NASA Scientific and Technical Aerospace Reports - The University ...

y etching part of the thermal SiO2 beneath the tubes and minimizing heat conduction through the substrate, pressure
sensitivity was extended toward lower pressures. Results are compared to a conventional thin film meander resistor, which was
fabricated and whose pressure response was also measured for comparative purposes.
Derived from text
Carbon Nanotubes; Dynamic Range; Microelectromechanical Systems; Pressure Sensors; Vacuum Gages; Equipment
Specifications
36
LASERS AND MASERS
Includes lasing theory, laser pumping techniques, maser amplifiers, laser materials, and the assessment of laser and maser outputs.
For cases where the application of the laser or maser is emphasized see also the specific category where the application is treated. For
related information see also 76 Solid-State Physics.
20100017264 Massachusetts Inst. of Tech., Cambridge, MA, USA
Tuning a Tetrahertz Wire Laser
Qin, Qi; Williams, Benjamin S.; Kumar, Sushil; Reno, John L.; Hu, Qing; Nature Photonics; December 2009; Volume 3,
pp. 732-737; In English; Original contains color illustrations
Contract(s)/Grant(s): DE-AC04-94AL85000; NNX07AI99G; Copyright; Avail.: Other Sources
ONLINE: http://dx.doi.org/10.1038/NPHOTON.2009.218
Tunable terahertz lasers are desirable in applications in sensing and spectroscopy because many biochemical species have
strong spectral fingerprints at terahertz frequencies. Conventionally, the frequency of a laser is tuned in a similar manner to
a stringed musical instrument, in which pitch is varied by changing the length of the string (the longitudinal component of the
wave vector) and/ or its tension (the refractive index). However, such methods are difficult to implement in terahertz
semiconductor lasers because of their poor outcoupling efficiencies. Here, we demonstrate a novel tuning mechanism based
on a unique ‘wire laser’ device for which the transverse dimension w is much much less than lambda. Placing a movable object
close to the wire laser manipulates a large fraction of the waveguided mode propagating outside the cavity, thereby tuning its
resonant frequency. Continuous single-mode redshift and blueshift tuning is demonstrated for the same device by using either
a dielectric or metallic movable object. In combination, this enables a frequency tuning of approximately equal to 137 GHz
(3.6%) from a single laser device at approximately equal to 3.8 THz.
Author
Biochemistry; Spectroscopy; Tunable Lasers; Wire; Electrical Engineering
20100017666 Aerospace Testing Alliance, Arnold AFB, TN USA; Arnold Engineering Development Center, USA
Pulsed Electron Beam Spectroscopy for Temperature Measurements in Hypersonic Flows
Nelius, Andy; Wehrmeyer, Joe; January 2010; 47 pp.; In English; Original contains color illustrations
Contract(s)/Grant(s): Proj-11172
Report No.(s): AD-A516962; AEDC-TR-09-T-5; No Copyright; Avail.: Defense Technical Information Center (DTIC)
ONLINE: http://hdl.handle.net/100.2/ADA516962
Reports development of pulsed electron beam system for nonintrusive temperature measurements of hypersonic flows.
DTIC
Electron Beams; Hypersonic Flow; Pulsed Lasers; Spectroscopy; Temperature Measurement
37
MECHANICAL ENGINEERING
Includes mechanical devices and equipment; machine elements and processes. For cases where the application of a device or the host
vehicle is emphasized see also the specific category where the application or vehicle is treated. For robotics see 63 Cybernetics,
Artificial Intelligence, and Robotics; and 54 Man/System Technology and Life Support.
20100017389 Royal Inst. of Tech., Stockholm, Sweden
Mechanical Model of an Axial Piston Machine
Grip, Rasmus L.; January 2009; 136 pp.; In English
Report No.(s): PB2010-106014; TRITA-MMK-2009:16; Copyright; Avail.: National Technical Information Service (NTIS)
A mechanical model of an axial piston-type machine with a so-called wobble plate and Z-shaft mechanism is presented.
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