Optical Phased Laser Arrays and Their Functionality

标题：在单个芯片上耦合多个半导体激光器用于快速光数据传输或高功率操作半导体激光器对我们日常生活的许多方面以及我们国家的经济和安全都产生了越来越重要的影响。互联网依靠微小的激光将来自我们的智能手机和计算机的信息通过光纤传输到世界各地的目的地，而低成本制造汽车、飞机和消费品需要激光进行精密切割和焊接。为了继续扩大和提高互联网的性能，或者为了进一步降低制造成本，提高半导体激光器的性能是必要的。用于进一步改进的传统方法并不明显，从而对于高速数据传输以及高功率激光输出，激光制造业在习惯于每隔几年或更少的数量级增长的技术领域中接近性能极限。因此，需要新的理念和范式来突破这些绩效障碍。该项目的研究旨在开发新的半导体激光芯片，以解决更快的数据光学传输以及增加激光输出功率。能够以更少的电力和更快的速度通过光纤传输更大量的数字数据，将是数据中心的关键推动因素，这在美国国家工程院最近的一份报告中被确定为美国面临的一项关键挑战。高功率激光还将带来更可靠的制造工艺和更低的成本生产，或者用于显示应用的更紧凑的激光光源。最后，高亮度激光的发展还可能使新一代定向能武器能够增强美国的安全。这项研究计划结合半导体激光器的设计、模拟、制造和表征，在课堂和实验室经验中挑战和教育不同的电气工程本科生和研究生群体。这项研究的方法是在单个半导体芯片中开发多个激光器，以一致耦合的方式一起工作。具体地说，阵列中每个激光器的光波长和相位将以这样的方式被控制，即所有的激光光束被相干地组合在一起。激光的相干组合并不是简单地导致光束的增加，事实上，总体输出光强度随着阵列中激光器数量的平方而增加。此外，对所有光束相干组合的阵列中每个激光器的相位的控制可以产生用于数字传输应用的调制率(将激光变得更亮和更暗的速率)的显著增加。控制阵列中每个激光元件的光波长和相位的关键方面是独立地电接触每个激光二极管。这项研究的智力价值源于对多量子力学光学振荡器的控制和操纵。这项研究项目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电子行业的科学和工程职业做准备。

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.