Radio frequency transmitter based on a laser frequency comb
Radio frequency transmitter based on a laser frequency comb
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DOI：
10.1073/pnas.1903534116
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发表时间：
2019-04
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影响因子：
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通讯作者：
M. Piccardo;Michele Tamagnone;B. Schwarz;P. Chevalier;N. Rubin;Yongrui Wang;Christine A. Wang;M. Connors;Daniel McNulty;A. Belyanin;F. Capasso
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文献类型：
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作者：
M. Piccardo;Michele Tamagnone;B. Schwarz;P. Chevalier;N. Rubin;Yongrui Wang;Christine A. Wang;M. Connors;Daniel McNulty;A. Belyanin;F. Capasso
半导体激光器是紧凑的相干光源。当以光频梳方式工作时，它们可以产生由等间距的离散频率线组成的光谱。大多数频率梳应用，如光谱学和计量学，直接使用这些激光器的光输出。在微波光子学应用中，频率梳输出被发送到快速光电探测器并用于产生微波。在这里，我们建议将激光器，探测器和天线集成在同一设备中。我们表明，除了产生微波，一个适当设计的激光器可以无线发射微波，并调制它们与包含信息的信号。这项工作打开了一扇大门，一种类型的混合电子光子器件。自赫兹时代以来，无线电发射机已经从发射约50 MHz的基本电路发展到以千兆赫无线电频段运行的现代无处不在的Wi-Fi设备。随着无线数据业务持续增加，需要能够进行高频操作以进行高速数据传输的新通信技术。在这里，我们给出了一个紧凑的射频发射机的概念的基础上的半导体激光器频率梳。在这种激光器中，在腔内振荡的相干模式之间的拍频产生一个射频电流，耦合到设备的电极。我们表明，重新设计的激光器的顶部接触允许一个利用内部振荡电流驱动偶极子天线，辐射到自由空间。此外，激光电流的直接调制允许在辐射的射频载波中编码信号。在相反的方向上工作，天线可以接收外部射频信号，将其耦合到有源区，并注入锁定激光器。这些结果为光频梳的应用和功能铺平了道路，例如无线电通信和与参考源的无线同步。
Significance Semiconductor lasers are compact sources of coherent light. When operating in an optical frequency comb regime, they can generate a spectrum consisting of discrete frequency lines that are equally spaced. Most frequency comb applications, such as spectroscopy and metrology, directly use the optical output of these lasers. In microwave photonics applications, the frequency comb output is sent to a fast photodetector and used to produce microwaves. Here, we propose to integrate laser, detector, and antenna in the same device. We show that, in addition to generating microwaves, a properly designed laser can emit microwaves wirelessly and modulate them with a signal containing information. This work opens the door to a type of hybrid electronic–photonic devices. Since the days of Hertz, radio transmitters have evolved from rudimentary circuits emitting around 50 MHz to modern ubiquitous Wi-Fi devices operating at gigahertz radio bands. As wireless data traffic continues to increase, there is a need for new communication technologies capable of high-frequency operation for high-speed data transfer. Here, we give a proof of concept of a compact radio frequency transmitter based on a semiconductor laser frequency comb. In this laser, the beating among the coherent modes oscillating inside the cavity generates a radio frequency current, which couples to the electrodes of the device. We show that redesigning the top contact of the laser allows one to exploit the internal oscillatory current to drive a dipole antenna, which radiates into free space. In addition, direct modulation of the laser current permits encoding a signal in the radiated radio frequency carrier. Working in the opposite direction, the antenna can receive an external radio frequency signal, couple it to the active region, and injection lock the laser. These results pave the way for applications and functionality in optical frequency combs, such as wireless radio communication and wireless synchronization to a reference source.