RESUMO
In this study, a novel metal-dielectric film mode filter structure that can flexibly regulate the transverse mode inside vertical-cavity surface-emitting lasers (VCSELs) is proposed. The number, volume, and stability of transverse modes inside the VCSEL can be adjusted according to three key parameters-the oxide aperture, the metal aperture, and the distance between the oxide aperture and the metal aperture-to form a flexible window, and a new parameter is defined to describe the mode identification. This study provides a complete simulation theory basis and calculation method, which is of great significance for the optical mode control in VCSELs.
RESUMO
We characterize laser generation in an ultralong air cavity (several meters in length) using an optical-pumped semiconductor gain chip for laser wireless charging applications. The study realizes laser generation in an external air cavity with a length of 200 cm, for the first time, and achieves a maximum output laser power of more than 86.3 mW. Furthermore, the laser oscillation can be maintained even when the output mirror of laser is off-axis within 1.6 cm. Thus, a long external cavity laser would ease the alignment between the laser beam and charging terminal, making it suitable for laser wireless charging applications.