 1.2 x 10 exp -20 sq. cm/(molecule*cm). High Frequency wavelength modulation coupled with sweep integration were used to minimize noise and maintain spectral discrimination. Reduced pressure sampling was performed using supersonic nozzle and an aerodynamic flow cell to minimize residence time and wall losses of radicals. The astigmatic mirror design provides pathlengths up to 200 m in volume of 3 liters with minimal optical interference fringes; longer pathlengths are possible. The detection limit depends on pathlength and minimum fractional absorptions.
Nelson, David↗
Line-center/side-line diode laser seeding for DIAL measurements of the atmosphere
The ability of DIAL systems to probe deeply into the atmosphere is enhanced if the pulsed laser is capable of sequentially operating at different wavelengths, each wavelength corresponding to a different absorption cross-section of the gas of interest. Such wavelength versatility is particularly important for airborne or spaceborne DIAL measurements of H2O(v) due to its strong vertical gradient (several orders of magnitude). Strong H2O(v) cross-sections are necessary to retrieve H2O(v) data from high altitudes while the use of weaker cross sections enables penetration of the DIAL laser pulses to lower altitudes.
Sachse, Glen↗