Compact 100GBaud driverless thin-film lithium niobate modulator on a silicon substrate

• DOI: 10.1364/oe.458431
• Publication Date: 2022-06-16T16:00:07Z
• Authors: Gengxin Chen; Kaixuan Chen; Junwei Zhang; Ranfeng Gan; Lu Qi; Xuancong Fan; Ziliang Ruan; Zhenrui Lin; Jie Liu; Chao Lu; Alan Pak Tao Lau; Daoxin Dai; Changjian Guo; Liu Liu
• Keywords: 0103 physical sciences; 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; 01 natural sciences; 7. Clean energy

Electro-optic (EO) modulators with a high modulation bandwidth are indispensable parts of an optical interconnect system. A key requirement for an energy-efficient EO modulator is the low drive voltage, which can be provided using a standard complementary metal oxide semiconductor circuity without an amplifying driver. Thin-film lithium niobate has emerged as a new promising platform, and shown its capable of achieving driverless and high-speed EO modulators. In this paper, we report a compact high-performance modulator based on the thin-film lithium niobate platform on a silicon substrate. The periodic capacitively loaded travelling-wave electrode is employed to achieve a large modulation bandwidth and a low drive voltage, which can support a driverless single-lane 100Gbaud operation. The folded modulation section design also helps to reduce the device length by almost two thirds. The fabricated device represents a large EO bandwidth of 45GHz with a half-wave voltage of 0.7V. The driverless transmission of a 100Gbaud 4-level pulse amplitude modulation signal is demonstrated with a power consumption of 4.49fj/bit and a bit-error rate below the KP4 forward-error correction threshold of 2.4×10−4.