Hollow-glass, infrared bundles for coherent imaging

9874115哈林顿拟议工作的总体目标是开发制造宽带红外成像所需的低损耗、相干像束所需的空芯波导技术。要采取的方法是制造中空玻璃相干光束，然后将其涂覆用于宽带红外传输。图像束将使用芯棒缠绕和浸出束技术来制造。使用中空氧化物玻璃管形成束的优点是，这里可以使用用于实芯玻璃纤维的传统相干束方法。一旦制成了连贯的空心导向束，玻璃管的内壁将使用罗格斯大学开发的两种技术进行涂层。第一种是液相化学，第二种是化学气相沉积(CVD)。这些方法在制作损耗低至0.1分贝/米、长度高达13米的单波导方面已被证明是非常成功的。该计划中的挑战是将目前用来覆盖孔径小至250微米的单个中空波导的技术扩展到大约50微米口径的波导，这将构成红外像束。这项研究的意义在于，通过沉积多层介质涂层，中空玻璃波导的损耗有望降低10倍或更多。用于2~m以外成像的高效相干红外光束的开发将标志着首次制造出如此高分辨率的宽带光束，相信这项技术将对用于识别和过程控制的热成像系统产生重大影响。如果我们成功地将空心导轨的损耗降低到电流损耗的十分之一，我们将不仅拥有一种非常适合热成像的光纤，而且还将拥有一种在为外科和其他医疗应用提供激光功率方面具有巨大潜力的波导。此外，我们的中空束可以用于发射模式以及接收模式。也就是说，可以将激光能量转换为局部加热，然后通过相同的光纤束询问产生的热能。最后，应该有可能通过相同的中空导向束制造涉及热成像、电力传输和化学传感的终极智能光纤。*

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.***