Thermo-optical measurements of ytterbium doped ceramics (Sc2O3, Y203, Lu203, YAG) and crystals (YAG, CaF2) at cryogenic temperatures

2013 ◽  
Author(s):  
B. Le Garrec ◽  
V. Cardinali ◽  
G. Bourdet
Keyword(s):  
Optical Measurements ◽  
Cryogenic Temperatures

scholarly journals Magnetoconductivity and Terahertz Response of a HgCdTe Epitaxial Layer

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4341 ◽  
Author(s):  
Dmitriy Yavorskiy ◽  
Krzysztof Karpierz ◽  
Michał Baj ◽  
Małgorzata Bąk ◽  
Nikolai Mikhailov ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Optical Measurements ◽  
Cryogenic Temperatures ◽  
Resonant Response ◽  
Mobility Spectrum ◽  
Resonant Line ◽  
Circular Polarizer ◽  
Photon Frequency ◽  
Thz Detector ◽  
The One

An epitaxial layer of HgCdTe—a THz detector—was studied in magnetotransmission, magnetoconductivity and magnetophotoconductivity experiments at cryogenic temperatures. In the optical measurements, monochromatic excitation with photon frequency ranging from 0.05 THz to 2.5 THz was used. We show a resonant response of the detector at magnetic fields as small as 10 mT with the width of the resonant line equal to about 5 mT. Application of a circular polarizer at 2.5 THz measurements allowed for confirming selection rules predicted by the theory of optical transitions in a narrow-gap semiconductor and to estimate the band-gap to be equal to about 4.5 meV. The magnetoconductivity tensor was determined as a function of magnetic field and temperature 2 K < T < 120 K and analysed with a standard one-carrier conductivity model and the mobility spectrum technique. The sample showed n-type conductivity at all temperatures. At temperatures above about 30 K, conductivity was found to be reasonably described by the one-carrier model. At lower temperatures, this description is not accurate. The algorithm of the spectrum of mobility applied to data measured below 30 K showed presence of three types of carriers which were tentatively interpreted as electrons, light holes and heavy holes. The mobility of electrons and light holes is of the order of 10 6 cm 2 /Vs at the lowest temperatures. Magnetophotoconductivity experiments allowed for proposing a detector working at 2 K and 50 mT with a flat response between 0.05 THz and 2.5 THz.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

TEM characterization of proton-exchanged LiNbO3 optical waveguides

1986 ◽  
Vol 44 ◽  
pp. 480-481
Author(s):  
W. E. Lee
Keyword(s):  
Refractive Index ◽  
Benzoic Acid ◽  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Index Of Refraction ◽  
Optical Measurements ◽  
Lithium Ions ◽  
Wide Channel ◽  
Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

Magnetic and optical measurements and signatures of reconnection in the cusp and vicinity

2015 ◽  
Vol 185 (6) ◽  
pp. 655-663
Author(s):  
V.V. Safargaleev ◽  
T.I. Sergienko ◽  
A.V. Safargaleev ◽  
A.L. Kotikov
Keyword(s):  
Optical Measurements

Optical measurements for a superorbital expansion tube

1997 ◽  
Author(s):  
Margaret Wegener ◽  
Alexis Bishop ◽  
Amberyn Thomas ◽  
Margaret Wegener ◽  
Alexis Bishop ◽  
...  
Keyword(s):  
Optical Measurements ◽  
Expansion Tube

The Removal of Tunnel Vibration Induced Corruption in Aero-Optical Measurements

2014 ◽  
Author(s):  
Nicholas G. De Lucca ◽  
Stanislav Gordeyev ◽  
Adam E. Smith ◽  
Eric J. Jumper ◽  
Matthew Whiteley ◽  
...  
Keyword(s):  
Optical Measurements

SANDMEYER SSC INVAR 36

Alloy Digest ◽  
2012 ◽  
Vol 61 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Coefficient Of Thermal Expansion ◽  
Iron Alloy ◽  
Gas Production ◽  
Liquefied Natural Gas ◽  
Cryogenic Temperatures ◽  
Steel Company ◽  
Nickel Iron ◽  
Composite Tooling ◽  
Nickel Iron Alloy

Abstract SSC Invar 36 was developed for use in applications where dimensional stability is essential. It is a nickel-iron alloy with a very low coefficient of thermal expansion from cryogenic temperatures to 200 deg C (390 deg F). It is utilized in aerospace composite tooling and die applications, as well as laser components, and cryogenic components and piping: liquefied natural gas production, storage, and transportation. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Fe-158. Producer or source: Sandmeyer Steel Company. Originally published December 2011, revised February 2012.

INCONEL ALLOY X-750

Alloy Digest ◽  
1966 ◽  
Vol 15 (7) ◽  
Keyword(s):  
Gas Turbines ◽  
Rupture Strength ◽  
Low Cost ◽  
High Strength ◽  
Heat Treating ◽  
Chromium Alloy ◽  
Cryogenic Temperatures ◽  
Inconel Alloy ◽  
Nickel Chromium ◽  
Corrosion And Oxidation

Abstract INCONEL alloy X-750 is an age-hardenable, nickel-chromium alloy used for its corrosion and oxidation resistance and high creep rupture strength at temperature up to 1500 F. It also has excellent properties at cryogenic temperatures. It was originally developed for use in gas turbines, but because of its low cost, high strength and weldability it has become the standards choice for a wide variety of applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-115. Producer or source: Huntington Alloy Products Division, An INCO Company.

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