Hollow-glass, infrared bundles for coherent imaging

9874115 Harrington提出的工作的总体目标是开发必要的中空波导技术，以制造低损耗，相干的宽带红外成像的图像束。所采取的方法是制造中空玻璃，相干束，然后可以涂上宽带红外传输。图像束将使用芯轴缠绕和沥滤束技术制造。使用中空氧化物玻璃管形成束的优点在于，这里可以使用用于实芯玻璃纤维的常规相干成束方法。一旦制造出连贯的中空导束，玻璃管的内壁将使用罗格斯大学开发的两种技术进行涂覆。第一种是液相化学，第二种是化学气相沉积（CVD）。这些方法已被证明在制作损耗低至0.1 dB/m和长度达13 m的单波导方面非常成功。该计划的挑战是将目前用于涂覆孔径小至250 μ m的单个中空波导的技术扩展到构成红外图像束的孔径约为50 μ m的波导，该研究的意义在于通过多层介质涂层的沉积，预期中空玻璃波导的损耗将降低10倍或更多。一个有效的，相干的红外光束超过2米的成像的发展将标志着第一次，这样一个高分辨率，宽带束已经制造，它被认为，这项技术将有一个重大影响的热成像系统用于识别和过程控制。如果我们成功地将中空波导的损耗降低到电流损耗的十倍，我们不仅将拥有非常适合热成像的光纤，而且还将拥有在外科手术和其他医疗应用中提供激光功率的巨大潜力的波导。此外，我们的空心束可以用于发射模式以及接收模式。也就是说，可以传输激光能量用于局部加热，然后经由相同的光纤束询问所产生的热能。最后，应该可以通过相同的中空导束制造最终的智能光纤，包括热成像，功率传输和化学传感。

9874115HarringtonThe overall objective of the proposed work is to develop the hollow waveguide technology necessary to fabricate low-loss, coherent image bundles for broadband infrared imaging. The approach to be taken is to fabricate hollow-glass, coherent bundles which then can be coated for broadband infrared transmission. The image bundles will be fabricated using both mandrel wrap and leach bundle technologies. The advantage of using hollow oxide glass tubing to form the bundles is that conventional coherent bundling methods used for solid-core glass fibers can be used here. Once the coherent hollow guide bundles have been made, the inside walls of the glass tubing will be coated using two technologies developed at Rutgers University. The first is liquid-phase chemistry and the second is chemical vapor deposition (CVD). These methods have proven very successful in making single waveguides with losses as low as 0.1 dB/m and lengths up to 13 m. The challenge in this program is to extend the current technology used to coat single hollow guides with bore sizes as small as 250 um to the approximately 5O-~m-bore size guides which will make up the IR image bundle.The significance of this research lies in the anticipated reduction in loss for hollow glass guides by a factor of 10 or more through the deposition of multilayer dielectric coatings. The development of an efficient, coherent IR bundle for imaging beyond 2 ~m would mark the first time that such a high resolution, broadband bundle has been fabricated and, it is believed, this technology will have a major impact on thermal imaging systems used for recognition and process control. If we are successful in reducing the loss of the hollow guides by a factor of ten over current losses we will not only have a fiber well suited for thermal imaging but also a waveguide with significant potential in delivering laser power for surgical and other medical applications. In addition, our hollow bundle could be used in a transmit mode as well as in the receive mode. That is, it is possible to transniit laser energy for local heating and then to interrogate the resulting thermal energy via the same fiber bundle. Finally, it should be possible to make the ultimate smart fiber optic involving thermal imaging, power delivery, and chemical sensing all via the same hollow guide bundle.***