提出了一种基于达曼光栅的动态光耦合器,通过控制装置中达曼光栅位移参量,可实现入射光束的分束或合束以及两者之间的动态转换。适当选择达曼光栅类型可实现任意N×M的动态光耦合。实验中以1550 nm光波长为例,对1×8达曼动态光耦合器进行测量,测得其实现光开关功能时插入损耗为0.43 dB,实现光分束功能时均匀性达到0.03,单路插入损耗均值为10.5 dB。该实验装置易于调节、体积小、能耗低,且关键元件达曼光栅制作工艺成熟,易于批量化生产。特别是在实现中大规模光交换阵列时,该方案就具有更明显的优越性,有实用意义。

A novel dynamic optical coupler is presented by employing a specially designed Dammann grating. By controlling the shift parameter of Dammann grating, this device can easily realize the function of either a beam splitter or a combiner and transformation between both of them. An arbitrary N×M dynamic optical coupling can be achieved by choosing an appropriate Dammann grating. In the experiment a high performance 1×8 dynamic coupler achieves good uniformity of 0.03, insertion loss of around 10.5 dB for each channel as a splitter and a low insertion loss of 0.43 dB as a switch at the wavelength of 1550 nm. This device has the advantages of easy adjustment, compact size and low loss. Moreover, Dammann grating used in the experiment can be easily mass-fabricated by binary optical technology. In addition, this system is a preferable approach in the integral packaging. This device has the unique diffractive advantages of Dammann-grating-incorporated system for dynamic optical coupling of a large fiber array. Note that this method is generally applicable and should be interesting for practical use.