Frequency conversion with nonlinear graphene photodetectors
Frequency conversion with nonlinear graphene photodetectors
复制标题
使用非线性石墨烯光电探测器进行频率转换
DOI：
10.1039/c6nr08964j
复制
发表时间：
2017-03-28
期刊：
影响因子：
6.7
通讯作者：
Chen, Hongda
中科院分区：
文献类型：
--
作者：
Cheng, Chuantong;Huang, Beiju;Chen, Hongda
利用非线性电子元件进行频率变换是各种通信应用中常用的信号处理方法，但由于传统材料载流子迁移率的限制，其工作带宽已成为瓶颈。同时，光纤通信由于其优良的信号传输特性，在通信服务中发挥着重要的作用。然而，在通过传统的电子器件进行频率转换之前，必须用光电探测器将传输的光信号转换成电信号，这使得这种转换系统非常复杂和昂贵。因此，开发一种能够同时实现光检测和频率转换功能的紧凑型器件是非常重要和有意义的。在这里，我们提出了一种新的频率转换概念，并展示了一种基于非线性石墨烯光电探测器的频率转换器，它直接从光信号进行频率转换。利用这一新概念，从2 GHz的强度调制光信号中获得了4 GHz的倍频信号。此外，利用10 MHz强度调制光信号和3 GHz强度调制光信号，实现了3+/-0.01 GHz的频率上转换。特别是利用2 GHz强度调制光信号和2.1 GHz强度调制光信号成功地实现了100 MHz的频率下变频。考虑到石墨烯材料的宽带光吸收、强饱和吸收、高载流子迁移率和短的光生载流子寿命，石墨烯光电探测器有可能实现毫米波频段的频率转换，这将为下一代通信系统在微波光子学领域开辟广阔的前景。
Frequency conversion with nonlinear electronic components, a common approach for signal processing required in various communication applications, has found its operation bandwidth bottleneck due to the limited carrier mobility of the traditional materials. Meanwhile, fiber-optics communications are playing a significant role in communication services due to their excellent signal transmission properties. However, the transmitted optical signals had to be converted to electrical signals with photodetectors before frequency conversion was performed through conventional electronic devices, which make this conversion system very complex and costly. Hence, to develop a compact device that can achieve the photodetection and frequency conversion functions simultaneously is critical and significative. Here, we have proposed a novel concept for frequency conversion and demonstrated a nonlinear graphene photodetector based frequency converter that performs frequency conversion from optical signals directly. With this new concept, a frequency doubling signal at 4 GHz was obtained from a 2 GHz intensity-modulated optical signal. Moreover, using a 10 MHz intensity-modulated optical signal and another 3 GHz intensity-modulated optical signal, we show the frequency up-conversion to 3 +/- 0.01 GHz. In particular, the frequency down-conversion to 100 MHz was achieved successfully by using a 2 GHz intensity-modulated optical signal and another 2.1 GHz intensity-modulated optical signal. Considering the broadband optical absorption, strong saturable absorption, high carrier mobility, and short photogenerated carrier lifetime of the graphene material, graphene photodetectors have the potential to achieve the frequency conversion of millimeter-wave band, which will open promising prospects in the domain of microwave photonics for next-gen communication systems.