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.

A bound states in the continuum (BIC) surface emitting laser includes a light emitter configured to generate BIC light waves. The laser also includes an array of holes with equal radii extending through the light emitter such that light emitted by the light emitter upon receipt of power is emitted as a coherent vortex beam at an angle to a surface normal of the light emitter that is determined at least in part by the radius of the holes in the array.

A surface-emitting laser includes a first reflector layer, an active layer provided on the first reflector layer, and a second reflector layer provided on the active layer. The second reflector layer includes a corner reflector that tapers in a direction opposite to the first reflector layer, and the corner reflector has a plan shape of a circle or a polygon with an even number of vertexes.

Disclosed is an all-fiber optical vortex laser based on resonance of orbital angular momentum modes. The all-fiber optical vortex laser has an annular cavity structure, and includes a narrow-linewidth pump laser, an optical amplifier, an orbital angular momentum mode generator, a first polarization controller, an optical fiber circulator, an optical fiber coupler, a second polarization controller and a vortex optical fiber. The orbital angular momentum mode generator (3) realizes directional conversion from a fundamental transverse mode in a single-mode optical fiber into an orbital angular momentum mode with a specific topological charge in a vortex optical fiber. The optical fiber coupler can realize directional coupling from an orbital angular momentum mode in one vortex optical fiber to an orbital angular momentum mode in another vortex optical fiber; the vortex optical fiber is an optical fiber supporting stable transmission of an orbital angular momentum model.

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.

A surface-emitting semiconductor laser includes a first emission region that outputs first light, and a second emission region that is provided separately from the first emission region, includes a phase shift section, and outputs second light. A far field pattern of the first light and a far field pattern of the second light are different from each other.

A laser ignition device includes a laser oscillation optical system that produces pulsed laser light, a condensing optical element that condenses the pulsed laser light into a combustion chamber, a housing that internally contains the condensing optical element, and an optical window that is provided distally with respect to the condensing optical element in the housing and transmits the pulsed laser light. The pulsed laser light is shaped as a ring around an optical axis at least at a light passage position in the optical window.

A photonic crystal laser 10 is a laser that has a configuration, in which a light emitting layer (an active layer 12) that generates light including light of wavelength .sub.L, and a two-dimensional photonic crystal layer 11 including different refractive index regions (holes 111) disposed two-dimensionally on a plate-like base material 112, the different refractive index regions having a refractive index different from a refractive index of the base material, so that a refractive index distribution is formed, are stacked. Each different refractive index region in the two-dimensional photonic crystal layer 11 is disposed at a position shifted from each lattice point of a basic two-dimensional lattice that has periodicity defined to generate a resonant state of light of the wavelength .sub.L by forming a two-dimensional standing wave and not to emit light of the wavelength .sub.L to outside. A positional shift vector r representing the shift of the position of the different refractive index region at the each lattice point from the lattice point is expressed by
r=d.Math.sin(G.Math.r+.sub.0).Math.(cos(L(+.sub.0)), sin(L(+.sub.0))) by using a wave number vector k=(k.sub.x, k.sub.y) of light of the wavelength .sub.L in the two-dimensional photonic crystal layer 11, an effective refractive index n.sub.eff of the two-dimensional photonic crystal layer, an azimuth angle from a predetermined reference line extending in a predetermined direction from a predetermined origin of the basic two-dimensional lattice, an arbitrary constant .sub.0, and a reciprocal lattice vector G=(k.sub.x|k|(sin cos )/n.sub.eff, k.sub.y|k|(sin sin )/n.sub.eff) expressed by using a spread angle of a laser beam, the position vector r of the each lattice point, arbitrary constants d and .sub.0, and an integer L excluding 0.

A semiconductor light emitting element that can form a useful beam pattern is provided. A semiconductor laser element LD includes an active layer 4, a pair of cladding layers 2 and 7 between which the active layer 4 is interposed, and a phase modulation layer 6 optically coupled to the active layer 4. The phase modulation layer 6 includes a base layer 6A and different refractive index regions 6B that are different in refractive index from the base layer 6A. The different refractive index regions 6B desirably arranged in the phase modulation layer 6 enable emission of laser light including a dark line with no zero-order light.

A light emitting device includes a substrate, and a stacked body provided to the substrate, and including a columnar part aggregate constituted by p columnar parts, wherein the stacked body includes a plurality of the columnar part aggregates, the p columnar parts each have a light emitting layer, a diagram configured by respective centers of the plurality of columnar parts has rotation symmetry when viewed from a stacking direction of the stacked body, a diametrical size of q columnar parts out of the p columnar parts is different from a diametrical size of r columnar parts out of the p columnar parts, a shape of the columnar part aggregate is not rotation symmetry, the p is an integer not less than 2, the q is an integer not less than 1 and less than the p, and the r is an integer satisfying r=pq.