Low-loss edge-coupling thin-film lithium niobate modulator with an efficient phase shifter
Ying Pan, Heyun Tan, Junwei Zhang, Mingbo He, Mengyue Xu, Xiaoyue Liu, Renyou Ge, Yuntao Zhu, Chuan Liu, Xinlun Cai
Abstract
Thin-film lithium-niobate-on-insulator (LNOI) is a very attractive platform for optical interconnect and nonlinear optics. It is essential to enable lithium niobate photonic integrated circuits with low power consumption. Here we present an edge-coupling Mach–Zehnder modulator on the platform with low fiber-chip coupling loss of 0.5 dB/facet, half-wave voltage <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="bold-italic">V</mml:mi> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="bold-italic">π</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> of 2.36 V, electro-optic (EO) bandwidth of 60 GHz and an efficient thermal-optic phase shifter with half-wave power of 6.24 mW. In addition, we experimentally demonstrate single-lane 200 Gbit/s data transmission utilizing a discrete multi-tone signal. The LNOI modulator demonstrated here shows great potential in energy-efficient large-capacity optical interconnects.