NEW CONCEPT FOR CONTROLLING MODES IN A FABRY-PEROT

法布里-珀罗由两个平行反射镜组成，用于定义激光器中的模式、可调谐滤波器、频谱分析仪和一些调制器。反射镜通常是介电四分之一波堆栈，在整个厚度上以分布式方式反射。该项目的目的是证明，有效穿透长度到四分之一波叠反射镜（也称为分布式布拉格反射镜）可以变得大而负，零，或大而正，取决于仔细控制折射率。这一概念将应用于：a)生产单模半导体激光器和b)研究高速空间光调制器。智力优势：该项目源于对这些分布式反射镜的有效穿透长度的一种新的解析解决方案，并在解决方案中发现了极点和零。这些制度的存在已通过计算机检查，并暗示了一些重要的应用在光学器件和系统。定义和演示这些应用程序是一项令人兴奋的挑战。例如，这将是第一次通过控制反射镜的折射率来控制法布里-珀罗模式间距。此外，负穿透长度意味着超光反射，这是解释和寻找应用的重要智力挑战。为了达到这种高反射率的状态，需要将分布式反射器沉积在金属（或金属膜）上或使用大量的层对。在任何一种情况下，都需要仔细控制薄膜的折射率。这是将在实验室进行的技术挑战。它将借助作者于1983年介绍的薄膜测量技术，并将使用达特茅斯大学开发的薄膜沉积技术。更广泛的影响：控制分布式反射镜的有效穿透长度提供了广泛的应用。这些包括：廉价的单模半导体激光器，每脉冲功率更高的锁模半导体激光器，更简单的光纤法布里-珀罗可调谐滤波器的制造，实用的可变光衰减器，更好的法布里-珀罗光学传感器，更简单的VCSEL制造和谐振光探测器。最后，非线性和电驱动波导调制器和空间光调制器变得实用。这里首创的概念也可以用于实现波导的平面内直角弯曲，这通常需要纳米结构光子带隙材料。这项研究也将对培养工程人才产生积极的影响，因为p.i.是一名女性，博士研究生提议发起这项研究也是一名女性。达特茅斯学院从事最先进的研究，为教学研究机构提供了一个典范。

A Fabry-Perot consists of two parallel mirrors used to define modes in lasers, tunable filters, spectrum analyzers, and some modulators. The mirrors are usually dielectric quarter wave stacks that reflect in a distributed way, throughout their thickness. The objective of this project is to demonstrate that the effective penetration length into the quarter wave stack mirror (also called a distributed Bragg reflector) can become large and negative, zero, or large and positive, depending on careful control of the refractive indices. This concept will then be applied to: a) producing single mode semiconductor lasers and b) investigating high speed spatial light modulators.Intellectual merit: this project stems from a new analytic solution to the effective penetration length in these distributed mirrors and the discovery of both a pole and a zero in the solution. The existence of these regimes has been checked by computer and implies a number of important applications in optical devices and systems. Defining and demonstrating these applications is the exciting challenge. For example, this will be the first time that control of a Fabry-Perot mode spacing is achieved by controlling the refractive index in its mirrors. Furthermore, a negative penetration length implies superluminal reflection, which is an important intellectual challenge to explain and find applications for.To achieve this regime with high reflectivity requires the distributed reflector be deposited on metal (or a metal film) or to use a large number of layer-pairs. In either case, careful control of the refractive indices of the films is required. This is the technical challenge that will be undertaken in the laboratory. It will be helped by a thin film measurement technique introduced by author in 1983 and will use a thin film deposition technology that was developed at Dartmouth.Broader impact: Controlling the effective penetration length of a distributed mirror offers a wide range of applications. These include: inexpensive single mode semiconductor lasers, mode-locked semiconductor lasers with more power per pulse, simpler fabrication of fiber Fabry-Perot tunable filters, a practical variable optical attenuator, better Fabry-Perot optical sensors, simpler fabrication of VCSEL's, and resonant photo-detectors. Finally, nonlinear and electrically driven waveguide modulators and spatial light modulators become practical. The concept pioneered here can also be used to achieve in-plane right angle bends in waveguides, which usually requires nanostructure photonic bandgap materials.This research will also have a positive impact on training engineering personnel, since the P. I. is a woman and the Ph. D. graduate student proposed to initiate the research is also a woman. Dartmouth as a college is involved in state-of-the-art research and provides a model for teaching-research institutions.