A study on design and fabrication of self-aligned optical microconnectors for 2-dimensional parallel circuits

我们提出了一种新型的自对准光学元件和单模光纤阵列的方案，该方案由一个阵列插入式微连接器组成。采用自对准技术，在平面微透镜衬底上制作了由刻蚀的单模透镜插孔和光纤插头组成的插入式微连接器。研究了非精确机械对准条件下的一些光耦合特性。在这项研究中，我们的目标是利用这种插入式微连接器阵列来实现多功能光学电路。因此，低损耗光纤连接器的实现、自对准连接评价方法的建立、光连接模块的设计和基础研究是本课题研究的目标。在633 nm波长处，连接损耗小于5db。此外，还发现引入透镜插孔和光纤插头的连接损耗很小。通过将平面微透镜假设为薄透镜，建立了光学自对准的评价方法。我们还估计了每个模块的损失。如果光纤与半导体激光二极管的连接没有角度和位置误差，则半导体激光器与平面微透镜之间的距离约为15um，对于1dB的公差，平面微透镜与光纤之间的距离约为150um。通过分析发现，不能忽略平面微透镜的球差的影响。研究发现，插入式微连接器是减小这种球差的合适结构。因此，它将成为先进的并行光纤通信中的简单光耦合器的关键技术。

We have proposed a novel scheme of self-aliging optical components and single mode fiber arrays, which is composed of an array put-in microconnectors. We fabricated a put-in microconnector consisting of an etched single mode lens jack and an fiber plug formed on a planar microlens substrate by a self-aligning technique. Some optical coupling characteristics without precise mechanical alignment were investigated. In this study, we aim at the realization of multifunction optical circuits using this put-in microconnector array. Therefore, the realization of low loss fiber connector, the establishment of evaluation method of self-aligning connects, the design and fundamental study of optical connect module are the objectives of this study.We tried to connect self-alignment between a single mode fiber and a planar microlens. The loss of connection was less than 5dB at the wavelength of 633nm. Besides, it was found that the connection loss by introducing of the lens-jack and fiber-plug is very small. We established the evaluation method of optical self-alignment by assuming a planar microlens to a thin lens. We also estimated the loss of each module. If the fiber is connected to the semiconductor laser diode without the error of connection angle and position, the distance between the semiconductor laser diode and the planar microlens is about 15mum, the distance between the planar microlens and the fiber is about 150mum for the tolerance of 1dB.It is found that we cannot omit the influence of spherical aberration of planar microlens, by this analysis. We found that the put-in micro connector is suitable structure for decreasing this spherical aberration. Thus, it will be a key technology for simple optical couplers for the advanced parallel optical fiber communications.