Strong Atom-Photon Interaction for Microphotonic Devices

这项研究的目标是开发一种基于掺Er微腔的新型器件，这些微腔具有高效的光发射器、光子开关和太赫兹信号振荡器的功能。这些器件将利用强光子-原子相互作用的基本物理原理来确定在高Q微腔中使用掺Er介质作为光子器件设计的基本单元的可行性。这些器件的制造将涉及到结构和工艺指标的设计，如应力消除、层的平面性和均匀性以及材料体系的相稳定性。如果成功，这项研究将创造一种用于产生、检测和操纵光子的新设备，这可能对用于移动和管理信息的全光网络的发展至关重要。我们用SiO_2/SiO_2介质叠加镜包裹Er2 O_3微腔介质得到的初步结果表明，光子-原子耦合，室温下从微腔发射的光增强了几个数量级，以及光开关的能力。这种潜在的新型器件的Si/SiO_2微腔结构为实现与CMOS兼容的工艺和集成提供了一条非常重要的途径。此外，Si/SiO_2材料体系的高介电对比度(Dnr=2)意味着腔Qs为1000只需要4个层对。稀土元素作为量子点的类似物，在尺寸、单分散性和电子局部化方面具有极高的性能。在电信标准L=1.55微米波长范围内，Er具有发射光谱，是一种理想的稀土光学掺杂材料。发展Si：Er平台的主要障碍是稀土元素的原子共振光学截面小、辐射寿命长、调谐困难。我们建议使用单片平面微腔来增强Er光子的耦合，从而增加一个调谐振子强度的机制。Er_2O_3腔介质提供了高密度的原子，可以与光发生相干相互作用。这些相互作用的Er原子与它们的基质弱耦合，具有尖锐的发射线。这一特性产生了一种作为一组Er-光子耦合振荡器的对光作出响应的设备。通过调谐微腔谐振，可以将结构的发射、传输和反射特性控制在等于Er和腔谐振之间的频差的速度。我们提出了一项为期三年的工作，设计、制造和表征了用于在L=1.55微米波长范围内发射和开关光的室温操作器件。这项研究探索了一种新的将光子耦合到光学活性离子的装置平台，并将其应用于光的产生和控制。如果能够实现承诺的性能，那么这种Er：Si/SiO_2系统将提供一个高度可制造的、与硅兼容的光子器件平台。

The goal of the proposed research is to develop a new class of devices based on Er-doped microcavities that function as efficient light emitters, as photonic switches and as terahertz signal oscillators. The devices will exploit the basic physics of the strong photon-atom interaction to determine the feasibility of the using of Er-doped media in a high Q microcavity as a basic unit of photonic device design. The fabrication of these devices will involve the design of the structures and the process metrics, such as stress relief, planarity and uniformity of the layers and the phase stability of the materials systems. If successful, this research creates a new class of devices for the generation, detection and manipulation of photons that could be critical to the evolution of all optical networking for the movement and management of information. Our preliminary results obtained with an Er 2 O 3 microcavity medium clad by Si/SiO 2 dielectric stack mirrors showed direct evidence of photon-atom coupling, an enhancement of the light emitted from the microcavity by orders of magnitude at room temperature, and the capability of optical switching. The Si/SiO 2 microcavity structure of this potential new class of devices provides a very important route to CMOS compatible processing and integration. In addition, the high dielectric contrast of the Si/SiO 2 materials system (D nr=2) means that only four layer pairs are required for cavity Qs of 1000. Rare earth elements as quantum dot analogs offer the ultimate in size monodispersity and electronic localization. Erbium is an ideal rare earth optical dopant because of its emission spectrum in the telecommunications standard, l=1.55 micron wavelength region. The main obstacle to the development of a Si:Er platform is the small optical cross section, long radiative lifetime and difficulty of tuning of the atomic resonances of the rare earth elements. We propose to use monolithic planar microcavities to enhance the Er-photon coupling, and hence, add a mechanism for tuning of the oscillator strength. An Er2 O3 cavity medium provides a high density of atoms that can experience coherent interactions with light. These interacting Er atoms are weakly coupled to their host matrix with sharp emission lines. This property yields a device that responds to light as a set of Er-photon coupled oscillators. By tuning the microcavity resonance the emission, transmission and reflection properties of the structure may be controlled at speeds equivalent to the frequency difference between the Er and cavity resonances. We propose a three-year effort to design, fabricate and characterize room temperature operating devices for emission and switching of light in the l=1.55 micron wavelength region. The proposed study explores a new device platform of photon coupling to optically active ions and its application to the generation and control of light. If the promised performance can be achieved, then this Er:Si/SiO2 system will provide a highly manufacturable, silicon compatible photonic device platform.