Optimization of the intra-cavity optical flux in the unstable direction in RF excited annular CO2laser in terms of power stability

2013 ◽  
Author(s):  
Viktor Granson ◽  
Francisco J. Villarreal ◽  
Jochen Deile ◽  
Jesus F. Monjardin ◽  
Shadi Sumrain
Keyword(s):  
Power Stability ◽  
Optical Flux ◽  
Unstable Direction

A New Flexible Rapid Thermal Processing System

1995 ◽  
Vol 389 ◽  
Author(s):  
K. C. Saraswat ◽  
Y. Chen ◽  
L. Degertekin ◽  
B. T. Khuri-Yakub
Keyword(s):  
Control System ◽  
Real Time ◽  
Processing System ◽  
Process Conditions ◽  
Temperature Uniformity ◽  
Real Time Control ◽  
Wafer Temperature ◽  
Time Control ◽  
Wide Range ◽  
Optical Flux

ABSTRACTA highly flexible Rapid Thermal Multiprocessing (RTM) reactor is described. This flexibility is the result of several new innovations: a lamp system, an acoustic thermometer and a real-time control system. The new lamp has been optimally designed through the use of a “virtual reactor” methodology to obtain the best possible wafer temperature uniformity. It consists of multiple concentric rings composed of light bulbs with horizontal filaments. Each ring is independently and dynamically controlled providing better control over the spatial and temporal optical flux profile resulting in excellent temperature uniformity over a wide range of process conditions. An acoustic thermometer non-invasively allows complete wafer temperature tomography under all process conditions - a critically important measurement never obtained before. For real-time equipment and process control a model based multivariable control system has been developed. Extensive integration of computers and related technology for specification, communication, execution, monitoring, control, and diagnosis demonstrates the programmability of the RTM.

scholarly journals Equilibrium measures for the Hénon map at the first bifurcation: uniqueness and geometric/statistical properties

2014 ◽  
Vol 36 (1) ◽  
pp. 215-255 ◽  
Author(s):  
SAMUEL SENTI ◽  
HIROKI TAKAHASI
Keyword(s):  
Existence And Uniqueness ◽  
Thermodynamic Formalism ◽  
Invariant Probability Measure ◽  
Statistical Properties ◽  
Limit Set ◽  
Bifurcation Parameter ◽  
Large Interval ◽  
Equilibrium Measures ◽  
Uniform Hyperbolicity ◽  
Unstable Direction

For strongly dissipative Hénon maps at the first bifurcation parameter where the uniform hyperbolicity is destroyed by the formation of tangencies inside the limit set, we establish a thermodynamic formalism, i.e. we prove the existence and uniqueness of an invariant probability measure that minimizes the free energy associated with a non-continuous geometric potential$-t\log J^{u}$, where$t\in \mathbb{R}$is in a certain large interval and$J^{u}$denotes the Jacobian in the unstable direction. We obtain geometric and statistical properties of these measures.

Improving laser power stability with a photosensitive lens

2021 ◽  
Vol 92 (8) ◽  
pp. 083003
Author(s):  
Xiaolei Guan ◽  
Tongyun Zhang ◽  
Haosen Shang ◽  
Duo Pan ◽  
Jin He ◽  
...  
Keyword(s):  
Laser Power ◽  
Power Stability

Digital control system for higher laser power stability

2016 ◽  
Vol 45 (4) ◽  
pp. 0406004 ◽  
Author(s):  
李营营 Li Yingying ◽  
江志坤 Jiang Zhikun ◽  
王安琪 Wang Anqi
Keyword(s):  
Control System ◽  
Digital Control ◽  
Laser Power ◽  
Digital Control System ◽  
Power Stability

scholarly journals Predictable quantum efficient detector for low optical flux measurements

2020 ◽  
Vol 27 (2) ◽  
pp. 190-194
Author(s):  
Santeri Porrasmaa ◽  
Timo Dönsberg ◽  
Farshid Manoocheri ◽  
Erkki Ikonen
Keyword(s):  
Flux Measurements ◽  
Optical Flux

scholarly journals Regulation of accretion by its outflow in a symbiotic star: the 2016 outflow fast state of MWC 560

2020 ◽  
Vol 492 (3) ◽  
pp. 3107-3127 ◽  
Author(s):  
Adrian B Lucy ◽  
J L Sokoloski ◽  
U Munari ◽  
Nirupam Roy ◽  
N Paul M Kuin ◽  
...  
Keyword(s):  
Symbiotic Star ◽  
Fast State ◽  
Low Velocity ◽  
X Ray ◽  
Broad Absorption Line ◽  
Multi Wavelength ◽  
Order Of Magnitude ◽  
The Stability ◽  
Ultraviolet Observations ◽  
Optical Flux

ABSTRACT How are accretion discs affected by their outflows? To address this question for white dwarfs accreting from cool giants, we performed optical, radio, X-ray, and ultraviolet observations of the outflow-driving symbiotic star MWC 560 (≡V694 Mon) during its 2016 optical high state. We tracked multi-wavelength changes that signalled an abrupt increase in outflow power at the initiation of a months-long outflow fast state, just as the optical flux peaked: (1) an abrupt doubling of Balmer absorption velocities; (2) the onset of a 20 μJy per month increase in radio flux; and (3) an order-of-magnitude increase in soft X-ray flux. Juxtaposing to prior X-ray observations and their coeval optical spectra, we infer that both high-velocity and low-velocity optical outflow components must be simultaneously present to yield a large soft X-ray flux, which may originate in shocks where these fast and slow absorbers collide. Our optical and ultraviolet spectra indicate that the broad absorption-line gas was fast, stable, and dense (≳106.5  cm−3) throughout the 2016 outflow fast state, steadily feeding a lower density (≲105.5 cm−3) region of radio-emitting gas. Persistent optical and ultraviolet flickering indicate that the accretion disc remained intact. The stability of these properties in 2016 contrasts to their instability during MWC 560’s 1990 outburst, even though the disc reached a similar accretion rate. We propose that the self-regulatory effect of a steady fast outflow from the disc in 2016 prevented a catastrophic ejection of the inner disc. This behaviour in a symbiotic binary resembles disc/outflow relationships governing accretion state changes in X-ray binaries.

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