A linear optical coupler for cryogenic detectors

Malatesta, M.; Perego, M. M.; Pessina, G.

doi:10.1016/s0168-9002(99)01347-9

Cited by 5 publications

(2 citation statements)

References 6 publications

(7 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, to suppress the single-mode fiber's polarization fading effect, a polarization diversity receiving device has been added. The splitting ratio of the optical couplers OC1 is 95/5, OC2 is 99/1, and OC3, OC4, and OC5 are all 3 dB optical couplers, meaning that the splitting ratios are 50/50 for these couplers (Malatesta et al 2000). To ensure that the wavelength scanning of the light source is synchronized with the data acquisition, the TTL trigger signal of the TSL-710 can be used as an external trigger signal for the data acquisition card.…”

Section: Composition Of the Demodulatormentioning

confidence: 99%

Research and application of an improved internal thrust force measurement system for rock and soil mass based on OFDR

Wang

Liu

2021

Geomatics, Natural Hazards and Risk

View full text Add to dashboard Cite

Internal thrust force of unstable rock and soil mass is an essential parameter for prediction of many geological hazard. Currently, fiber bragg grating (FBG) and optical time-domain reflectometer (OTDR) are widely used to measure internal stress of unstable rock and soil mass. However, these methods have disadvantages such as low spatial resolution and the paucity of distributed measurements. This paper develops a quasi-distributed thrust measurement system based on an optical frequency domain reflectometer (OFDR). Firstly, we design an optical fiber stress sensor head using the characteristics of the optical fiber microbending effect. And then, the cubic spline interpolation method is used to compensate for the nonlinear effects of the OFDR. Finally, we implement a laboratory experiment of lateral stress to make error calibration. As a result, the OFDR sensing system achieved a spatial resolution of 20 cm by using a 500 m test fiber, maximum measurement pressure reached 1.059 MPa and relative error is 8.9%. We implemented OFDR in the Chenjiagou landslide located at the Three-Gorge of Chongqing in China. The results showed that this system can accurately locate six fiber stress sensors within the landslide over a range of 0 $ 420 m, obtaining the lateral thrusts as well.

show abstract

Section: Composition Of the Demodulatormentioning

confidence: 99%

Research and application of an improved internal thrust force measurement system for rock and soil mass based on OFDR

Wang

Liu

2021

Geomatics, Natural Hazards and Risk

View full text Add to dashboard Cite

show abstract

“…To improve the signal-to-noise ratio of the coherent OFDR signals, the balanced detector used is a Thorlabs PDB430C with a bandwidth of 350 MHz; the acquisition card uses a Spectrum M4i.4421 with four channels and the highest sampling rate for each channel is 250 MHz. Additionally, to suppress the polarization fading effect of the single-mode fiber, a polarization diversity receiving device has been added, 125 the splitting ratio of the optical couplers OC1 is 95/5, OC2 is 99/1, and OC3, OC4, and OC5 are all 3 dB optical couplers, meaning that the splitting ratios are 50/50 for these couplers (Malatesta et al, 2000). To ensure that the wavelength scanning of the light source is synchronized with the data acquisition, the TTL trigger signal of the TSL-710 can be used as an external trigger signal for the data acquisition card.…”

mentioning

confidence: 99%

Research and Application of an Inner Thrust Measurement System for Rock and Soil Masses based On OFDR

Liu

Wang²,

Wang³

et al. 2020

Preprint

View full text Add to dashboard Cite

For measuring internal stresses in rock and soil masses, specifically on unstable slopes, the fiber Bragg grating (FBG) and optical time-domain reflectometer (OTDR) methods based on fiber sensing technology have disadvantages such as low spatial resolution, low measurement accuracy, and non-distributed measurements. This paper presents a quasi-distributed 10 thrust measurement system based on an optical frequency domain reflectometer (OFDR). First, the optical fiber stress sensing head was designed based on the micro-bending effect of the optical fiber, the cubic spline interpolation method was then used to compensate for the nonlinear effects of the OFDR stress sensing system, the compensation effects of different software methods were compared and analyzed simultaneously, which significantly improved the resolution and spatialpositioning capabilities of the OFDR sensing system, and error calibration was then performed through laboratory 15 experiments of lateral stress. The test results showed that the OFDR sensing system achieved a spatial resolution of 20 cm using a 500 m test fiber (the resolution of an OTDR sensing system is generally approximately 1 m), the maximum measurement pressure can reach 1.059 MPa and the maximum relative error is 8.9%. Finally, the field engineering application was carried out in the Chenjiagou landslide in Fengjie County, Chongqing City, Three Gorges Dam, China. The application results showed that the system can accurately locate six fiber optic micro-bending stress sensors installed within 20 the landslide body over a range of 0~420 m and can obtain the pressure values of their lateral thrusts. This system is a quasidistributed stress monitoring instrument that provides long measurement distances, high spatial resolutions, high sensitivities, and fast responses that can be used for unstable slopes, slope engineering, water conservation and hydropower dams, and tunnel chambers, and thus, has good engineering application prospects in the safety monitoring field.

show abstract

Signals, Systems, Noise, and Interferences

2017

Signal Processing for Radiation Detectors

View full text Add to dashboard Cite

A linear optical coupler for cryogenic detectors

Cited by 5 publications

References 6 publications

Research and application of an improved internal thrust force measurement system for rock and soil mass based on OFDR

Research and application of an improved internal thrust force measurement system for rock and soil mass based on OFDR

Research and Application of an Inner Thrust Measurement System for Rock and Soil Masses based On OFDR

Signals, Systems, Noise, and Interferences

Contact Info

Product

Resources

About