Wave‐number stability of a laser diode mounted in a closed cycle helium refrigerator

1979 ◽  
Vol 50 (12) ◽  
pp. 1622-1625 ◽  
Author(s):  
G. N. Steinberg
Keyword(s):  
Laser Diode ◽  
Wave Number ◽  
Closed Cycle ◽  
Helium Refrigerator

Use of a Closed Cycle Helium Refrigerator for Mössbauer Studies

1968 ◽  
Vol 39 (7) ◽  
pp. 995-997 ◽  
Author(s):  
J. W. Wiggins ◽  
J. R. Oleson ◽  
Y. K. Lee ◽  
J. C. Walker
Keyword(s):  
Closed Cycle ◽  
Mössbauer Studies ◽  
Helium Refrigerator

Measurement of the cooling capacity of an RMC‐Cryosystems Model LTS 4.5‐025 closed‐cycle helium refrigerator

1991 ◽  
Vol 62 (5) ◽  
pp. 1309-1310 ◽  
Author(s):  
R. L. de Zafra ◽  
W. H. Mallison ◽  
L. K. Emmons ◽  
D. Koller
Keyword(s):  
Cooling Capacity ◽  
Closed Cycle ◽  
Helium Refrigerator

scholarly journals Reducing the background of ultra-low-temperature X-ray diffraction data through new methods and advanced materials

2019 ◽  
Vol 52 (2) ◽  
pp. 445-450 ◽  
Author(s):  
Charles James McMonagle ◽  
Michael Richard Probert
Keyword(s):  
Diffraction Data ◽  
Advanced Materials ◽  
Average Intensity ◽  
Closed Cycle ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Methods ◽  
Fold Reduction ◽  
Scattering Contribution ◽  
Helium Refrigerator

New methods and advanced materials that significantly reduce the background when collecting single-crystal X-ray diffraction data at ultra-low temperatures using a closed-cycle helium refrigerator are presented here. These include a magnetically controlled internal beamstop and a separate internal collimator that together completely remove the scattering contribution to the background from the beryllium vacuum chamber. Additionally, a new radiation shield made from flexible graphite significantly reduces the background and maintains excellent thermal properties. In combination these improvements have led to a sixfold reduction in the average intensity and a 15-fold reduction in peak intensity of the background observed for diffraction experiments conducted with a closed-cycle helium refrigerator. Moreover, access to ultra-low base temperatures, 2.05 K, has been maintained. The design and implementation of these methods are discussed along with a case study of vitamin C to demonstrate the effectiveness of the improvements.

High Efficiency Crystallization of Silicon Thin Films Using Continuous Wave Infrared Laser

2006 ◽  
Vol 910 ◽  
Author(s):  
Naoki Sano ◽  
Masato Maki ◽  
Nobuyuki Andoh ◽  
Toshiyuki Sameshima
Keyword(s):  
Thin Films ◽  
Laser Diode ◽  
Near Infrared ◽  
High Efficiency ◽  
Continuous Wave ◽  
Infrared Laser ◽  
Silicon Films ◽  
Optical Absorption Coefficient ◽  
Wave Number ◽  
Silicon Thin Films

AbstractLaser crystallization of silicon thin films on inexpensive glass substrates with a photo-absorption layer of diamond like-carbon (DLC) film was investigated. Scanned near-infrared beam emitted from a continuous wave (CW) laser diode at speed of 30 cm/s with power density of 30 kW/cm2 and wavelength of 940nm was effectively absorbed by DLC films, and changed to thermal energy for heating underlying silicon films with thickness of 50 nm. As a result, crystallization of silicon films was achieved. Raman scattering spectra was measure for the structural analysis of silicon films, and the sharp TO phonon peak at wave number of 520 cm-1 was observed. It shows that silicon films were effectively crystallized using the near-infrared laser diode. On the other hand, no crystallization was observed when the laser diode was directly irradiated to 50-nm-Si/quartz, because silicon has no optical absorption coefficient at 940 nm.

Sign in / Sign up

Export Citation Format

Share Document