A Novel Light Routing Device with Phase Encoding using Liquid Crystal Spatial Light Modulator

一种采用液晶空间光调制器的相位编码新型光路由装置

基本信息

批准号：
09650387
负责人：
KANNARI Fumihiko
金额：
$ 1.98万
依托单位：
Department of Electrical Engineering, Faculty of Science and Technology, Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

A novel space variant optical interconnection, where the spatial routing pattern among nodes is variable only by changing the phase encoding pattern embedded on a spatial light modulator (SLM), is proposed and experimentally examined its basic performance for one-dimensional routing patterns. The spatial phase profile of a coherent light is shaped with a segmented liquid crystal SLM so that the far-field pattern matches to a desired routing pattern. At the same time, the laser beam is encoded with a M-series code and converted to a quasi noise spatial pattern. Various routing patterns encoded with different M-series are multiplexed and send in space. At a receiver, only a desired routing pattern can be selected with an identical M-series phase mask. The rest of multiplexed signals remain as noise and eliminated by some threshold detectors. We obtained following conclusions through theoretical and experimental studies.(1) Assuming a 128x128 segmented SLM at 16 gray levels, one can multiplex more than 100 routing patterns using length-127 M-series phase codes.(2) Proof-of-concept experiments was conducted with a 128 one-dimensional SLM and a HeNe laser. Doubly encoded spatial routing pattern embedded on the SLM was successfully decoded with another SLM phase mask. The signal-to-loss ratio were evaluated for different M-series code lengths.(3) We demonstrated that a spatial pattern encoded for the spectral phase of an incoherent light can be sent through a fiber and recovered by forming a spectral holography. This time-to-space conversion scheme can open up new optical interconnections and communications.(4) In order to use spectral holography technologies in fiber delivered interconnections and communications, we demonstrated holography at 1.3mm wavelength. The hologram was first written by a SHG of 1.3mm laser and then read by the fundamental beam.

提出了一种新颖的空间变体光互连，其中节点之间的空间路由模式仅通过改变嵌入在空间光调制器（SLM）上的相位编码模式来改变，并通过实验检验了其一维路由模式的基本性能。相干光的空间相位轮廓通过分段液晶 SLM 进行整形，以便远场图案与所需的路由图案相匹配。同时，激光束用M系列代码进行编码，并转换为准噪声空间图案。用不同M系列编码的各种路由模式被复用并在空间中发送。在接收器处，只能使用相同的 M 系列相位掩模来选择所需的路由模式。其余的多路复用信号仍然作为噪声并被一些阈值检测器消除。通过理论和实验研究，我们得到了以下结论。(1)假设16个灰度级的128x128分段SLM，可以使用长度为127的M系列相位码复用超过100个路由模式。(2)概念验证实验使用 128 一维 SLM 和 HeNe 激光器进行。嵌入在 SLM 上的双重编码空间路由模式可以使用另一个 SLM 相位掩模成功解码。针对不同的 M 系列码长评估了信损比。(3) 我们证明，为非相干光的光谱相位编码的空间图案可以通过光纤发送，并通过形成光谱全息术来恢复。这种时空转换方案可以开辟新的光互连和通信。(4)为了在光纤传输互连和通信中使用光谱全息技术，我们演示了1.3mm波长的全息技术。全息图首先由 1.3mm 激光器的 SHG 写入，然后由基波光束读取。