186 MHz Low Amplitude Noise Erbium-Doped-Fiber Femtosecond Laser

2014 ◽  
Vol 41 (8) ◽  
pp. 0802004
Author(s):  
闫露露 Yan Lulu ◽  
张颜艳 Zhang Yanyan ◽  
赵文宇 Zhao Wenyu ◽  
孟森 Meng Sen ◽  
郑恩让 Zheng Enrang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Amplitude Noise ◽  
Erbium Doped ◽  
Low Amplitude

A New Strategy for Detecting Gear Faults Using Denoising With the Orthogonal Discrete Wavelet Transform (ODWT)

1999 ◽  
Author(s):  
Sidi M. Berri ◽  
J. M. Klosner
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Power Transmission ◽  
Discrete Wavelet ◽  
Amplitude Noise ◽  
Transmission Pair ◽  
New Strategy ◽  
Band Pass ◽  
Local Defects ◽  
Low Amplitude

Abstract This paper investigates a new strategy for early detection of defects in a power transmission pair of spur gears. Sensitivity to local defects is enhanced by processing the signal as follows. The orthogonal discrete wavelet transform (ODWT) of the band-pass filtered averaged signal is first obtained. This is followed by thresholding in the wavelet domain, thereby removing the low amplitude noise contribution. The inverse wavelet transform then essentially reconstructs the component of the signal that is due to the defect. Experimental results demonstrate the efficiency of this procedure.

Single-frequency erbium-doped fibre laser with random distributed feedback based on disordered structures produced by femtosecond laser radiation

2021 ◽  
Vol 51 (12) ◽  
pp. 1051-1055
Author(s):  
Mikhail Igorevich Skvortsov ◽  
S R Abdullina ◽  
Alexey Anatolyevich Wolf ◽  
A V Dostovalov ◽  
A E Churin ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Femtosecond Laser ◽  
Distributed Feedback ◽  
Single Frequency ◽  
Fibre Laser ◽  
Femtosecond Laser Radiation ◽  
Disordered Structures ◽  
Erbium Doped

scholarly journals Nonlinearity and noise at the rod—rod bipolar cell synapse

2010 ◽  
Vol 28 (1) ◽  
pp. 61-68 ◽  
Author(s):  
E. BRADY TREXLER ◽  
ALEXANDER R.R. CASTI ◽  
YU ZHANG
Keyword(s):  
Quantum Efficiency ◽  
Single Photon ◽  
Signal To Noise Ratio ◽  
Discrete Events ◽  
Amplitude Noise ◽  
Synaptic Noise ◽  
Suction Electrode ◽  
Suppression Mechanism ◽  
Low Amplitude ◽  
Cell Synapse

AbstractIn the retina, rod bipolar (RBP) cells synapse with many rods, and suppression of rod outer segment and synaptic noise is necessary for their detection of rod single-photon responses (SPRs). Depending on the rods’ signal-to-noise ratio (SNR), the suppression mechanism will likely eliminate some SPRs as well, resulting in decreased quantum efficiency. We examined this synapse in rabbit, where 100 rods converge onto each RBP. Suction electrode recordings showed that rabbit rod SPRs were difficult to distinguish from noise (independent SNR estimates were 2.3 and 2.8). Nonlinear transmission from rods to RBPs improved response detection (SNR = 8.7), but a large portion of the rod SPRs was discarded. For the dimmest flashes, the loss approached 90%. Despite the high rejection ratio, noise of two distinct types was apparent in the RBP traces: low-amplitude rumblings and discrete events that resembled the SPR. The SPR-like event frequency suggests that they result from thermal isomerizations of rhodopsin, which occurred at the rate 0.033/s/rod. The presence of low-amplitude noise is explained by a sigmoidal input–output relationship at the rod—RBP synapse and the input of noisy rods. The rabbit rod SNR and RBP quantum efficiency are the lowest yet reported, suggesting that the quantum efficiency of the rod—RBP synapse may depend on the SNR in rods. These results point to the possibility that fewer photoisomerizations are discarded for species such as primate, which has a higher rod SNR.

Femtosecond laser direct writing of gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass

2009 ◽  
Vol 42 (20) ◽  
pp. 205106 ◽  
Author(s):  
K C Vishnubhatla ◽  
S Venugopal Rao ◽  
R Sai Santosh Kumar ◽  
R Osellame ◽  
S N B Bhaktha ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Quantum Efficiency ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
High Quantum Efficiency ◽  
High Quantum ◽  
Erbium Doped

Spectroscopic and upconversion properties of erbium-doped potassium lithium tantalate niobate crystals under 800 nm femtosecond laser excitation

2010 ◽  
Vol 108 (4) ◽  
pp. 043520 ◽  
Author(s):  
Lei Li ◽  
Zhongxiang Zhou ◽  
Hao Tian ◽  
Dewei Gong ◽  
Zhenling Yang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Excitation ◽  
Lithium Tantalate ◽  
Erbium Doped
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