Continuous-wave laser oscillation in a Nd:YAG sphere.

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Neodymium-doped yttrium aluminum garnet (Nd:YAG) is a widely used laser gain medium.
• Spherical resonators offer unique optical properties compared to traditional linear cavities.
• Achieving stable, single-frequency oscillation in non-traditional laser geometries is an ongoing research challenge.

Purpose of the Study:

• To demonstrate continuous-wave laser oscillation in a Nd:YAG spherical resonator.
• To investigate the modal characteristics of spherical laser cavities.
• To compare experimental observations with theoretical predictions for spherical resonators.

Main Methods:

• Fabrication of a Nd:YAG spherical laser cavity.
• Excitation of the sphere using a selectively focused dye laser.
• Precise mode-matching techniques to achieve single-frequency oscillation.
• Analysis of emission patterns and comparison with theoretical models.

Main Results:

• Successful continuous-wave laser oscillation was observed in the Nd:YAG sphere.
• Single-frequency oscillation was achieved through careful mode matching.
• Experimental emission patterns closely matched theoretical predictions for spherically symmetric resonators.
• Observed modes were characterized by products of spherical harmonics and Bessel functions.

Conclusions:

• Spherical resonators can support stable, single-frequency laser oscillation.
• The modal behavior of spherical lasers differs significantly from linear cavities, exhibiting unique patterns.
• This work validates theoretical models for spherical resonators and opens avenues for novel laser designs.