Wavelength-versatile Laguerre-Gaussian mode source based on Pr³⁺: WPFG fiber laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Laguerre-Gaussian (LG) modes are crucial for advanced optical applications.
• Generating tunable LG modes across various visible wavelengths from a single compact source remains a challenge.

Purpose of the Study:

• To demonstrate direct generation of wavelength-versatile LG modes.
• To utilize a novel Pr3+-doped waterproof fluoro-aluminate glass fiber laser for visible light emission.
• To enable applications in super-resolution microscopy and laser nano/micro-fabrication.

Main Methods:

• Utilized a diode-pumped Pr3+-doped waterproof fluoro-aluminate glass (Pr3+:WPFG) fiber laser.
• Incorporated an intra-cavity lens with axial displacement for chromatic aberration and wavelength selection.
• Generated LG modes with positive and negative topological charges.

Main Results:

• Successfully generated LG modes at cyan (490 nm), green (523 nm), orange (605 nm), red (637 nm), and deep red (697 nm).
• Demonstrated wavelength versatility and control over topological charge.
• Achieved generation from a single, compact fiber laser system.

Conclusions:

• The Pr3+:WPFG fiber laser provides a versatile source of visible LG modes.
• The intra-cavity lens with chromatic aberration is key to wavelength selection.
• This compact laser source is expected to drive innovation in super-resolution microscopy and laser fabrication.