Diode-pumped wavelength-switchable visible Pr³⁺:YLF laser and vortex laser around 670 nm

Abstract

Here we developed a novel wavelength-switchable visible continuous-wave (CW) Pr 3+ :YLF laser around 670 nm. In single-wavelength laser operations, the maximum output powers of 2.60 W, 1.26 W, and 0.21 W, the maximum slope efficiencies of 34.7%, 27.3%, and 12.3% were achieved with good beam qualities (M 2 < 1.6) at 670.4 nm, 674.2 nm, and 678.9 nm, respectively. Record-high output power (2.6 W) and record-high slope efficiency (34.7%) were achieved for the Pr 3+ :YLF laser operation at 670.4 nm. This is also the first demonstration of longer-wavelength peaks beyond 670 nm in the 3 P 1 → 3 F 3 transition of Pr 3+ :YLF. In multi-wavelength laser operations, the dual-wavelength lasings, including 670.1/674.8 nm, 670.1/679.1 nm, and 675.0/679.4 nm, were obtained by fine adjustment of one/two etalons within the cavity. Furthermore, the triple-wavelength lasings, e.g. 672.2/674.2/678.6 nm and 670.4/674.8/679.4 nm, were successfully demonstrated. Moreover, both the first-order vortex lasers (LG 0 +1 and LG 0 -1 modes) at 670.4 nm were obtained by off-axis pumping.

Structured Light Laser Based on Intra-Cavity Modulation

“…Spiral phase plates of micron or submicron size can be Wavelength tunability is one of the most important capabilities of structured light lasers, particularly in the applications of optical communications [125,126]. In 2021, the first generation of LG 01 mode at 670.4 nm was reported with off-axis pumping by Lin X J [127]. The proposed Pr 3+ :YLF laser had the tuneable characteristic around the visible output wavelength.…”

Toroidal dipole response in rectangular waveguide: used to generate vector beams and vector vortex beams

“…Compared with the traditional vector beam and the vortex beam, the vector vortex beam is a new type of structured optical field with a helical phase and cross-sectional anisotropic polarization distribution, which has been proposed and explored in various applications, such as vector optical vortex filtering [22] , particle acceleration [23] , photon entanglement [24] , and photon spin Hall effect [25,26] . Driven by these applications, researchers have proposed many means to generate vector vortex beams, including using a spatial light modulator [27] , a laser resonator configuration [28,29] , a metasurface [30] , and a vector beam combined with spiral phase plate [31] . However, most of these methods face challenges of having a low damage threshold and a lower conversion efficiency, and require a large volume to manipulate the phase of the electromagnetic waves, making it difficult to reduce the overall volume.…”

Broadband and continuous wave pumped second-harmonic generation from microfiber coated with layered GaSe crystal

“…It is the same case in periodically poled fibers, where the unchanged poled period leads to the operation of only a narrow bandwidth determined by the quasi-phase matching 19 . Therefore, it is still a challenge to efficiently produce SH signal in a broad wavelength range under a continuous wave (CW) pump, which hinders the development of nonlinear parametric processes in various fields such as new wavelength light sources 20,21 , high-resolution microscope imaging 22 , and signal processing 23 .…”