1645-nm single-frequency vortex laser from an Er:YAG nonplanar ring oscillator

A 1645-nm single-frequency vortex beam with narrow linewidth from an Er:YAG nonplanar ring oscillator (NPRO) using an annular pump beam is demonstrated. The pump beam from a 1532-nm fiber laser is shaped to an annular beam by an axicon. The Er:YAG NPRO gener-ates a 1.96-W single-frequency vortex beam under a pump power of 13 W. The linewidth of the 1645-nm vortex laser is measured as 6 kHz. This work provides a convenient way of single-frequency vortex beam generation. (c) 2023 Optica Publishing Group

Automated summary

This study demonstrates the generation of a 1645-nm single-frequency vortex beam with narrow linewidth from an Er:YAG nonplanar ring oscillator (NPRO) using an annular pump beam. The pump beam, shaped by an axicon, is derived from a 1532-nm fiber laser. Under a pump power of 13 W, the Er:YAG NPRO generates a 1.96-W single-frequency vortex beam. The linewidth of the 1645-nm vortex laser is measured to be 6 kHz. This work presents a convenient approach for the generation of single-frequency vortex beams.