The present disclosure relates to a three-dimensional cylindrical cavity-type
laser system capable of supporting circumferential radial emission. A cylindrical ring
waveguide provides optical confinement in the radial and axial dimensions thereby supporting a plurality of radial
modes, one of a plurality of axial
modes and a plurality of degenerate azimuthal
modes. These modes constitute a set of traveling wave modes which propagate around the cylindrical ring
waveguide possessing various degrees of optical confinement as quantified by their respective Q-factors. Index tailoring is used to tailor the radial
refractive index profile and geometry of the
waveguide to support radial modes possessing Q-factors capable of producing efficient radial emission, while
gain tailoring is used to define a
gain confining region which offsets
modal gain factors of the
modal constituency to favor a preferred set of modes supporting efficient radial emission out of the total
modal constituency supported by the
resonator. Under appropriate pump actuation the selected modes produce circumferential
laser radiation with the output surface comprising of the entire outer perimeter of the cylindrical ring waveguide. The design is applicable toward both micro-resonators and resonators much larger than the
optical wavelength, enabling high output powers and
scalability. The circumferential radial
laser emission can be concentrated by positioning the cylindrical
ring laser inside a three-dimensional conical mirror thereby forming a laser ring of light propagating in the axial dimension away from the surface of the laser, which can be subsequently collimated for focused using conventional
optics.