Fiber optic Fabry-Perot sensors for high-speed heat transfer measurements

1991 ◽  
Author(s):  
Stephen R. Kidd ◽  
Pranay G. Sinha ◽  
James S. Barton ◽  
Julian D. C. Jones
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Fiber Optic ◽  
Fabry Perot

Fiber-Optic Extrinsic Fabry-Perot Interferometer Sensors with Multi-Wavelength Intensity Demodulation

2013 ◽  
Vol 470 ◽  
pp. 630-635 ◽  
Author(s):  
Ning Fang Song ◽  
Rui Qi Cui ◽  
Yu Jie Yang ◽  
Xiao Liang Xu
Keyword(s):  
Incident Wave ◽  
High Speed ◽  
Cavity Length ◽  
Fiber Optic ◽  
Wave Length ◽  
Fabry Perot ◽  
Multiple Wavelengths ◽  
Large Scope ◽  
Multi Wavelength ◽  
Novel Method

In this paper, a novel method used for Fabry-Perot cavity length's demodulation in high-speed and large scope measurement was proposed. Principle of the method is based on uniqueness of intensity of multiple wavelengths in the scope of Fabry-Perot vibration. This technique offers flexibility of selecting incident wave length and enhances the scope of demodulation of cavity length, compared with that popular triple wave length demodulation. In experiment, multi-wavelength demodulation is demonstrated for measurement of cavity length varying from 110um to 115um and the strain resolution was higher than 0.1um.

scholarly journals A High-Speed Demodulation Technology of Fiber Optic Extrinsic Fabry-Perot Interferometric Sensor Based on Coarse Spectrum

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6609
Author(s):  
Peng Zhang ◽  
Ying Wang ◽  
Yuru Chen ◽  
Xiaohua Lei ◽  
Yi Qi ◽  
...  
Keyword(s):  
Real Time ◽  
High Speed ◽  
Cavity Length ◽  
Fiber Optic ◽  
Likelihood Estimation ◽  
Time Dynamic ◽  
Wavelength Division ◽  
Broadband Spectrum ◽  
Fabry Perot ◽  
Interferometric Sensor

A fast real-time demodulation method based on the coarsely sampled spectrum is proposed for transient signals of fiber optic extrinsic Fabry-Perot interferometers (EFPI) sensors. The feasibility of phase demodulation using a coarse spectrum is theoretically analyzed. Based on the coarse spectrum, fast Fourier transform (FFT) algorithm is used to roughly estimate the cavity length. According to the rough estimation, the maximum likelihood estimation (MLE) algorithm is applied to calculate the cavity length accurately. The dense wavelength division multiplexer (DWDM) is used to split the broadband spectrum into the coarse spectrum, and the high-speed synchronous ADC collects the spectrum. The experimental results show that the system can achieve a real-time dynamic demodulation speed of 50 kHz, a static measurement root mean square error (RMSE) of 0.184 nm, and a maximum absolute and relative error distribution of 15 nm and 0.005% of the measurement cavity length compared with optical spectrum analyzers (OSA).

scholarly journals Multichannel Fiber-Optic Silicon Fabry–Pérot Interferometric Bolometer System for Plasma Radiation Measurements

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 344
Author(s):  
Nezam Uddin ◽  
Qiwen Sheng ◽  
Seungsup Lee ◽  
Matthew L. Reinke ◽  
David Donovan ◽  
...  
Keyword(s):  
High Speed ◽  
Fiber Optic ◽  
Light Emission ◽  
Single Channel ◽  
Single Mode ◽  
System Optimization ◽  
The Other ◽  
Plasma Radiation ◽  
Fabry Perot ◽  
High Finesse

A single-channel fiber-optic bolometer system based on a high-finesse silicon Fabry–Pérot interferometer (FPI) was previously reported, intended to measure plasma radiation from the magnetically confined fusion chamber. Recently, we developed a multichannel fiber-optic bolometer system with five bolometers multiplexed using a coarse wavelength division multiplexer (CWDM) and interrogated with a white-light system involving a superluminescent light-emission diode source and a high-speed spectrometer. One of the bolometers was used as the reference bolometer to compensate for the ambient temperature variations, and the other four bolometers were used for radiation measurement. The bolometers have a simple structure with a silicon pillar at the end of the single-mode fiber and a gold disk on the other side of the silicon pillar. They are also easy to fabricate without stringent requirements on the optical alignment. Analysis of the system optimization was performed to improve the noise performance and to mitigate the vibration effect that may present in the practical application. The system had a significantly enhanced measurement range compared to the previous high-finesse FPI bolometer system for measuring radiation. Test results performed in air using a 405 nm laser as the radiation source showed that the temperature resolution and the noise-equivalent power density of the sensing bolometers connected to each channel of the CWDM were, respectively, ~0.4 mK and ~0.1 W/m2, with a time constant of ~220 ms, which is comparable to the previous more complicated fiber-optic bolometer systems based on high-finesse FPIs that were interrogated using wavelength-scanning lasers.

Tributary Mapping Multiplexing an Efficient Technique for High Speed Fiber Optic Communication

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Usman Illahi ◽  
Javed Iqbal ◽  
Muhammad Ismail Sulaiman ◽  
Muhammad Alam ◽  
Mazliham Mohd Su'ud
Keyword(s):  
Spectral Efficiency ◽  
High Speed ◽  
Fiber Optic ◽  
Single Channel ◽  
Efficient Technique ◽  
High Dispersion ◽  
Optical Filtering ◽  
Fiber Optic Communication ◽  
Optic Communication ◽  
Dispersion Tolerance

<p>A novel technique of multiplexing called Tributary Mapping Multiplexing (TMM) is<br />applied to a single channel wavelength division multiplexing system and performance is monitored on the basis of simulation results. To elaborate the performance of TMM in this paper, a 4-User TMM system over single wavelength channel is demonstrated. TMM showed significant tolerance against narrow optical filtering as compared to that of conventional TDM at the rate of 40 Gbit/s. The above calculations are made by optical filter bandwidth and dispersion tolerance that was allowed at minimum. The spectral efficiency achieved by this TMM was 1 b/s/Hz and it was executed by using transmitters and receivers of 10 Gbit/s without polarized multiplexing. The high spectral efficiency, high dispersion tolerance and tolerance against strong optical filtering makes TMM an efficient technique for High<br />Speed Fiber Optic Communication.</p>

scholarly journals Low-pressure and liquid level fiber‐optic sensor based on polymeric Fabry–Perot cavity

2021 ◽  
Vol 53 (5) ◽  
Author(s):  
D. Jauregui-Vazquez ◽  
M. E. Gutierrez-Rivera ◽  
D. F. Garcia-Mina ◽  
J. M. Sierra-Hernandez ◽  
E. Gallegos-Arellano ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Low Pressure ◽  
Fiber Optic Sensor ◽  
Liquid Level ◽  
Optic Sensor ◽  
Fabry Perot

Experimental investigation of wall heat transfer due to spray combustion in a high-pressure/high-temperature vessel

2021 ◽  
pp. 146808742110072
Author(s):  
Karri Keskinen ◽  
Walter Vera-Tudela ◽  
Yuri M Wright ◽  
Konstantinos Boulouchos
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
High Temperature ◽  
High Speed ◽  
Transfer Problem ◽  
Wall Heat Transfer ◽  
Gas Temperature ◽  
Reference Case ◽  
High Pressure High Temperature

Combustion chamber wall heat transfer is a major contributor to efficiency losses in diesel engines. In this context, thermal swing materials (adapting to the surrounding gas temperature) have been pinpointed as a promising mitigative solution. In this study, experiments are carried out in a high-pressure/high-temperature vessel to (a) characterise the wall heat transfer process ensuing from wall impingement of a combusting fuel spray, and (b) evaluate insulative improvements provided by a coating that promotes thermal swing. The baseline experimental condition resembles that of Spray A from the Engine Combustion Network, while additional variations are generated by modifying the ambient temperature as well as the injection pressure and duration. Wall heat transfer and wall temperature measurements are time-resolved and accompanied by concurrent high-speed imaging of natural luminosity. An investigation with an uncoated wall is carried out with several sensor locations around the stagnation point, elucidating sensor-to-sensor variability and setup symmetry. Surface heat flux follows three phases: (i) an initial peak, (ii) a slightly lower plateau dependent on the injection duration, and (iii) a slow decline. In addition to the uncoated reference case, the investigation involves a coating made of porous zirconia, an established thermal swing material. With a coated setup, the projection of surface quantities (heat flux and temperature) from the immersed measurement location requires additional numerical analysis of conjugate heat transfer. Starting from the traces measured beneath the coating, the surface quantities are obtained by solving a one-dimensional inverse heat transfer problem. The present measurements are complemented by CFD simulations supplemented with recent rough-wall models. The surface roughness of the coated specimen is indicated to have a significant impact on the wall heat flux, offsetting the expected benefit from the thermal swing material.

Sign in / Sign up

Export Citation Format

Share Document