Dostart Nathan, Gevorgyan Hayk, Onural Deniz, Popović Miloš A
Opt Lett. 2021 Feb 1;46(3):460-463. doi: 10.1364/OL.408614.
Optical isolators, while commonplace in bulk and fiber optical systems, remain a key missing component in integrated photonics. Isolation using magneto-optic materials has been difficult to integrate into complementary metal-oxide-semiconductor (CMOS) fabrication platforms, motivating the use of other paths to effective non-reciprocity such as temporal modulation. We demonstrate a non-reciprocal element comprising a pair of microring modulators and a microring phase shifter in an active silicon photonic process, which, in combination with standard bandpass filters, yields an isolator on-chip. Isolation up to 13 dB is measured with a 3 dB bandwidth of 2 GHz and insertion loss of 18 dB. We also show transmission of a 4 Gbps optical data signal through the isolator while retaining a wide-open eye diagram. This compact design, in combination with increased modulation efficiency, could enable modulator-based isolators to become a standard 'black-box' component in integrated photonics CMOS foundry platform component libraries.
光隔离器在体光学和光纤光学系统中虽很常见，但在集成光子学中仍是关键的缺失组件。利用磁光材料实现隔离一直难以集成到互补金属氧化物半导体（CMOS）制造平台中，这促使人们采用其他实现有效非互易性的途径，如时间调制。我们展示了一种在有源硅光子工艺中由一对微环调制器和一个微环移相器组成的非互易元件，该元件与标准带通滤波器相结合，可在芯片上实现隔离器。测得的隔离度高达13 dB，3 dB带宽为2 GHz，插入损耗为18 dB。我们还展示了4 Gbps光数据信号通过隔离器的传输情况，同时保持了张开的眼图。这种紧凑的设计，再加上调制效率的提高，可能使基于调制器的隔离器成为集成光子学CMOS代工平台组件库中的标准“黑盒”组件。
