A laser is disclosed having a housing formed of a block of glass-ceramic. The block is machined (or otherwise formed) to define one or more channels that act as a waveguide in two dimensions for light within the laser resonator. The channels extend between cavities also formed within the block which retain optical components of the laser, e.g. one or more of the gain medium, cavity mirrors, intermediate reflectors etc. The positioning, shape and size of each cavity is bespoke for the optical component it holds in order that each optical component is retained in optical alignment rigidly against the sides of the cavity.

Multi-clad optical fiber cladding light stripper (CLS) comprising an inner cladding with one or more recessed surface regions to remove light propagating within the inner cladding. A CLS may comprise such recessed surface regions along two or more azimuthal angles about the fiber axis, for example to improve stripping efficiency. One or more dimensions, or spatial distribution, of the recessed surface regions may be randomized, for example to improve stripping uniformity across a multiplicity of modes propagating within a cladding. Adjacent recessed surface regions may abut, for example, end-to-end, as segments of a recess that occupies a majority, or even an entirety, of the length of a fiber surrounded by a heat sink. One or more dimensions, or angular position, of individual ones of the abutted recessed surface regions may vary, according to a regular or irregular pattern.

A method and a laser for breaking through the limitation of fluorescence spectrum on laser wavelength is disclosed. The method includes: exciting electrons to a high energy level by pump light, and suppressing an oscillation of radiation light by laser cavity coating, using a laser resonance to enhance a transition probability of an electron-phonon coupling from the high energy level to a multi-phonon coupling level, so as to realize the emission and enhancement of breakthrough fluorescence spectrum and realize the radiation light oscillation, wherein the laser cavity includes an incident mirror, a folding mirror, a tuning element and an exit mirror arranged in sequence along an optical path direction, the laser gain medium is located between an incident mirror and a folding mirror in the laser resonator, and the tuning element is arranged in the laser cavity at a Brewster angle.

Multi-clad optical fiber cladding light stripper (CLS) comprising an inner cladding with one or more recessed surface regions to remove light propagating within the inner cladding. A CLS may comprise such recessed surface regions along two or more azimuthal angles about the fiber axis, for example to improve stripping efficiency. One or more dimensions, or spatial distribution, of the recessed surface regions may be randomized, for example to improve stripping uniformity across a multiplicity of modes propagating within a cladding. Adjacent recessed surface regions may abut, for example, end-to-end, as segments of a recess that occupies a majority, or even an entirety, of the length of a fiber surrounded by a heat sink. One or more dimensions, or angular position, of individual ones of the abutted recessed surface regions may vary, according to a regular or irregular pattern.

Multi-clad optical fiber cladding light stripper (CLS) comprising an inner cladding with one or more recessed surface regions to remove light propagating within the inner cladding. A CLS may comprise such recessed surface regions along two or more azimuthal angles about the fiber axis, for example to improve stripping efficiency. One or more dimensions, or spatial distribution, of the recessed surface regions may be randomized, for example to improve stripping uniformity across a multiplicity of modes propagating within a cladding. Adjacent recessed surface regions may abut, for example, end-to-end, as segments of a recess that occupies a majority, or even an entirety, of the length of a fiber surrounded by a heat sink. One or more dimensions, or angular position, of individual ones of the abutted recessed surface regions may vary, according to a regular or irregular pattern.

An optical resonator device, which can be implemented in a Brillouin laser, comprises a first waveguide ring resonator having a first diameter, and one or more second waveguide ring resonators adjacent to the first waveguide ring resonator. The one or more second waveguide ring resonators each have a second diameter that is less than the first diameter. The one or more second waveguide ring resonators optically communicate with the first waveguide ring resonator, such that an optical signal in the first waveguide ring resonator optically couples into the one or more second waveguide ring resonators. The one or more second waveguide ring resonators is configured such that when the optical signal resonates within the first waveguide ring resonator and the one or more second waveguide ring resonators, the optical signal within the first waveguide ring resonator is suppressed.

Methods, systems and apparatus are disclosed for delivery of pulsed treatment radiation by employing a pump radiation source generating picosecond pulses at a first wavelength, and a frequency-shifting resonator having a lasing medium and resonant cavity configured to receive the picosecond pulses from the pump source at the first wavelength and to emit radiation at a second wavelength in response thereto, wherein the resonant cavity of the frequency-shifting resonator has a round trip time shorter than the duration of the picosecond pulses generated by the pump radiation source. Methods, systems and apparatus are also disclosed for providing beam uniformity and a sub-harmonic resonator.

Methods, systems and apparatus are disclosed for delivery of pulsed treatment radiation by employing a pump radiation source generating picosecond pulses at a first wavelength, and a frequency-shifting resonator having a losing medium and resonant cavity configured to receive the picosecond pulses from the pump source at the first wavelength and to emit radiation at a second wavelength in response thereto, wherein the resonant cavity of the frequency-shifting resonator has a round trip time shorter than the duration of the picosecond pulses generated by the pump radiation source. Methods, systems and apparatus are also disclosed for providing beam uniformity and a sub-harmonic resonator.

The present disclosure discloses a method and apparatus for generating an optical frequency comb. The specific generation method comprises: receiving a pump laser that matches a thermally stable state of a nonlinear optical resonant cavity and causing the pump laser to oscillate in the nonlinear optical resonant cavity, such that a Brillouin gain corresponding to the pump laser coincides with a target longitudinal mode in the nonlinear optical resonant cavity; continuously generating a Brillouin laser at the target longitudinal mode in the case that a pump power of the pump laser exceeds a threshold for generating the Brillouin laser; and generating an optical frequency comb by using the Brillouin laser through a Kerr nonlinear four-wave mixing process. According to the technical solution of the present disclosure, the nonlinear optical resonant cavity with the Brillouin gain can generate an optical frequency comb in its thermally stable region. This optical frequency comb not only has good stability, but also has low quantum noise and narrow linewidth characteristics.

An optical resonator device, which can be implemented in a Brillouin laser, comprises a first waveguide ring resonator having a first diameter, and one or more second waveguide ring resonators adjacent to the first waveguide ring resonator. The one or more second waveguide ring resonators each have a second diameter that is less than the first diameter. The one or more second waveguide ring resonators optically communicate with the first waveguide ring resonator, such that an optical signal in the first waveguide ring resonator optically couples into the one or more second waveguide ring resonators. The one or more second waveguide ring resonators is configured such that when the optical signal resonates within the first waveguide ring resonator and the one or more second waveguide ring resonators, the optical signal within the first waveguide ring resonator is suppressed.