Wavelength-tunable Tm:Y2O3 ceramic vortex laser with a changeable orbital angular momentum state

Wavelength -tunable orbital angular momentum (OAM) lasers with controllable topological charges have the potential for serving as light sources for large -capacity optical communication by combining conventional wavelength division multiplexing (WDM) with OAM mode -division multiplexing (OAM-MDM). In this study, we demonstrate a wavelength -tunable Tm-bulk laser that can control OAM states in the 2-mu m spectral range. The excitation conditions for different Laguerre-Gaussian (LG0,l) modes in a bulk laser cavity are theoretically determined by measuring the spatial propagation dynamics of the annular pump beam. As a proof -of -principle study, we experimentally generate OAM states of |h| and |2h| from a Tm : Y2O3 ceramic laser with a tunable emission wavelength using a Lyot filter (LF). The spatial properties of the scalar optical vortices are well conserved during wavelength tuning, indicating the feasibility of our approach for producing wavelength -tunable structured light. These OAM laser sources, which are characterized by their robustness and compactness, have potential applications in various areas such as optical communications, quantum optics, super -resolution microscopes, and more. (c) 2024 Optica Publishing Group