Laser apparatus, component, method and applications

A method for two-dimensional transverse mode selection in an optical resonator, comprising:

• providing an optical resonator having a feedback element at an end of the optical resonator, and an optical gain component coupled with the optical resonator;
• providing a reflecting volume Bragg grating (R-VBG) along an optical axis of the optical resonator, characterized by a reflection spectrum that falls within an amplification spectrum of the optical gain component, and a solid acceptance angle, wherein the R-VBG forms another end of the optical resonator;
• propagating a beam in the optical resonator along the optical axis to the R-VBG, wherein the propagating beam is characterized by a spectrum and a divergence angle;
• effecting a solid convergence angle of the propagating beam as it propagates to the R-VBG;
• adjusting the solid convergence angle of the propagating beam to at least partially fall within the solid acceptance angle of the R-VBG for the two-dimensional angular selection of at least one selected transverse mode.