CAREER: A Program for Research and Education in Fiber-OpticsInvolving Fabrication of Novel Bragg-Grating Devices and Sensors

9701538 Sharma该提案涉及使用光纤布拉格光栅制造新设备和传感器。 虽然反射布拉格光栅的特性是相当好理解的，但对于抽头布拉格光栅并非如此。 建议在此进行。 将制作一种由两个并排的抽头布拉格光栅组成的新型定向耦合器。 将探讨它作为波长敏感光锥的应用。 串联制造的这种装置的数量将是有用的智能结构中的横向应变的分布式传感。 这样的传感器将通过串联的反射布拉格光栅补充公知的纵向应变的分布式感测。 反射布拉格光栅还将用于制造化学传感器，用于在一种新的相关光谱学装置中感测环境气体，如NH3、H2O和CH 4，其中光栅将取代笨重的参考池。 利用光栅设置，可以获得气体吸收线和布拉格波长之间的相关性的100%调制，这不同于如在常规相关光谱中通过斯塔克位移和谱线加宽的部分调制。 该技术将用于环境气体的分布式传感。 这将在监测和控制大气污染领域有重要的应用。 学生将成为提案中描述的所有研究活动的组成部分。 在拟议的综合计划的四年期间的任何时候，一个博士学位。学生将参与研究，努力获得应用物理学学位。 该大学有一个工作/学习计划，为本科生工作对他们的物理/工程学位。 学生通常担任研究助理，并支付他的学费和其他费用。 在任何时候，拟议的研究将支持一个本科生以及，协助研究生在他/她的研究。 最后，该提案描述了一个针对高中生的学徒计划，他们将在暑期花4-6周的时间在光纤实验室中获得基本设备的实践经验。 ***

9701538 Sharma The proposal deals with fabrication of new devices and sensors using fiber-optic Bragg gratings. While the characteristics of reflection Bragg gratings is quite well understood, this is not so for tapped Bragg gratings. This is proposed to be done here. A novel directional coupler consisting of two tapped Bragg gratings side-by-side will be fabricated. Its application as a wavelength sensitive light-tap will be inveqtigated. A number of such devices fabricated in series will be useful for distributed sensing of transverse strain in Smart Structures. Such a sensor will compliment the well known distributed sensing of longitudinal strain by reflection Bragg gratings in series. Reflection Bragg gratings will also be used to fabricate a chemical sensor for sensing environmental gases like NH3, H2O and CH4 in a novel correlation spectroscopy set up where a grating will replace the cumbersome bulky reference cell. With the grating set up 100% modulation of correlation between the gas absorption lines and the Bragg wavelength can be obtained unlike partial modulation by Stark shift and broadening of spectral lines as in conventional correlation spectroscopy. This technique will be used for distributed sensing of environmental gases. This will have important applications in the area of monitoring and control of atmospheric pollution. Students will be an integral part of all research activity described in the proposal. At any time over the four year duration of the proposed integrated plan one Ph.D. student will be involved in the research, working towards his/her degree in applied physics. The University has a work/study program for undergraduate students working towards their physics/engineering degrees. A student typically works as a research assistant and is paid to cover his tuition and other expenses. At any given time the proposed research will support one undergraduate student as well, assisting a graduate student in his/her research. Finally, the proposal d escribes an apprenticeship program for high school students in which they will spend 4-6 weeks of their summer getting a hands-on experience with basic devices in a fiber-optics laboratory. ***