A photonic crystal surface-emitting laser includes a substrate, an n-type cladding layer, an active layer, an index matching layer and a photonic crystal structure. The n-type cladding layer is disposed over the substrate. The active layer is disposed over the n-type cladding layer. The index matching layer is disposed over the n-type cladding layer and is arranged around the active layer. The index matching layer is electrically insulating, and an effective refractive index of the index matching layer is substantially identical to an effective refractive index of the active layer. The photonic crystal structure is disposed over the active layer and the index matching layer.

In one example, a vertical cavity surface emitting laser (VCSEL) may include an active region to produce light at a wavelength, an emission surface to emit the light at the wavelength, a first oxide region spaced apart from the active region by a distance of at least a half-wavelength of the wavelength, a first oxide aperture in the first oxide region, a second oxide region between the first oxide region and the second oxide region, and a second oxide aperture in the second oxide region. The emitted light may have a divergence angle that is based on the respective positions and thicknesses of the first oxide region and the second oxide region.

Modification of the topology of selected regions of individual VCSEL devices during fabrication is utilized to provide an array output beam with specific characteristics (e.g., “uniform” output power across the array). These physical features include the width of the metal aperture, the width of the modal filter, and/or the geometry of the contact ring structure on the top of the VCSEL device. The modifications may also function to adjust the numerical apertures (NAs) of the devices, the beam waist, wallplug efficiency, and the like.

A beam deflection device includes multiple light-emission structures arranged adjacent to each other in a first direction (X direction). The light-emission structures are each configured to be capable of emitting, from its device surface, a line beam that extends in the first direction in the far field. Furthermore, the light-emission structures are each configured to allow the line beam to be scanned in a second direction (Y direction) that is orthogonal to the first direction.

A photonic crystal surface-emitting laser includes a substrate, an n-type cladding layer, an active layer, a photonic crystal structure, a p-type cladding layer, an n-type semiconductor layer and a meta-surface structure. The n-type cladding layer is disposed over the substrate. The active layer is disposed over the n-type cladding layer. The photonic crystal structure is disposed over the active layer. The p-type cladding layer is disposed over the photonic crystal structure. The n-type semiconductor layer is disposed over the p-type cladding layer. The meta-surface structure disposed on a surface of the n-type semiconductor layer away from the p-type cladding layer.

The present disclosure is generally directed to an EML with a filter layer disposed between an active region of the EML and a substrate of the EML to absorb a portion of unmodulated light energy, and preferably the unmodulated light energy caused by transverse electric (TE) substrate mode. The filter layer preferably comprises a material with an energy band gap (Eg) that is less than the energy band gap of the predetermined channel wavelength to absorb unmodulated laser light.

An on-chip miniarray of optically-coupled oxide-confined apertures of vertical cavity surface emitting lasers (VCSELs) is realized by etching holes from the chip surface down to at least one aperture layer. Oxidation of the aperture layer results in electrically-isolated apertures suitable for current injection. The lateral distance between the aperture centers and the shape of the aperture is chosen to result in effective interaction of the neighboring optical modes in the related aperture regions through optical field coupling effect causing the interaction-induced splitting of the wavelengths of the optical modes. At least one aperture has a different surface area due to different spacing of the etched holes. Different aperture sizes result in different wavelengths of the coupled modes. Splitting of the cavity modes in a frequency domain 3-100 GHz extends the modulation bandwidth of the device due to photon-photon interaction effects.

Selective deposition of highly reflective coating and/or anti-reflecting coating over apertures of different VCSELs foiining a miniarray allows stabilizing lasing in a single coherent mode of the array. Most preferably, highly reflective coating covers the largest aperture and stabilizes the fundamental mode of the coherent array. Anti-reflecting coatings can be deposited on at least one other aperture to reduce the photon lifetime and increase the homogeneous broadening of the related resonant wavelength. Consequently broadening of the photon-photon interaction resonances between the cavity modes can be controlled. Such resonance broadening allows control over the shape of the current modulation curve of the miniarray of VCSELs with the frequency maximum defined by the splitting of the cavity modes and the broadening defined by the broadening of the photon resonances. An increase in −3dB modulation bandwidth of the VCSEL miniarray up to at least 70 GHz is possible.

Such miniarray of VCSELs enables efficient coupling of the emitted light to a multimode optical fiber with the efficiency of at least 70%.

To achieve high-power single transverse mode laser, we here propose a supersymmetry (SUSY)-based triple-ridge waveguide semiconductor laser structure, which is composed of an electrically pumped main broad-ridge waveguide located in the middle and a pair of lossy auxiliary partner waveguides. The auxiliary partner waveguides are designed to provide dissipative modes that can phase match and couple with the higher-order modes in the main waveguide. By appropriately manipulating the gain-loss discrimination of the modes in the laser cavity, one can effectively suppress all the undesired higher-order transverse modes while keeping the fundamental one almost unaffected, thereby ensuring stable single-mode operation with a larger emitting aperture and accordingly a higher output power than a conventional single-transverse-mode ridge waveguide diode laser.

A semiconductor laser device includes a first conductivity type cladding layer having a refractive index n.sub.c1, a first conductivity type side optical guide layer, an active layer, a second conductivity type side optical guide layer, and a second conductivity type cladding layer of n.sub.c2 laminated in order on a first conductivity type semiconductor substrate, wherein an oscillation wavelength is λ, a first conductivity type low refractive index layer of n.sub.1 lower than n.sub.c1 having a thickness of d.sub.1 is provided between the first conductivity type side optical guide layer and the first conductivity type cladding layer, a second conductivity type low refractive index layer of n.sub.2 lower than n.sub.c2 having a thickness of d.sub.2 is provided between the second conductivity type side optical guide layer and the second conductivity type cladding layer, and a condition of a normalization frequency v.sub.2>v.sub.1 is satisfied.

A semiconductor light-emitting module according to the present embodiment includes a plurality of semiconductor light-emitting elements each outputting light of a desired beam projection pattern; and a support substrate holding the plurality of semiconductor light-emitting elements. Each of the plurality of semiconductor light-emitting elements includes a phase modulation layer configured to form a target beam projection pattern in a target beam projection region. The plurality of semiconductor light-emitting elements include first and second semiconductor light-emitting elements that are different in terms of at least any of a beam projection direction, the target beam projection pattern, and a light emission wavelength.