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。密集排列的VCSEL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。他提出了第一个对这种光子晶格结构支持的漏模进行全面的高于阈值的研究。二维有源光子晶格允许的漏模光子带到目前为止还没有被研究过。了解激光阈值以上的传输漏模式以及非线性增益、载流子诱导折射率变化和热透镜的影响，将为下一代光源的发展提供有价值的知识基础。他提出了一个紧密耦合的实验和理论计划，以研究这些结构的独特性质，并将这些性质用于开发新型半导体激光光源。这些结构在实现高空间相干性的紧凑型整体式表面发射源方面具有很高的潜力。与传统的VCSEL阵列不同，该器件的增益位于低折射率晶格点，因此依赖于通过漏波的长程(相干)耦合。基于MOCVD再生长过程，反波导的固有折射率步长可以很大(Dn=0.10-0.20)，使得结构对高于激光阈值的波导扰动不那么敏感。提出了一种基于二维有源光子晶格的新型器件结构，用于实现空间相干表面发射源：1.横向共振的大面积空间相干二维锁相阵列：采用基于径向共振漏波耦合的大面积矩形和三角形晶格锁相阵列的反引导VCSEL器件，进而确保整个阵列结构上均匀的强度分布，从而对高于阈值的高驱动电平进行相干操作。辐射扇出垂直腔面发射放大器：漏波耦合垂直腔面发射放大器阵列不仅具有提供高放大输出功率的潜力，还可以作为四波混频等非线性作用的大体积增益介质。3.基于低折射率缺陷的激光器：晶格缺陷“VCSEL器件是一种基于径向抗谐振器件的VCSEL器件，它允许从发射区域获得比常规VCSEL大一个数量级的单模运转，在光纤通信系统中可用作高相干功率(100 MW)、圆形光束单片光源(L=1.3-1.55 mm)或放大泵浦光源(L=0.98 mm)。

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.