To provide a two-dimensional photonic crystal surface emitting laser capable of improving characteristics of light to be emitted, in particular, optical output power. The two-dimensional photonic crystal surface emitting laser 10X includes: a two-dimensional photonic crystal 123 including a plate-shaped base member 121 and modified refractive index regions 122 where the modified refractive index regions 122 have a refractive index different from that of the plate-shaped base member 121 and are two-dimensionally and periodically arranged in the base member; an active layer 11 provided on one side of the two-dimensional photonic crystal 123; and a first electrode 15A and a second electrode 16 provided sandwiching the two-dimensional photonic crystal 123 and the active layer 11 for supplying current to the active layer 11, where the second electrode 16 covers a region equal to or wider than the first electrode 15A, wherein the first electrode 15A is formed so as to supply the current to the active layer 11 with a different density depending on the in-plane position on the first electrode 15A.

A two-dimensional photonic-crystal surface-emitting laser 10 includes: a two-dimensional photonic crystal (two-dimensional photonic crystal layer 12) including a plate-shaped base body 121 having a predetermined size in which modified refractive index areas 122 whose refractive index differs from the base body are periodically arranged in a two-dimensional pattern; an active layer 11 provided on one side of the two-dimensional photonic crystal; and first and second electrodes 15 and 16 facing each other across the two-dimensional photonic crystal and the active layer 11, for supplying an electric current to the active layer 11. The modified refractive index areas 122 are provided in such a manner that the in-plane occupancy of those areas 122 in the base body 121 decreases, or the lattice constant for those areas 122 increases, in the direction from an outer edge toward the center of a current passage region 21 which is a region where the electric current passes through the two-dimensional photonic crystal. With this configuration, a stable laser oscillation can be obtained even when a temperature distribution which is lower at the outer edge and higher at the center of the current passage region is formed within the two-dimensional photonic crystal.

The present embodiment relates to a semiconductor light emitting element having a structure that enables removal of zero-order light from output light of an S-iPM laser. The semiconductor light emitting element includes an active layer, a pair of cladding layers, and a phase modulation layer. The phase modulation layer has a base layer and a plurality of modified refractive index regions each of which is individually arranged at a specific position. One of the pair of cladding layers includes a distributed Bragg reflector layer which has a transmission characteristic with respect to a specific optical image outputted along an inclined direction with respect to a light emission surface and has a reflection characteristic with respect to the zero-order light outputted along a normal direction of the light emission surface.

A vertical-cavity surface-emitting laser (VCSEL) may include at least one layer forming a grating structure with a selected period, depth, and fill factor, wherein the period, the depth, and the fill factor of the grating structure are configured to achieve greater than a threshold level of efficiency for the VCSEL, less than a threshold current increase caused by power loss from higher order diffraction associated with the grating structure, and greater than a threshold polarization selectivity at an emission wavelength of the VCSEL.

Embodiments described herein provide a layered structure that comprises a substrate that includes a first porous multilayer of a first porosity, an active quantum well capping layer epitaxially grown over the first porous multilayer, and a second porous multilayer of the first porosity over the active quantum well capping layer, where the second porous multilayer aligns with the first porous multilayer.

An electrically pumped surface-emitting photonic crystal laser includes an electric currents confinement structure arranged on a photonic crystal structure and an active layer with an opening, a transparent conducting layer arranged on the electric currents confinement structure and covering the photonic crystal structure, a metal anode arranged on the transparent conducting layer with an aperture. The photonic crystal laser has its epitaxy structure etched from above to fabricate the photonic crystal to allow laser beams to pass through with conductivity for the purpose of electrically pumping a quantum structure without complex technologies of wafer fusion bonding or epitaxial regrowth. Thereby the laser beams can be emitted from a front surface of the epitaxy structure with a narrow divergence angle.

Embodiments are notably directed to a vertical microcavity. The vertical microcavity includes a first reflector and a second reflector, each of which includes one or more material layers extending perpendicular to a vertical axis x. The cavity may further include a confinement region extending between the first reflector and the second reflector, so as to be able to confine an electromagnetic wave. The confinement region may include a single layer material, which is structured so as to create an effective refractive index variation for the electromagnetic wave to be confined, in an average plane of the single layer material, perpendicularly to said vertical axis x. Additional examples are further directed to related microcavity systems and methods of fabrication.

This disclosure describes a vertical-cavity surface-emitting laser (VCSEL) structure with a locked polarization and collimating optical element. The VCSEL structure comprises a grating, an optical emitter such as a lens and a plurality of GaAs/AlGaAs mirrors between the grating and the optical emitter. The grating located between the mirror stacks and above or below the active region is able to polarize incident waves of the VCSEL structure.

A two-dimensional photonic crystal including a plate-shaped base body in which modified refractive index areas differs from the base body are periodically arranged in a two-dimensional pattern; an active layer provided on one side of the two-dimensional photonic crystal; and first and second electrodes facing each other across the two-dimensional photonic crystal and the active layer, for supplying an electric current to the active layer. The modified refractive index areas are provided in the in-plane occupancy of areas in the base body increases, or the lattice constant for those areas decreases, in the direction from an outer edge toward the center of a current passage region where the electric current passes through the two-dimensional photonic crystal. A stable laser oscillation can be obtained when temperature distribution is lower at the outer edge and higher at the center of the current passage region is formed within the two-dimensional photonic crystal.

An apparatus for a photonic crystal surface emitting laser (PCSEL) device includes a PC cavity comprising a photonic crystal (PC) lattice comprising first nanoholes in a core region of the PC cavity, a plurality of lateral distributed Bragg reflector gratings (DBRs) that are truncated around the PC lattice, and opening regions between adjacent and truncated lateral DBRs around the PC lattice. The PCSEL devise also includes a multiple quantum well (MQW) layer coupled to the PC cavity in a vertical direction. The PCSEL device is configured to emit light in the vertical direction.