Work

Suppressing mode partition noise in multimode VCSELs via lateral geometry control

Year: 2026

Type: article

Abstract: This study presents a geometry-driven approach to suppress mode partition noise (MPN) in multimode vertical-cavity surface-emitting lasers (VCSELs) for high-speed short-reach links. Three VCSELs with distinct lateral geometries were investigated, all exhibiting similar static and small-signal performance. The aperture geometry primarily determines the transverse modal distribution, where competition among different mode groups serves as the principal mechanism driving MPN. Among the designs, the intentionally engineered asymmetric aperture concentrates modal energy into a dominant mode group, yielding a root-mean-square (RMS) spectral width of 0.387 nm and the lowest low-frequency relative intensity noise (RIN). The device achieves a transmitter dispersion eye closure quaternary (TDECQ) of 0.86 dB in the back-to-back case and 1.24 dB after 100 m OM4 fiber transmission, with corresponding timing jitter of 6.65 ps and 8.03 ps. The results confirm that lateral-geometry optimization effectively suppresses MPN without degrading intrinsic performance, enabling higher-margin optical interconnects.

Source: Optics Express

DOI: 10.1364/oe.583350

Authors: Ting-Yu Wu, Yun-Cheng Yang, Taixian Zhang, Camel Shih, Chao-Hsin Wu

Language: English

Topic: Semiconductor Lasers and Optical Devices

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funders: National Science and Technology Council, Ministry of Education, National Taiwan University, National Chung-Shan Institute of Science and Technology