Optical Phased Laser Arrays and Their Functionality

半导体激光器在我们日常生活的许多方面，以及我们国家的经济和安全方面有着越来越重要的影响。互联网依靠微小的激光器将来自我们智能手机和电脑的信息通过光纤传输到世界各地，而低成本制造汽车、飞机和消费品则需要激光进行精确切割和焊接。为了继续扩大和提高互联网的性能，或进一步降低制造成本，改进半导体激光器的性能是必要的。进一步改进的传统方法并不明显，因此对于高速数据传输以及高功率激光光输出，激光制造业在技术领域已经接近性能极限，习惯于每隔几年或更少的时间增加一个数量级。因此，需要新的思想和范式来突破这些性能障碍。该项目的研究旨在开发新的半导体激光芯片，以解决更快的光传输数据以及增加激光输出功率的问题。通过光纤以更少的电力和更快的速度分发更大量的数字数据的能力，将是数据中心的关键推动因素，这在最近的一份美国国家工程院报告中被确定为美国的关键挑战。高功率激光器也将导致更可靠的制造工艺和更低的成本生产，或更紧凑的激光源显示应用。最后，高亮度激光器的发展还可以使新一代定向能武器成为可能，以增强美国的安全。该研究项目结合了半导体激光器的设计、仿真、制造和表征，以挑战和教育电气工程专业本科生和研究生的不同群体，包括课堂和实验室经验。本研究的方法是在单个半导体芯片内开发多个激光器，以相干耦合的方式共同作用。具体来说，阵列中每个激光器的光波长和相位将以这样一种方式控制，即所有激光束相干地组合在一起。激光器的相干组合并不简单地导致光束的增加，但事实上，整体输出光强度随着阵列中激光器数量的平方而增加。此外，控制所有光束相干组合的阵列中每个激光器的相位可以显著提高数字传输应用的调制速率（使激光变亮和变暗的速率）。控制阵列中每个激光元件的光波长和相位的关键是使每个激光二极管独立地电接触。本研究的智力价值源于对多个量子力学光振荡器的控制和操纵。在本研究项目中使用的制造方法与目前用于制造单个半导体激光器的方法相同，因此可以转移到美国的激光制造行业。此外，也许最重要的是，参与这项研究的学生将为未来在美国光子学行业的科学和工程职业做好准备。

Title: Coupling Multiple Semiconductor Lasers in a Single Chip for Applications of Fast Optical Data Transmission or High Power OperationSemiconductor lasers have an increasingly significant impact on many aspects of our daily lives, as well as the economy and security of our nation. The internet relies upon tiny lasers to transmit information originating from our smart phones and computers through optical fiber to destinations around the world, while the low cost manufacture automobiles, planes, and consumer goods require lasers for precision cutting and welding. To continue the expansion and improve the performance of the internet, or to further reduce manufacturing costs, improved performance of the properties of semiconductor lasers are necessary. Conventional approaches for further improvements are not obvious, whereby for both high speed data transmission as well as high power laser light output the laser manufacturing industry are near the limits of performance, in technology areas that are accustomed to an order of magnitude increase every few years or less. Therefore new ideas and paradigms are needed to break through these performance barriers. The research of this project seeks to develop new semiconductor laser chips that will address faster optical transmission of data as well as increased laser output power. The ability to distribute greater amounts of digital data over optical fiber with orders of magnitude less electricity and at faster rates, would be a key enabler for data centers, which has been identified in a recent National Academy of Engineering report as a critical U.S. challenge. High power lasers will also lead to more reliable manufacturing processes and lower cost production, or more compact laser sources for display applications. Finally, the development of high brightness lasers could also enable a new generation of directed energy weapons for enhanced U.S. security. This research program incorporates design, simulation, fabrication, and characterization of semiconductor lasers to challenge and educate a diverse group of undergraduate and graduate students in electrical engineering in both classroom and laboratory experiences.The approach of this research is to develop multiple lasers within a single semiconductor chip to act together in a coherently coupled manner. Specifically, the light wavelength and phase of each of the lasers in the array will be controlled in such a manner that all of the laser beams are combined together coherently. The coherent combination of the lasers does not simply result in the addition of the beams, but in fact the overall output light intensity increases as the square of the number of lasers in the array. Moreover, the control of the phase of each of the lasers in an array with all of the beams coherently combined can produce a significant increase of the modulation rate (the rate of turning the laser light brighter and dimmer) for digital transmission applications. The key aspect to control the light wavelength and phase of each laser element of the array is to independently electrically contact each laser diode. The intellectual merit of this research originates from the control and manipulation of multiple quantum mechanical optical oscillators. The fabrication approaches that are used in this research project are the same as those presently employed to manufacture individual semiconductor lasers, and thus can be transferred to the laser manufacturing industry in the United States. Furthermore and perhaps most importantly, the students involved in this research will be prepared for future scientific and engineering careers in the U. S. photonics industry.