Fabrication and Characterization of Integrated Waveguide Laser Devices

我们的建议的总体目标是探索在单个磷酸盐玻璃波导中集成激光介质和光学写入的布拉格光栅以及非线性光学元件的全波导激光器件的制备和特性。非线性元件可以是波导器件的周期性极化(用于倍频)或均匀极化(用于电光调制器)。电信行业的快速增长导致了对新型光纤组件的密集研究和开发，如掺铒光纤放大器(EDFA)、光纤布拉格光栅和光纤激光器。作为电信应用的副产品，光纤现在也迅速进入其他工业应用，如医药和传感器技术。对于某些应用，波导结构可能优于光纤，因为其紧凑性以及能够在单个衬底上集成不同的光学组件，例如分路器、耦合器和激光放大器或信号源。如果能将现有的波导型激光技术与非线性光学元件集成在一起，使激光器和非线性光学功能集成在同一个波导中，将大大提高现有的波导型激光器技术。这种集成光学方法需要在波导中使用布拉格光栅来定义激光腔。玻璃中通常不存在的二阶光学非线性可以通过热极化过程引入。这里描述的研究涉及以下两个问题：1.通过在磷酸盐玻璃和波导中的光学写入过程来研究折射率变化和布拉格光栅的形成。这里的目标是通过掺杂对玻璃的敏化或者通过用高峰值功率激光器写入超短(100 Fs)脉冲来有效地在磷酸盐玻璃和光波导中写入布拉格光栅。研究了在这些玻璃中通过热极化形成二阶非线性。我们将进行实验，以确定磷酸盐玻璃中是否可以诱导二阶非线性，以及对哪些极化参数和玻璃成分进行优化。这项技术将导致新型集成光学器件的应用，特别是波分复用(WDM)和光计算，以及计量学、光谱学和遥感。此外，这些研究将有助于理解玻璃的光敏性和极化。由于其跨学科性质和与高科技产业的重大相关性，这项研究为研究生的教育和培训提供了独特的机会。

The overall objective of our proposal is to explore the fabrication and characterization of all-waveguide laser devices that integrate a lasing medium with optically written Bragg gratings and a nonlinear optical element in a single phosphate glass waveguide. The nonlinear element can either be a periodically poled (for frequency doubling) or uniformly poled segment (for an electro-optic modulator) of the waveguide device.The rapid growth of the telecommunications industry has led to intensive research and development of new fiber based components, such as Erbium doped fiber amplifiers (EDFAs), fiber Bragg gratings and fiber lasers. As a spin-off from telecom applications, fibers are now also rapidly finding their way into other industrial applications, such as medicine and sensor technology. For certain applications, waveguide structures may be preferred over fibers because of their compactness and the ability to integrate different optical components such as splitters, couplers and laser amplifiers or signal sources on a single substrate. Existing waveguide laser technology would be greatly enhanced if it could be integrated with a nonlinear optical, (2) , element in such a way that the laser and the nonlinear optical function were fabricated in the same waveguide. Such an integrated optics approach requires the use of Bragg gratings in the waveguide to define the laser cavity. Second-order optical nonlinearities, which do normally not occur in glasses, can be introduced through a thermal poling process.The research described here addresses the following two issues:1. A study of the formation of refractive index changes and Bragg gratings through an optical writing process in phosphate glasses and waveguides.Here the goal is to effectively write Bragg gratings in phosphate glasses and waveguides using sensitization of the glass through doping or by writing the grating with ultra-short (100 fs) pulses from a high peak-power laser.2. A study of the formation of a second-order nonlinearity through thermal poling in these glasses. Experiments will be carried out to determine whether a second-order nonlinearity can be induced in phosphate glasses and for which poling parameters and glass compositions it is optimized.This technology will lead to new integrated optical devices with applications in telecommunications - in particular WDM (wavelength division multiplexing)- and optical computing, as well as metrology, spectroscopy, and remote sensing.In addition, these studies will contribute to the understanding of photosensitivity and poling in glasses.Because of its multidisciplinary nature and great relevance for the high-tech industry, this research offers a unique opportunity for education and training of graduate students.