In-line phase-sensitive amplifier with optical-PLL-controlled internal pump light source

1997 ◽  
Vol 33 (25) ◽  
pp. 2155 ◽  
Author(s):  
W. Imajuku ◽  
A. Takada
Keyword(s):  
Light Source ◽  
Pump Light ◽  
Phase Sensitive

Intensities in Raman spectra III. A photoelectric recording Raman spectrometer for intensity measurements

1956 ◽  
Vol 237 (1209) ◽  
pp. 186-196 ◽  
Keyword(s):  
Light Source ◽  
High Intensity ◽  
Room Temperature ◽  
Recording System ◽  
Photoelectric Recording ◽  
Intensity Measurements ◽  
Wide Range ◽  
Recording Potentiometer ◽  
Phase Sensitive ◽  
High Intensity Light

A description is given of a Raman apparatus designed primarily for intensity measurements by direct photo-electric recording. A special feature is a high- intensity light source with four Toronto-type mercury arcs. It is possible to use a variety of sample volumes and to make measurements on samples over a wide range of temperatures both above and below room temperature. Semi-quantitative polarization measurements can also be made. The recording system uses an E. M. I. eleven-stage photomultiplier cell with a. c. amplification at 285 c/s, followed by rectification in a phase-sensitive homodyne circuit. The output is fed to a Cambridge recording potentiometer. Details of calibration for intensity measurements are given and sample records are shown illustrating the various applications of the apparatus.

Pump Light Source for Distributed Raman Amplification in MCFs With LD Sharing Circuit

2012 ◽  
Vol 24 (21) ◽  
pp. 1937-1940 ◽  
Author(s):  
K. Suzuki ◽  
H. Ono ◽  
T. Mizuno ◽  
Y. Hashizume ◽  
Y. Abe ◽  
...  
Keyword(s):  
Light Source ◽  
Pump Light ◽  
Raman Amplification

BMIT facility at the Canadian Light Source: Advances in X-ray phase-sensitive imaging

2016 ◽  
Vol 32 (12) ◽  
pp. 1753-1758 ◽  
Author(s):  
T.W. Wysokinski ◽  
J.P. Ianowski ◽  
X. Luan ◽  
G. Belev ◽  
D. Miller ◽  
...  
Keyword(s):  
Light Source ◽  
X Ray ◽  
Phase Sensitive

scholarly journals Theoretical and Experimental Investigation of the Effect of Pump Laser Frequency Fluctuations on Signal-to-Noise Ratio of Brillouin Dynamic Grating Measurement with Coherent FMCW Reflectometry

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2870
Author(s):  
Tatsuya Kikuchi ◽  
Ryohei Satoh ◽  
Iori Kurita ◽  
Kazumasa Takada
Keyword(s):  
Light Source ◽  
Signal To Noise Ratio ◽  
Experimental Result ◽  
Theoretical Formula ◽  
Pump Light ◽  
Signal To Noise ◽  
Technical Noise ◽  
Dynamic Grating ◽  
Frequency Fluctuations ◽  
Noise Ratio

Signal-dependent speckle-like noise has constituted a serious factor in Brillouin-grating based frequency-modulated continuous-wave (FMCW) reflectometry and it has been indispensable for improving the signal-to-noise ratio (S/N) of the Brillouin dynamic grating measurement to clarify the noise generation mechanism. In this paper we show theoretically and experimentally that the noise is generated by the frequency fluctuations of the pump light from a laser diode (LD). We could increase the S/N from 36 to 190 merely by driving the LD using a current source with reduced technical noise. On the basis of our experimental result, we derived the theoretical formula for S/N as a function of distance, which contained the second and fourth-order moments of the frequency fluctuations, by assuming that the pump light frequency was modulated by the technical noise. We calculated S/N along the 1.35 m long optical fiber numerically using the measured power spectral density of the frequency fluctuations, and the resulting distributions agreed with the measured values in the 10 to 190 range. Since higher performance levels are required if the pump light source is to maintain the S/N as the fiber length increases, we can use the formula to calculate the light source specifications including the spectral width and rms value of the frequency fluctuations to achieve a high S/N while testing a fiber of a given length.

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