Fabry-Perot Resonators Built With YBa2Cu3O7−δ Films on Si Substrates

2000 ◽  
Vol 122 (4) ◽  
pp. 785-791 ◽  
Author(s):  
A. R. Kumar ◽  
V. A. Boychev ◽  
Z. M. Zhang ◽  
D. B. Tanner
Keyword(s):  
Film Thickness ◽  
Michelson Interferometer ◽  
Far Infrared ◽  
Partial Coherence ◽  
Optimization Analysis ◽  
Si Substrates ◽  
Future Design ◽  
Fabry Perot ◽  
Htsc Thin Films ◽  
Good Agreement

Fabry-Perot resonators were built from two superconductive YBa2Cu3O7−δ (YBCO) films separated by a spacer. Each film of 35-nm thickness was deposited on a Si substrate, about 204 μm thick. A slow-scan Michelson interferometer was employed to measure the transmittance of the resonator in the far-infrared frequency region from 10 to 90 cm−1 at temperatures between 10 and 300 K. Measurements showed that in the normal state the peak (or resonant) transmittance decreases as temperature is lowered, whereas in the superconducting state it can increase with decreasing temperature. The transmittance of the resonator was calculated using properties of individual reflectors obtained previously. When the effect of partial coherence is taken into consideration, the calculated transmittance is in good agreement with the experiments. Furthermore, the maximum possible resonant transmittance was predicted based on an optimization analysis in which the cavity length is varied. The effect of the YBCO film thickness on the transmittance peaks was also studied, showing that the resonant transmittance decreases but the finesse increases as the film thickness is increased. This study should help improve the future design of Fabry-Perot resonators based on HTSC thin films. [S0022-1481(00)00604-6]

Fabry-Perot Resonators Built With YBa2Cu3O7-δ Films on Si Substrates

1999 ◽  
Author(s):  
A. Ravi Kumar ◽  
Vladimir A. Boychev ◽  
Zhuomin M. Zhang ◽  
David B. Tanner
Keyword(s):  
Film Thickness ◽  
Michelson Interferometer ◽  
Far Infrared ◽  
Partial Coherence ◽  
Optimization Analysis ◽  
Si Substrates ◽  
Future Design ◽  
Fabry Perot ◽  
Htsc Thin Films ◽  
Good Agreement

Abstract Fabry-Perot (F-P) resonators were built from two superconductive YBa2Cu3O7-δ (YBCO) films separated by a spacer. Each film of 35 nm thickness was deposited on a Si substrate ≈0.2 mm thick. A slow-scan Michelson interferometer was employed to measure the transmittance of the resonator in the far-infrared frequency region from 10 to 90 cm−1 at temperatures between 10 and 300 K. Measurements showed that in the normal state the peak (or resonant) transmittance decreases with temperature, whereas in the superconducting state it can increase with decreasing temperature. The transmittance of the resonator was calculated using properties of individual reflectors obtained previously. When the effect of partial coherence is taken into consideration, the calculated transmittance is in good agreement with the experiments. Furthermore, the maximum possible resonant transmittance was predicted based on an optimization analysis considering the interference effects. The effect of the YBCO film thickness on the transmittance peaks was also studied, showing that the resonant transmittance decreases but the finesse increases as the film thickness is increased. This study should help improve the future design of F-P resonators based on HTSC thin films.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

In Situ Diagnostics of Vuv Laser Cvd of Semiconductor Interfaces by Ftir Spectroscopy and Spectroscopic Ellipsometry

1995 ◽  
Vol 397 ◽  
Author(s):  
M. Barth ◽  
J. Knobloch ◽  
P. Hess
Keyword(s):  
Film Thickness ◽  
Bulk Material ◽  
Substrate Surface ◽  
Cluster Formation ◽  
Interface Layer ◽  
Native Oxide ◽  
Initial Growth ◽  
Difference Spectra ◽  
Si Substrates

ABSTRACTThe growth of high quality amorphous hydrogenated semiconductor films was explored with different in situ spectroscopic methods. Nucleation of ArF laser-induced CVD of a-Ge:H on different substrates was investigated by real time ellipsometry, whereas the F2 laser (157nm) deposition of a-Si:H was monitored by FTIR transmission spectroscopy. The ellipsometric studies reveal a significant influence of the substrate surface on the nucleation stage, which in fact determines the electronic and mechanical properties of the bulk material. Coalescence of initial clusters occurs at a thickness of 16 Å for atomically smooth hydrogen-terminated c-Si substrates, whereas on native oxide covered c-Si substrates the bulk volume void fractions are not reached until 35 Å film thickness. For the first time we present a series of IR transmission spectra with monolayer resolution of the initial growth of a-Si:H. Hereby the film thickness was measured simultaneously using a quartz crystal microbalance with corresponding sensitivity. The results give evidence for cluster formation with a coalescence radius of about 20 Å. Difference spectra calculated for layers at different depths with definite thickness reveal that the hydrogen-rich interface layer stays at the substrate surface and does not move with the surface of the growing film. The decrease of the Urbach energy switching from native oxide to H-terminated substrates suggests a strong influence of the interface morphology on the bulk material quality.

Isotope shift and hyperfine structure in the atomic spectrum of tin

1973 ◽  
Vol 332 (1588) ◽  
pp. 129-138 ◽  
Keyword(s):  
Stable Isotopes ◽  
Hyperfine Structure ◽  
Nuclear Charge ◽  
Light Sources ◽  
Atomic Spectrum ◽  
Nuclear Charge Distribution ◽  
Fabry Perot ◽  
Self Consistent ◽  
Structure Constants ◽  
Good Agreement

Three lines in the atomic spectrum of tin, λ 3262 Å, λ 3283 Å and λ 6454Å have been studied in emission under high resolution with the use of light sources containing enriched isotopic samples. Results are reported for isotope shifts in these lines for the abundant stable isotopes ( A ≽ 116). Pressure-scanned Fabry–Perot etalons provided the necessary resolution; the spectrograms for λ 6454 Å were recorded and analysed by digital techniques, and for this line hyperfine structure constants required in the interpretation of the data were also evaluated. The results for the three lines are not in good agreement with earlier work, but are shown to be self-consistent by means of a King plot. Their interpretation in terms of the nuclear charge distribution is considered in the following paper.

Optimized design of far-infrared Fabry-Perot resonators fabricated from YBa/sub 2/Cu/sub 3/O/sub 7/

1993 ◽  
Vol 3 (1) ◽  
pp. 2852-2855 ◽  
Author(s):  
C.G. Malone ◽  
Z.M. Zhang ◽  
M.I. Flik ◽  
E.G. Cravalho
Keyword(s):  
Far Infrared ◽  
Optimized Design ◽  
Fabry Perot

Event-Locked Time-Resolved Fourier Spectroscopy

1997 ◽  
Vol 51 (8) ◽  
pp. 1106-1112 ◽  
Author(s):  
H. Weidner ◽  
R. E. Peale
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Michelson Interferometer ◽  
Far Infrared ◽  
Time Base ◽  
The Novel ◽  
Time Resolved ◽  
Mathematical Algorithm ◽  
Scan Time ◽  
Recorded Data

A low-cost method of adding time-resolving capability to commercial Fourier transform spectrometers with a continuously scanning Michelson interferometer has been developed. This method is specifically designed to eliminate noise and artifacts caused by mirror-speed variations in the interferometer. The method exists of two parts: (1) a novel timing scheme for synchronizing the transient events under study and the digitizing of the interferogram and (2) a mathematical algorithm for extracting the spectral information from the recorded data. The novel timing scheme is a modification of the well-known interleaved, or stroboscopic, method. It achieves the same timing accuracy, signal-to-noise ratio, and freedom from artifacts as step-scan time-resolving Fourier spectrometers by locking the sampling of the interferogram to a stable time base rather than to the occurrences of the HeNe fringes. The necessary pathlength-difference information at which samples are taken is obtained from a record of the mirror speed. The resulting interferograms with uneven pathlength-difference spacings are transformed into wavenumber space by least-squares fits of periodic functions. Spectra from the far-infrared to the upper visible at resolutions up to 0.2 cm−1 are used to demonstrate the utility of this method.

scholarly journals Analysis of light noise sources in a recycled Michelson interferometer with Fabry–Perot arms

2000 ◽  
Vol 17 (1) ◽  
pp. 120 ◽  
Author(s):  
J. B. Camp ◽  
H. Yamamoto ◽  
S. E. Whitcomb ◽  
D. E. McClelland
Keyword(s):  
Michelson Interferometer ◽  
Noise Sources ◽  
Fabry Perot

Morphology of Voltage-Triggered Ordered Wrinkles of a Dielectric Elastomer Sheet

2017 ◽  
Vol 84 (11) ◽  
Author(s):  
Guoyong Mao ◽  
Lei Wu ◽  
Xueya Liang ◽  
Shaoxing Qu
Keyword(s):  
High Voltage ◽  
Optical Sensor ◽  
Material Science ◽  
Dielectric Elastomer ◽  
Theoretical Studies ◽  
Science And Engineering ◽  
Future Design ◽  
Experimental And Theoretical Studies ◽  
Theory And Experiment ◽  
Good Agreement

Wrinkles widely existing in sheets and membranes have attracted a lot of attention in the fields of material science and engineering applications. In this paper, we present a new method to generate ordered (striplike) and steady wrinkles of a constrained dielectric elastomer (DE) sheet coated with soft electrodes on both sides subjected to high voltage. When the voltage reaches a certain value, wrinkles will nucleate and grow. We conduct both experimental and theoretical studies to investigate the wavelength and amplitude of the wrinkle. The results show a good agreement between theory and experiment. Moreover, the amplitude and wavelength of ordered wrinkles can be tuned by varying the prestretch and geometry of the DE sheet, as well as the applying voltage. This study can help future design of DE transducers such as diffraction grating and optical sensor.

Liquid-helium-cooled Fabry-Perot spectrometer and the frequency switching method for far-infrared spectroscopic observations

1990 ◽  
Author(s):  
Takao Nakagawa ◽  
Haruyuki Okuda ◽  
Hiroshi Shibai ◽  
Hideo Matsuhara ◽  
Yukiyasu Kobayashi ◽  
...  
Keyword(s):  
Liquid Helium ◽  
Far Infrared ◽  
Spectroscopic Observations ◽  
Fabry Perot ◽  
Infrared Spectroscopic ◽  
Switching Method

Some Limitations in Applying Classical EHD Film Thickness Formulas to a High-Speed Bearing

1981 ◽  
Vol 103 (2) ◽  
pp. 295-301 ◽  
Author(s):  
J. J. Coy ◽  
E. V. Zaretsky
Keyword(s):  
Film Thickness ◽  
High Speed ◽  
Heating Effects ◽  
Theoretical Predictions ◽  
Traction Fluid ◽  
Shear Heating ◽  
Thickness Measurements ◽  
Inner Race ◽  
Maximum Stresses ◽  
Good Agreement

Elastohydrodynamic film thickness was measured for a 20-mm ball bearing using the capacitance technique. The bearing was thrust loaded to 90, 448, and 778 N (20, 100, and 175 lb). The corresponding maximum stresses on the inner race were 1.28, 2.09, and 2.45 GPa (185,000, 303,000, and 356,000 psi). Test speeds ranged from 400 to 14,000 rpm. Film thickness measurements were taken with four different lubricants: (a) synthetic paraffinic, (b) synthetic paraffinic with additives, (c) neopentylpolyol (tetra) ester meeting MIL-L-23699A specifications, and (d) synthetic cycloaliphatic hydrocarbon traction fluid. The test bearing was mist lubricated. Test temperatures were 300, 338, and 393 K. The measured results were compared to theoretical predictions using the formulae of Grubin, Archard and Cowking, Dowson and Higginson, and Hamrock and Dowson. There was good agreement with theory at low dimensionless speed, but the film was much smaller than theory predicts at higher speeds. This was due to kinematic starvation and inlet shear heating effects. Comparisons with Chiu’s theory on starvation and Cheng’s theory on inlet shear heating were made.

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