Improvement of Contrast Ratio in QPSK Optical Label Recognition with Passive Optical Waveguide Circuit
Improvement of Contrast Ratio in QPSK Optical Label Recognition with Passive Optical Waveguide Circuit
复制标题
无源光波导电路QPSK光标签识别对比度的提高
DOI：
10.1117/1.oe.55.5.057104
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发表时间：
2016
影响因子：
1.3
通讯作者：
Nobuo Goto and Shin-ichiro Yanagiya
中科院分区：
文献类型：
--
作者：
Hiroki Kishikawa;Yoshihiro Makimoto;Kensuke Inoshita;Sanae Igarashi;Nobuo Goto and Shin-ichiro Yanagiya
在光标签路由网络中，光标签识别是关键功能之一。我们已经提出了波导型光路识别的四相移键控（QPSK）的形式编码的光学标签。该电路的基本器件由一个3 dB定向耦合器、两个Y分支和一个非对称X结耦合器组成。在我们以前报道的论文中，我们采用了每个编码脉冲和参考脉冲之间的光波完全干涉的方案。据报道，对于识别16、64和256个QPSK标签的两级、三级和四级电路，目标输出端口处的输出与其他端口处的输出的对比度分别降低到1.6、1.28和1.13。我们找到最佳电路，提高对比度为1.8，1.6，和1.47 16，64，和256标签，分别。利用光束传播法对改进电路的识别效果进行了数值验证。通过数值模拟，也阐明了所提出的电路的噪声容限。从光功率的有效利用和噪声容限的角度来看，改进的电路是最佳的。
In photonic label routing networks, recognition of optical labels is one of the key functions. We have proposed waveguide-type optical circuits for recognition of optical labels encoded in quadriphase-shift-keying (QPSK) form. A basic device for the circuits consists of a 3-dB directional coupler, two Y-branches, and an asymmetric X-junction coupler. We employed a scheme of complete interference of optical waves between each coded pulse and a reference pulse in our previously reported paper. The contrast ratio of the output at the destination output port to the outputs at the other ports was reported to decrease to 1.6, 1.28, and 1.13 for two-, three-, and four-stage circuits for recognition of 16, 64, and 256 QPSK labels, respectively. We find optimum circuits with improved contrast ratio of 1.8, 1.6, and 1.47 for 16, 64, and 256 labels, respectively. The recognition operation with the improved circuits is numerically confirmed using the beam propagation method. Noise tolerance of the proposed circuits is also clarified by numerical simulation. The improved circuits are optimum from the viewpoint of efficient use of optical power and noise tolerance.