Fujian Castech Crystals. Inc.

Fuzhou, China

Fujian Castech Crystals. Inc.

Fuzhou, China
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Wang W.,Guangdong Ocean University | Wang W.,Dalian University of Technology | Jiang X.,Fujian Castech Crystals Inc.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2012

A novel high sensitivity diaphragm-based extrinsic Fabry-Pérot (FP) interferometric fiber-optic pressure sensor with back-pressure equilibrium structure is present. The sensor possesses backpressure-independence and small temperature-dependence. The ultra-thin fused silica is bonded to the end surface of the double holes fused silica ferrule by use of CO 2 laser, and the double holes structure enhances the sensor performance. The operating point does not drift. The sensor with sensitivity of 9.51 nm/kPa (65.57 nm/psi) has been achieved.


Wang W.,Dalian University of Technology | Wang W.,Guangdong Ocean University | Yu Q.,Dalian University of Technology | Jiang X.,Fujian Castech Crystals. Inc.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2012

The study on the heating fusion welding between the ultra-thin fused silica glass with 25 μm-thickness and the end face of the fused silica capillary tube is carried by using low power CO2 pulse laser with a pulse frequency of 40 kHz. The duty ratio, the defocus laser preheating and the defocus laser annealing impacting on the heating fusion welding of the fused silica glass are researched and analyzed. The results show that a duty ratio of 37% can perform perfectly the no penetration, sealing and firm welding between the ultra-thin fused silica glass and the fused silica capillary tube. For the welding without crack or split of the ultra-thin fused silica glass, the preheating of the +2 mm defocus pulse laser with a duty ratio of 20% plays a key role. The annealing of the -2 mm defocus pulse laser with an appropriate duty ratio can release the residual thermal stress produced in the process of the heating fusion welding in the ultra-thin fused silica glass, enhancing the performance of the fused silica device. The pressure and temperature linearity of the fiber-optic Fabry-Pérot sensor welded perfectly by the CO2 laser are 0.9995 and 0.9991, respectively, and their repeatabilities are good.


Wang Q.,Dalian University of Technology | Wang W.,Dalian University of Technology | Wang W.,Guangdong Ocean University | Jiang X.,Fujian Castech Crystals Inc. | Yu Q.,Dalian University of Technology
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

A new structure of diaphragm-based extrinsic Fabry-Perot interferometric (EFPI) optical fiber sensor is presented. A double holes silica ferrule with 1.8mm outside diameter is used to align the fiber. The Fabry-Perot (F-P) cavity is formed between the fiber end facet and inner surface of the diaphragm. The diaphragm is attached to the top of ferrule by carbon dioxide (CO2) laser thermal fusion bonding system. One hole of ferrule is used to align the fiber to the diaphragm and the other is used to balance the pressure inside and outside of F-P cavity. The diameter of the sensor head is only 1.8mm. In the pressure measurement, the pressure sensitivity of this sensor is about 25.89nm/KPa and the temperature dependence is approximately 6nm/°C. The sensor has a linear response in the range from 0 to 3KPa. This structure of sensor can eliminate the thermally induced inner pressure changes of F-P cavity. Furthermore, the sensor with the temperature compensate can be used to detect the liquid level. The fabrication of this kind sensor is simple and low cost. And the advantages of this sensor are high sensitivity, immune to electromagnetic interference (EMI) and high temperature resistance. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Wang W.,Guangdong Ocean University | Wang W.,Dalian University of Technology | Jiang X.,Fujian Castech Crystals Inc. | Yu Q.,Dalian University of Technology
Optics Communications | Year: 2012

A high performance multiplexed fiber-optic sensor consisted of diaphragm-based extrinsic Fabry-Perot interferometer (DEFPI) and fiber Bragg grating (FBG) is proposed. The novel structure DEFPI fabricated with laser heating fusion technique possesses high sensitivity with 5.35 nm/kPa (36.89 nm/psi) and exhibits ultra-low temperature dependence with 0.015 nm/°C. But the ultra-low temperature dependence still results in small pressure measurement error of the DEFPI (0.0028 kPa/°C). The designed stainless epoxy-free packaging structure guarantees the FBG to be only sensitive to temperature. The temperature information is created to calibrate the DEFPI's pressure measurement error induced by the temperature dependence, realizing effectively temperature self-compensation of the multiplexed sensor. The sensitivity of the FBG is 10.5 pm/°C. In addition, the multiplexed sensor is also very easy to realize the pressure and the temperature high-precise high-sensitive simultaneous measurement at single point in many harsh environmental areas. © 2012 Elsevier B.V. All rights reserved.


Wenhua W.,Guangdong Ocean University | Xinsheng J.,Fujian Castech Crystals Inc
Applied Mechanics and Materials | Year: 2013

In this paper, the influence of the Q point on the DEFPI fiber-optic sensors is comprehensively analyses. For a DEFPI fiber-optic sensor, the output signals vary with the different position of the operational point regarding to the same applied pressure. The optimal operational point is in the middle position of the fringe linear scope. In addition, we present a novel structure sensor to guarantee the stableness of the Q point. © (2013) Trans Tech Publications, Switzerland.


Wang W.,Dalian University of Technology | Wang W.,Guangdong Ocean University | Yu Q.,Dalian University of Technology | Jiang X.,Fujian Castech Crystals Inc.
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2012

Optical fiber sensors for ultrasonic signals detection have become a research focus in the past years. In this paper, a novel structure of the diaphragm-based extrinsic Fabry-Pérot interferometric (DEFPI) optical fiber ultrasonic sensor with a through vent hole of the fused silica ferrule was present. In this sensor system, the amplified spontaneous emission (ASE) optical source and the Fabry-Pérot filter are used to adjust the wavelength of the operation point of the sensor. We performed the ultrasonic distance detection experiment from 1 cm to 31 cm and the sensor sensitivity experiment, and the pressure sensitivity of the sensor is 9.68 nm/kPa (66.69 nm/psi). The sensitivity of the fusion silica structure DEFPI optical fiber is much higher than that of the HCPCF-ILFP (hollow-core photonic crystal fiber in-line fiber-optic Fabry-Pérot) and the fiber Bragg grating (FBG).


Wang W.,Dalian University of Technology | Wang W.,Guangdong Ocean University | Yu Q.,Dalian University of Technology | Li F.,Dalian University of Technology | And 2 more authors.
IEEE Sensors Journal | Year: 2012

A novel high sensitivity pressure sensor based on all-fused-silica extrinsic Fabry-Pérot optical fiber interferometer, which exhibits extreme low temperature dependence, has been developed. The sensor can approach a sensitivity of 5.18 nm/KPa (35.72 nm/psi), a resolution of 38 Pa (0.005 psi). Due to epoxy-free bonding and reserving a vent hole between the fiber and the ferrule in the process of laser heating fusion bonding, the temperature dependence is significantly reduced to the 0.011 nm/°C, and pressure measurement error is limited within 0.0021 KPa/°C (0.0003 psi°C). The operating point does not shift with backpressure change due to the vent hole. The sensor is able to be used in the liquid measurement, environmental monitoring, and other industrial applications in harsh environment. © 2012 IEEE.

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