Polymer based electro-optic (EO) modulators have the potential to provide low cost and lightweight alternative for antenna remoting and RF links because of their wide bandwidth (100 GHz) and low drive voltage (V/sub /spl pi//1 V) capabilities. Low noise figure and low power consumption systems require low insertion loss modulators. There are two major causes of loss in EO modulators: waveguide propagation loss (typically 1 dB/cm), and fiber-to-waveguide coupling loss. In this paper we investigate methods to minimize fiber-to-waveguide coupling loss which is mainly due to mode size mismatch. Pigtails using standard single mode fiber produce coupling loss on the order of 3 to 5 dB/connection. In order to improve mode size matching yet maintain low drive voltage, we incorporate waveguide and fibers tapers. Experimental results indicate improvement of up to 3 dB/connection (6 dB/device) using waveguide tapers, and up to 2 dB/connection (4 dB/device) using fiber tapers.
展开▼
机译：基于聚合物的电光（EO）调制器具有可提供天线远程处理和RF链路的低成本和轻量级替代方案，因为它们宽带宽（<100 GHz）和低驱动电压（V / SEC / SPL PI //> 1 v）能力。低噪声系数和低功耗系统需要低插入损耗调制器。 EO调制器中存在两种主要原因：波导传播损耗（通常为1dB / cm）和光纤到波导耦合损耗。在本文中，我们研究了最小化光纤到波导耦合损耗的方法，该耦合损耗主要是由于模式尺寸不匹配。使用标准单模光纤的尾纤产生约3至5 dB /连接的耦合损耗。为了提高模式尺寸匹配但保持低驱动电压，我们将波导和纤维锥形塑钩。实验结果表明，使用波导锥度的提高高达3 dB /连接（6 dB /设备），使用光纤锥形最多2个DB /连接（4 dB /设备）。
展开▼
