Opt Lett. 2018 Jun 1;43(11):2543-2546. doi: 10.1364/OL.43.002543.
In this Letter, we propose a monitoring and control system (MCS) for operating tunable optical delay lines (TODLs), regardless of their operation principle and implementation technology. The monitoring system resorts to two out-of-band pilot tones added to the input optical signal. The amplitude and phase difference between tones are retrieved to the control system, which calculates and applies the TODL control signals. The MCS was validated using a Mach-Zehnder delay interferometer-based TODL, implemented in three different silicon photonic integrated circuits (PICs). The three PICs resort to different kinds of phase shifters based on thermo-optic, carrier-injection, and carrier-depletion effects. The proposed MCS enabled tuning the delay within the entire range of the TODL in all tested PICs. The scalability of the MCS for large-scale photonic beamformers is discussed.
在这封信中，我们提出了一种用于操作可调谐光延迟线（TODL）的监控和控制系统（MCS），无论其操作原理和实现技术如何。监控系统采用两个带外导频信号添加到输入光信号中。 tones 的幅度和相位差被检索到控制系统，控制系统计算并应用 TODL 控制信号。使用基于马赫-曾德尔延迟干涉仪的 TODL 对 MCS 进行了验证，该 TODL 采用了三种不同的硅光子集成电路（PIC）实现。这三个 PIC 采用了基于热光、载流子注入和载流子耗尽效应的不同类型的相移器。所提出的 MCS 能够在所有测试的 PIC 中在 TODL 的整个范围内调整延迟。讨论了 MCS 对大规模光子波束形成器的可扩展性。
