發(fā)布時(shí)間：2018-12-20 10:19

【摘要】：在眾多檢測(cè)領(lǐng)域,液位和溫度的傳感檢測(cè)占據(jù)著重要地位,相應(yīng)的檢測(cè)手段也多種多樣。相比于傳統(tǒng)電類傳感器,光纖傳感器所具有的傳感優(yōu)勢(shì)使得其發(fā)展迅速且應(yīng)用廣泛。其中,單模光纖偏芯熔接所形成的模間干涉與Sagnac環(huán)相搭配,用于相關(guān)環(huán)境參量的傳感可以得到高干涉消光比,更高的干涉消光比可得到更高的測(cè)量靈敏度,故而使其成為了光纖傳感領(lǐng)域的熱點(diǎn)研究方向。本文研究基于Sagnac環(huán)的單模偏芯光纖經(jīng)U型彎曲改造所形成的傳感器,對(duì)其各項(xiàng)特性進(jìn)行實(shí)驗(yàn)研究分析,并進(jìn)一步研究其液位和溫度的測(cè)量應(yīng)用。該傳感器成本低廉、制作簡(jiǎn)單、操作方便,有著較好的應(yīng)用前景。本文的工作主要包括以下內(nèi)容:1、介紹光纖傳感和相關(guān)理論分析。(1)介紹論文的研究背景及意義、光纖的分類、光纖傳感器的分類、干涉型光纖傳感器的優(yōu)點(diǎn)、目前光纖傳感器所面臨的主要問(wèn)題及國(guó)內(nèi)外研究概況。(2)介紹單模偏芯光纖干涉型傳感器模間干涉的相關(guān)理論。(3)理論說(shuō)明Sagnac環(huán)可提高干涉消光比,并經(jīng)實(shí)驗(yàn)驗(yàn)證。2、對(duì)本文的傳感器的多項(xiàng)特性做實(shí)驗(yàn)分析。傳感器結(jié)構(gòu)特性:(1)基于Sagnac環(huán)單模偏芯光纖傳感器的實(shí)驗(yàn)干涉圖譜與偏芯熔接點(diǎn)個(gè)數(shù)、Sagnac環(huán)的形狀密切相關(guān)。(2)單位波長(zhǎng)段內(nèi)的波谷個(gè)數(shù)與傳感臂的長(zhǎng)度密切相關(guān),而熔接點(diǎn)偏芯量及Sagnac環(huán)的形狀對(duì)其不存在明顯影響。傳感器傳感特性:(1)溫度的變化使得該傳感器干涉譜線發(fā)生變動(dòng)。(2)傳感器所受壓力的變化不會(huì)對(duì)干涉譜線造成大的影響。(3)經(jīng)仿真模擬,包層處光功率的損耗會(huì)隨外界折射率增大而增大。另外,傳感器經(jīng)長(zhǎng)時(shí)間浸泡,干涉譜線功率會(huì)持續(xù)下降,但隨著時(shí)間的推移而穩(wěn)定下來(lái),各波谷中心波長(zhǎng)沒(méi)隨時(shí)間的增加有顯著的波動(dòng)。3、為了進(jìn)一步探究該傳感器,將該傳感器用于液位和溫度的測(cè)量研究。實(shí)驗(yàn)表明:這兩個(gè)環(huán)境參量與干涉波谷中心波長(zhǎng)存在著良好的傳感響應(yīng)關(guān)系。利用相應(yīng)的方法減弱了實(shí)驗(yàn)中的粗大誤差,避免了挑選波谷,提高了實(shí)驗(yàn)效率。實(shí)驗(yàn)數(shù)據(jù)經(jīng)相應(yīng)方法處理后,液位靈敏度為1.72nm/cm,溫度靈敏度為0.689 nm/℃。
[Abstract]:In many fields, the sensor detection of liquid level and temperature occupies an important position, and the corresponding detection methods are also various. Compared with traditional electrical sensors, optical fiber sensors have the advantages of rapid development and wide application. Among them, the interference formed by single-mode fiber core splicing is matched with the Sagnac ring, and the sensor used for the related environmental parameters can obtain high interference extinction ratio, and the higher interference extinction ratio can get higher measurement sensitivity, and the higher the interference extinction ratio is, the higher the measurement sensitivity is, and the higher the interference extinction ratio is, the higher the measurement sensitivity is. Therefore, it has become a hot research direction in the field of optical fiber sensing. In this paper, the sensor based on Sagnac ring is studied, which is formed by U-shaped bending modification of single-mode biased fiber. The characteristics of the sensor are analyzed experimentally, and the application of liquid level and temperature measurement is further studied. The sensor has the advantages of low cost, simple fabrication and convenient operation. The main contents of this paper are as follows: 1. Introduce the optical fiber sensor and related theoretical analysis. (1) introduce the research background and significance of the paper, the classification of optical fiber, the classification of optical fiber sensor, the advantages of interferometric optical fiber sensor, The main problems faced by optical fiber sensors and the research situation at home and abroad are introduced. (2) the theory of intermodal interference of single-mode bias fiber interferometric sensor is introduced. (3) the theory shows that Sagnac loop can improve the extinction ratio of interference. And through the experimental verification. 2, the sensor's many characteristics are analyzed experimentally. The structural characteristics of the sensor are as follows: (1) based on the experimental interference pattern of the Sagnac ring single-mode bias fiber sensor and the number of core fused contact points, the shape of the Sagnac ring is closely related to the shape of the Sagnac ring. (2) the number of troughs in the unit wavelength band is closely related to the length of the sensing arm. However, the amount of core deviation and the shape of the Sagnac ring have no obvious influence on it. Sensor sensing characteristics: (1) the temperature change makes the sensor interference spectrum line change. (2) the change of the sensor pressure will not have a great impact on the interference spectrum line. (3) after simulation, The loss of optical power in the cladding increases with the increase of refractive index. In addition, after a long immersion, the power of the interference line will continue to decrease, but with the passage of time, the central wavelength of each trough does not fluctuate significantly with the increase of time. 3, in order to further explore the sensor, The sensor is used to measure the liquid level and temperature. The experimental results show that there is a good sensing response relationship between the two environmental parameters and the central wavelength of the interference trough. By using the corresponding method, the gross error in the experiment is reduced, the selection of troughs is avoided, and the experimental efficiency is improved. After the experimental data were processed by the corresponding method, the liquid level sensitivity was 1.72 nm / cm and the temperature sensitivity was 0.689 nm/ 鈩，

本文編號(hào)：2387852