Ultra-wideband heterogeneous integrated photodiodes on thin-film lithium niobate platform

Owing to its robust electro-optic coefficient and extensive transparency window, lithium niobate (LN) has grow to be a gorgeous photonic materials. Skinny-film lithium niobate (TFLN) know-how has enabled tight mode confinement and excessive nonlinear effectivity.

Numerous compact built-in photonics units have been realized on the TFLN platform, corresponding to compact high-performance modulators, polarization administration units, and broadband frequency comb sources. Nevertheless, the inherent problem of lithium niobate in realizing mild sources and photodetector poses a problem for the TFLN built-in photonics platform. As a vital optoelectronic element, an on-chip built-in high-performance photodetector is significant for TFLN photonic built-in chips.

In a brand new paper printed in Mild: Superior Manufacturing, a analysis crew, led by Professor Xiaojun Xie and Lianshan Yan from Key Laboratory of Photonic-Electrical Integration and Communication-Sensing Convergence, College of Info Science and Expertise, Southwest Jiaotong College, China, has reported a high-speed and high-responsivity modified uni-traveling service photodiodes heterogeneously built-in on the TFLN platform. The gadget displays a 3-dB bandwidth of 110 GHz and a responsivity of 0.4 A/W at a wavelength of 1,550-nm wavelength.

The fabrication course of was initialized by the dry etching of LN waveguides and passive units. A hybrid etching method was adopted to type gadget mesa. After steel plating and lift-off, the chips had been diced and polished. Epitaxial layer construction, LN waveguide geometry, and CPW pad geometry had been optimized to realize each massive bandwidth and excessive responsivity.

To additional assess the efficiency of the units, the crew utilized these units to an information transmission system and efficiently detected PAM4 alerts at 32 Gbaud with prime quality. It was demonstrated that the heterogeneously built-in photodiodes on TFLN platform have the potential to be utilized within the next-generation high-speed transmission techniques.

This work paves the best way to reaching massive-scale, multi-function, and high-performance TFLN photonic built-in circuits. Furthermore, it holds a promise for ultra-high-speed optical communications, high-performance built-in microwave photonics, and multi-function built-in quantum photonics.