Optical Waveguide BTX Gas Sensor Based on Polyacrylate Resin Thin Film

Abstract

An optical sensor sensitive to BTX has been developed by spin coating a thin film of polyacrylate resin onto a tin- diffused glass optical waveguide. A pair of prism coupler was employed for optical coupling matched with diiodomethane (CH2l2). The guided wave transmits in waveguide layer and passes through the film as an evanescent wave. Polyacrylate film has a strong capacity of absorbing oil gases. The film is stable in N2 but benzene exposure at room temperature can result in rapid and reversible changes of transmittance (7) and refractive index (n1) of this film. It has been demonstrated that the sensor containing a 10 mm boardand about a hundred nanometers thick resin film can detect lower than 8 ppm BTX.

Detection of Trimethylamine Based on a Manganese Tetraphenylporphyrin Optical Waveguide Sensing Element

“…The light entered into the propagating layer according the prism coupling method 29,34 In addition, part of the light would enter the sensitive film in the form of evanescent waves when the light propagates in the waveguide layer. 35 And when the target gas would flow into the small chamber and be exposed with the sensitive layer, as a result the output light intensity would change. The photomultiplier converts the optical signal into an electrical signal and is recorded by computer.…”

Optical-Electricity Gas-Sensing Property Detection of SDBS-WO3 Film at Room Temperature

“…The planar OWG sensor element consists of cladding, a wave layer, and a substrate. When the laser beam (λ = 532 nm) was coupled into the waveguide layer by a prism (glass prism, n = 1.78; matching liquid of diiodomethane as matching liquid, n = 1.74), 25,26 light in the guided wave layer appeared in the form of the total reflection of the evanescent wave getting into the sensitive layer. 27 When analytes were injected into the flow cell and exposed to the sensitive layer, the evanescent wave intensity changed, which led to a change in the output light intensity.…”

Application Progress of Optical Waveguide Sensor in the Gas Detection

“…。近 年来，国内外先后研制出各种光波导气体传感器 [3][4][5][6] ， 光波导离子传感器 [7,8] ，光波导湿度传感器 [9] ，光波导 生物传感器 [10] 和物理传感器 [11] 等等。光波导传感器 光波导传感器在气体检测中的应用进展 具有更有利于实现多功能集成，紧凑封装和批量生 产，低耗高效，容易实现在线检测等一系列跟其他结 构的传感器无法比拟的优势。玻璃光波导传感元件作 为新一代微型化、集成化和智能化传感器系统的重要 组成部分，在传感器领域中占有越来越重要的地位 [12,13] 。 平面光波导(OWG)由覆盖层， 衬底(substrate)和导 波层(waveguide layer)所组成 [14] ， 覆盖层通常指的是空 …”