High-Power, Phase-Locked Single-Frequency Arrays of Diode Lasers

9522035 Botez反制导二极管激光器的锁相阵列（所谓的ROW阵列）已经证明了1-1.5W的衍射极限功率，这是全单片振荡器的最高相干功率。 然而，这些器件没有单频输出，这妨碍了它们在许多应用中的使用。 此外，所有目前的时间，它们的元素的数量被限制为20，这反过来又限制了相干功率的量。 在此建议：1）开发具有分布式反馈（DFB）内置结构的ROW阵列，用于空间模式控制;以及2）实施新概念，将阵列元件的数量从20个增加到40-80个，同时保持单一空间模式。 对于row-DFB阵列，建议的材料系统是InGaAs/InGaP/GaAs，一种无Al结构，可确保无缺陷的再生长，高效率，可靠性和低线宽增强因子。 因此，20元件的ROW-DFB器件有望提供单频，衍射限制光束操作到1 W，线宽= 50 kHz。 为了增加模间鉴别，从而允许具有多于20个元件的器件的单空间模式阵列操作，提出了两个新概念：1）通过来自掩埋衍射光栅的选择性反馈的阵列（横向）模式选择，以及2）横向限制反射器（LRR）。 这两个概念都依赖于ROW-DFB器件的单频特性。 高阶阵列模式的歧视优先反馈。 这些器件将通过使用金属有机化学气相沉积进行晶体生长;电子束和/或X射线光刻和化学蚀刻用于光栅制造;以及电子束光刻和优先蚀刻用于阵列图案生成。 理论分析和设计将采用过时的阵列，光束传播方法，和块功能形式主义的1-D和2-D有限周期性结构的矩阵公式。 行-DFB器件实际上是2-D光子晶格。 他们将为这种激光器的工作原理提供新的线索，并将激发人们对基于光子晶格的其他类型设备的兴趣。 瓦级、单频、衍射极限光束稳定光源的实现将对并行光信号处理、通过谐波转换产生蓝光、产生用于环境监测的中红外相干光以及自由空间光通信产生重大影响。 该研究计划与美国各大公司和实验室的光电研究和开发小组密切合作，包括AT T贝尔实验室，Uniphase，New Focus，TRW和大卫萨尔诺夫研究中心。 该计划的一个主要特点是在光电器件研究的这一重要领域培养研究生和本科生。 ***

9522035 Botez Phase-locked arrays of antiguided diode lasers (so called ROW arrays) have demonstrated 1-1.5W of diffraction-limited power, the highest coherent powers for all-monolithic oscillators. However, the devices do not have a single-frequency output, which prevents their use in many applications. Furthermore, all the present time, their number of elements is limited to 20 ,which in turn limits the amount of coherent power. It is proposed here to: 1) develop ROW arrays with a distributed feedback (DFB) built-in structure for longitudinal-mode control; and 2) implement novel concepts for increasing the number of array elements from 20 to 40-80, while maintaining a single spatial mode. For ROW-DFB arrays the proposed material system is InGaAs/InGaP/GaAs, an A1-free structure that assures defect-free regrowths, high efficiency, reliability, and low linewidth enhancement factor. As a result 20-element ROW-DFB devices are expected to provide single-frequency, diffraction-limited-beam operation to 1W with linewidths of = 50kHz. In order to increase the intermodel discrimination, and thus allow for single-spatial mode array operation of devices with more than 20 elements, two novel concepts are proposed: 1) array-(lateral)-mode selection via selective feedback from a buried diffraction grating, and 2) laterally restricted reflector (LRR). Both concepts rely on the single-frequency nature of ROW-DFB devices. High-order array modes are discriminated against by preferential feedback. The devices will be made by using metalorganic chemical vapor deposition for crystal growth; e-beam and/or X-ray lithography and chemical etching for grating fabrications; and e-beam lithography and preferential etching for array pattern generation. Theoretical analysis and design will be performed employing the matrix formulation for antiquated arrays, the beam propagation method, and the Block-function formalism for 1-D and 2-D finite periodic structures. ROW-DFB devices are in effect 2-D pho tonic lattices. Their will shed new light on how such lasers work, and will spur interest in other classes of devices based on photonic lattices. The realization of watt-range, single-frequency, diffraction-limited-beam stable sources will have significant impact on parallel optical-signal processing, the generation of blue light via harmonic conversion, the generation of mid-IR coherent light for environmental monitoring, and free-space optical communications. This research program is strongly coupled to collaborative with optoelectronic research and development groups at various major US companies and laboratories, including AT&T Bell Labs, Uniphase, New Focus, TRW, and David Sarnoff Research Center. A key feature of the program is the training of graduate and undergraduate students in this significant area of optoelectronic device research. ***