Physical Sciences

V-Assembly Dual-Head Efficiency Resonator (VADER) Laser Transmitter

The combined features form a unit with new performance levels. A complete demonstration breadboard unit for advanced development as a high-TRL (technology readiness level) system has been constructed and characterized. Infusion of several new component technologies, such as ceramic:YAG material and high-power laser diode arrays (LDAs), combined with a proprietary minimal part count architecture, has resulted in dramatic performance gains. The proprietary dual-head configuration employs a pair of side-pumped laser slabs, optically in series in the cavity, but at opposing polarization orientations. This promises tremendous power range scalability, simplified and symmetrical thermal lens control, unprecedented stored energy extraction efficiency, and inherent diffraction limited TEM00 beam quality.

Posted in: Tech Briefs, Physical Sciences, Photonics, Briefs, TSP

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Twin Head Efficient Oscillator Development for the ACE Multi- Beam Lidar and 3D-Winds

This technology is applicable to atmospheric lidar, Doppler wind measurements, interplanetary laser communications, and materials processing. The Twin Head Efficient Oscillator (THEO) concept uses a pair of smaller, identical laser pump modules, oriented to remove asymmetrical thermo-optical effects typical in single-slab lasers such as HOMER (High Output Maximum Efficiency Resonator), MLA (Mercury Laser Altimeter), LOLA Lunar Orbiter Laser Altimeter, and GLAS (Geoscience Laser Altimeter), while simultaneously increasing efficiency and lifetime. This creates 100+ mJ pulses in an oscillator-only design, with reduced risk of optical damage, record efficiency, high stability, long life, and high TEM00 beam quality typical of much smaller rod-based cavities. Near-field-beam quality is critical to efficient second harmonic generation (SHG 532 nm), which is typically poor in slab-based Nd:YAG lasers.

Posted in: Physical Sciences, Photonics, Briefs, TSP

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Planetary Polarization Nephelometer

Instrument provides more detailed information on aerosols encountered in a planetary environment. Aerosols in planetary atmospheres have a significant impact on the energy balance of the planets, yet are often poorly characterized. An in situ instrument was developed that would provide more diagnostic information on the nature of aerosols it encountered if deployed on a planetary descent probe. Previous probe instruments only measured intensity phase functions, but much particle ambiguity remains with only this information. Adding the polarization phase function greatly reduces particle characteristic ambiguities, but also adds more challenges in designing a measurement approach. Laboratory instrumentation to measure intensity and polarization phase functions have existed since the early 1970s, but these instruments employed quarter-wave plates and Pockels cells to modulate the illuminating beam and the scattered light to isolate the intensity and polarization phase functions. Both of these components are unstable except under tightly controlled thermal conditions. This solution avoids the use of thermally sensitive components such as quarter- wave plates or Pockels cells, and avoids requiring the detectors to be placed around the sensing volume.

Posted in: Physical Sciences, Photonics, Briefs, TSP

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Optical Tunable-Based Transmitter for Multiple High-Frequency Bands

Applications include satellite communications, optical communications networks, and RF antenna applications. The purpose of this innovation is to be able to deliver, individually or simultaneously, multiple microwave high-frequency bands including, but not limited to, L (1.5 GHz), C (7 GHz), X (8.4 GHz), Ku (14.5 GHz), Ka (32 GHz), and Q (38 GHz) frequencies at high data rates and with minimal hardware, particularly for use in satellite-to-satellite communications applications. Additionally, this innovation would be a satellite-based transmitter with a significant reduction in weight, mass, and power when compared to current, conventional technologies.

Posted in: Physical Sciences, Photonics, Briefs

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Scatter-Reducing Sounding Filtration Using a Genetic Algorithm and Mean Monthly Standard Deviation

Retrieval algorithms like that used by the Orbiting Carbon Observatory (OCO)-2 mission generate massive quantities of data of varying quality and reliability. A computationally efficient, simple method of labeling problematic datapoints or predicting soundings that will fail is required for basic operation, given that only 6% of the retrieved data may be operationally processed. This method automatically obtains a filter designed to reduce scatter based on a small number of input features.

Posted in: Physical Sciences, Software, Briefs, TSP

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GPS Estimates of Integrated Precipitable Water Aid Weather Forecasters

This technique improves weather-forecasting operations. Global Positioning System (GPS) meteorology provides enhanced density, low-latency (30-min resolution), integrated precipitable water (IPW) estimates to NOAA NWS (National Oceanic and Atmospheric Administration National Weather Service) Weather Forecast Offices (WFOs) to provide improved model and satellite data verification capability and more accurate forecasts of extreme weather such as flooding. An early activity of this project was to increase the number of stations contributing to the NOAA Earth System Research Laboratory (ESRL) GPS meteorology observing network in Southern California by about 27 stations. Following this, the Los Angeles/Oxnard and San Diego WFOs began using the enhanced GPS-based IPW measurements provided by ESRL in the 2012 and 2013 monsoon seasons. Forecasters found GPS IPW to be an effective tool in evaluating model performance, and in monitoring monsoon development between weather model runs for improved flood forecasting.

Posted in: Physical Sciences, Data Acquisition, Briefs, TSP

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High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges.

Posted in: Physical Sciences, Data Acquisition, Briefs

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