Two-Dimensional Leaky-Mode VCSEL Arrays: Active Photonic Lattices

在这项工作中，PI将利用紧密间隔的漏模VCSEL的二维阵列的模式选择性特性来实现空间相干光源。二维密集反导引垂直腔面发射激光器阵列为研究有源光子晶格的光学模式特性提供了一个独特的平台。他提出了对这种光子晶格结构支持的漏模的第一个全面的阈值以上研究。二维有源光子晶格允许的漏模光子带还没有被研究过。了解传播的泄漏模式和非线性增益的影响，载波诱导的折射率变化，和热透镜，激光阈值以上，将导致下一代光源的发展有价值的知识基础。他提出了一个紧密结合的实验和理论计划来研究这些结构的独特性质，并利用这些性质来开发新型二极管激光源。这些结构具有很高的潜力，实现紧凑的单片表面发射源具有高的空间相干性。与传统的VCSEL阵列不同，所提出的器件在低折射率晶格位置具有增益，因此依赖于通过漏波的长距离（相干）耦合。基于MOCVD再生长工艺，反波导的内置折射率阶跃可以相当大（Dn = 0.10 - 0.20），使得结构对在激光阈值以上发生的波导扰动不太敏感。提出了基于二维有源光子晶格的新型器件结构，用于实现空间相干面发射光源：1。 横向谐振、大面积空间相干2-D锁相阵列：涉及矩形以及三角形晶格配置的大面积锁相阵列的反制导VCSEL器件依赖于径向谐振漏波耦合，这反过来确保了整个阵列结构上的均匀强度分布，从而确保了在阈值以上的高驱动水平的相干操作。 辐射扇出垂直腔半导体光放大器：漏波耦合垂直腔面发射放大器（VCSOA）阵列不仅具有提供高放大输出功率的潜力，而且还可以作为非线性相互作用（如四波混频）的大体积增益介质。3. 基于低折射率缺陷的激光器：提出了依赖于径向反谐振器件的“晶格缺陷”VCSEL器件，其允许从比常规VCSEL大一个数量级的发射区域进行单模操作。所提出的器件有可能作为高相干功率（100 mW）的圆光束单片光源，用于光纤通信系统中的发射机（l=1.3-1.55mm）或放大器泵浦源（l=0.98mm）。

In this work the PI will exploit the mode selectivity properties of two-dimensional arrays of closely spaced leaky-mode VCSELs to achieve spatially-coherent light sources. Two-dimensional arrays of closely spaced antiguided VCSELs offer a unique platform to study the optical modal properties of an active photonic lattice. He proposes the first comprehensive above-threshold study of the leaky-modes supported by such photonic lattice structures. The allowed leaky-mode photonic bands of 2-D active photonic lattices have not been studied to date. An understanding of the propagating leaky-modes and the influence of nonlinear gain, carrier-induced-index variations, and thermal lensing, above laser threshold will result in a valuable knowledge base for the development of next generation optical sources. He proposes a closely coupled experimental and theoretical program to study the unique properties of these structures and exploit these properties for the development of novel diode laser sources. These structures have high potential for the realization of compact monolithic surface emitting sources with high-spatial coherence. Unlike conventional VCSEL arrays, the proposed devices have gain placed in the low-index lattice sites, thus relying on long-range (coherent) coupling via leaky waves. Based on an MOCVD regrowth process, the built-in refractive index step of the antiguides can be quite large (Dn = 0.10 - 0.20), making the structure less sensitive to waveguide pertubations which occur above laser threshold. Novel device structures based on 2-D active photonic lattices are proposed for achieving spatially-coherent surface emitting sources:1. Laterally resonant, large-area spatially-coherent 2-D phase-locked arrays: Antiguided VCSEL devices involving large-area phase-locked arrays of rectangular- as well as of triangular-lattice configuration relying on radially resonant leaky-wave coupling, which in turn insures uniform intensity profile across the entire array structure, and thus coherent operation to high drive levels above threshold.2. Radiation fanout vertical cavity semiconductor optical amplifiers: Arrays of leaky-wave-coupled vertical-cavity surface-emitting amplifiers (VCSOA) hold potential not only for providing high amplified output powers but also act as a large-volume gain media for nonlinear interactions such as four-wave mixing. 3. Low-index defect based lasers: lattice-defect" VCSEL devices are proposed relying on radially antiresonant devices, which allow single-mode operation from emitting areas an order of magnitude larger than conventional VCSELs. The proposed devices have potential as high-coherent-power ( 100 mW), circular-beam monolithic sources for use as transmitters (l=1.3-1.55mm) or amplifier pump sources (l=0.98mm) in fiber-optical communication systems.