School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
Department of Electro-Optics and Photonics, University of Dayton, 300 College Park, Dayton, Ohio 45469, USA.
Sci Rep. 2016 Dec 23;6:39626. doi: 10.1038/srep39626.
Highly efficient fan-out elements are crucial in coherent beam combining architectures especially in coupled laser resonators where the beam passes through the fan-out element twice per round trip. Although the theoretical efficiency is usually less than 86%, the Dammann gratings are ubiquitously utilized in a variety of types of coherent beam combining systems due to the facile design and fabrication. In the current paper, we experimentally demonstrate a highly efficient fan-out polarization grating. It is the first time to our knowledge that all the three space-variant parameters of a polarization grating are simultaneously optimized to achieve the function of multi-beam splitting. Besides the high fan-out efficiency, the ability to control the polarization states of individual split beams is another advantage of this polarization grating. The novel polarization grating is promising to find applications in laser beam combining systems.
高效的光束分束元件在相干光束组合架构中至关重要，特别是在耦合激光谐振器中，光束每经过一个往返周期就要通过分束元件两次。尽管理论效率通常低于 86%，但由于设计和制造简单，达曼光栅在各种类型的相干光束组合系统中被广泛应用。在目前的论文中，我们实验验证了一种高效的光束分束偏振光栅。据我们所知，这是首次同时优化偏振光栅的三个空间变化参数以实现多光束分光功能。除了高效率的分束，该偏振光栅还可以控制各个分束光束的偏振态，这是其另一个优势。这种新型偏振光栅有望在激光光束组合系统中得到应用。
