Investigation of Collimation and Polarization Characteristics of Multimode VCSEL Based on Metasurface Optoelectronic Integration

We propose a method based on metasurface optoelectronic integration to realize the collimation of multimode VCSEL and explore their polarization characteristics. By integrating a metalens with a focal length of
$\boldsymbol{630}\ \boldsymbol{\mu} \mathbf{m}$
on a
$\boldsymbol{7.5}\ \boldsymbol{\mu} \mathbf{m}$
oxide aperture VCSEL, we could maintain a small divergence angle (around 1.73°) under different operating currents. The near-field beam intensity profile show that the operating modes of VCSEL with
$\boldsymbol{7.5}\ \boldsymbol{\mu} \mathbf{m}$
oxide aperture are multi-transverse modes distributions. In addition, the multi-transverse modes of the VCSEL are obtained by superpositioning the
$\text{TEM}_{01}$
and
$\text{TEM}_{01}$
modes with orthogonal polarization directions through the external polarizer. This study provides valuable guidance for VCSEL in mode and polarization multiplexing, which has potential applications in optical communication and information encryption transmission.