Ultra-wideband Waveguide-coupled Photodiodes Heterogeneously Integrated on a Thin-film Lithium Niobate Platform

TL;DR

This paper reports the heterogenous integration of InP/InGaAs photodiodes on a thin-film lithium niobate platform, achieving record-high bandwidth and responsivity for advanced high-speed optoelectronic applications.

Contribution

It introduces a novel wafer-level heterogenous integration method for photodiodes on TFLN, enabling high-performance, large-scale photonic circuits.

Findings

Record-high 3-dB bandwidth of 110 GHz

Responsivity of 0.4 A/W at 1550 nm

Suitable for large-scale TFLN photonic integration

Abstract

With the advantages of large electro-optical coefficient, wide transparency window, and strong optical confinement, thin-film lithium niobate (TFLN) technique has enabled the development of various high-performance optoelectronics devices, ranging from the ultra-wideband electro-optic modulators to the high-efficient quantum sources. However, the TFLN platform does not natively promise lasers and photodiodes. This study presents an InP/InGaAs modified uni-traveling carrier (MUTC) photodiodes heterogeneously integrated on the TFLN platform with a record-high 3-dB bandwidth of 110 GHz and a responsivity of 0.4 A/W at a 1550-nm wavelength. It is implemented on a wafer-level TFLN-InP heterogeneous integration platform and is suitable for the large-scale, multi-function, and high-performance TFLN photonic integrated circuits.