A vertical cavity surface emitting device includes a substrate, a first multilayer film reflecting mirror, a first semiconductor layer having a first conductivity type, a light-emitting layer, a second semiconductor layer having a second conductivity type opposite of the first conductivity type, and having an upper surface with a projection, an insulating layer that covers the upper surface of the second semiconductor layer and has an opening that exposes the second semiconductor layer on the upper surface of the projection terminated on the upper surface of the projection of the second semiconductor layer, a transmissive electrode layer that covers the upper surface of the second semiconductor layer exposed from the opening of the insulating layer and is formed on the insulating layer, and a second multilayer film reflecting mirror formed on the transmissive electrode layer and constituting a resonator together with the first multilayer film reflecting mirror.

The disclosed light source device includes a light emitting element including a first reflector, a second reflector, and a resonator spacer portion provided between the first reflector and the second reflector and including an active layer, and emits a first light as a laser beam and a second light as a spontaneous emission light, a light receiving element that determines an amount of the second light, and a determination unit that determines a timing at which the first light oscillates based on a decrease in the amount of the second light determined by the light receiving element.

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%.

Coupled-cavity vertical cavity surface emitting lasers (VCSELs) are provided by the present disclosure. The coupled-cavity VCSEL can comprise a VCSEL having a first mirror, a gain medium disposed above the first mirror, and a second mirror disposed above the gain medium, wherein a first cavity is formed by the first mirror and the second mirror. A second cavity is optically coupled to the VCSEL and configured to reflect light emitted from the VCSEL back into the first cavity of the VCSEL. In some embodiments, the second cavity can be an external cavity optically coupled to the VCSEL through a coupling component. In some embodiments, the second cavity can be integrated with the VCSEL to form a monolithic coupled-cavity VCSEL. A feedback circuit can control operation of the coupled-cavity VCSEL so the output comprises a target high frequency signal.

A microcavity pixel design and structure allowing for tuning the optical cavity length of the microcavity of a microcavity pixel structure. This is achieved by including an intermediate electrode in the device which has an overhang region to form a connecting area to a bottom electrode, alleviating design restrictions in material type and dimensions throughout the optical microcavity tuning process. A method for the fabrication of a multi-colored microcavity pixel array facilitating the use of blanket deposition methods for select layers within a microcavity pixel structure.

A surface emitting laser according to one embodiment of the present disclosure includes a mesa part including, in order, a first conductivity-type DBR layer, an active layer, a second conductivity-type DBR layer, and a second conductivity-type contact layer. The surface emitting laser further includes: a first conductivity-type contact layer provided in a region on the first conductivity-type DBR layer side in a positional relationship with respect to the mesa part; a first conductivity-type semiconductor layer that is disposed at a position opposed to the mesa part with the first conductivity-type contact layer interposed therebetween, and is in contact with the first conductivity-type contact layer, the first conductivity-type semiconductor layer having a lower impurity concentration than the first conductivity-type contact layer; a first electrode layer in contact with the first conductivity-type contact layer; and a second electrode layer in contact with the second conductivity-type contact layer.

Provided is a semiconductor laser diode including multiple active layers and a grating layer. The semiconductor laser diode includes two (or more than two) active layers, a grating layer, and a tunnel junction. The grating layer and the tunnel junction are provided between the two active layers. The tunnel junction is electrically connected to the two active layers, and the two active layers share and are optically coupled to the grating layer, thereby improving the external quantum efficiency and slope efficiency of the semiconductor laser diode.

A surface emitting laser includes a first reflective layer, an active layer provided on the first reflective layer, and a second reflective layer provided on the active layer. The first reflective layer, the active layer, and the second reflective layer form a mesa, and the mesa has an electrically insulating region and an electrically conductive region. The electrically insulating region is positioned at a center portion of the mesa in a surface direction, and the electrically conductive region includes the first reflective layer, the active layer, and the second reflective layer and is positioned outside the electrically insulating region in such a manner as to surround the electrically insulating region.

A light-emitting element includes: a laminated structure body 20 which is formed from a GaN-based compound semiconductor and in which a first compound semiconductor layer 21 including a first surface 21a and a second surface 21b that is opposed to the first surface 21a, an active layer 23 that faces the second surface 21b of the first compound semiconductor layer 21, and a second compound semiconductor layer 22 including a first surface 22a that faces the active layer 23 and a second surface 22b that is opposed to the first surface 22a are laminated; a first light reflection layer 41 that is provided on the first surface 21a side of the first compound semiconductor layer 21; and a second light reflection layer 42 that is provided on the second surface 22b side of the second compound semiconductor layer 22. The first light reflection layer 41 includes a concave mirror portion 43, and the second light reflection layer 42 has a flat shape.

A VCSEL may include an n-type substrate layer and an n-type bottom mirror on a surface of the n-type substrate layer. The VCSEL may include an active region on the n-type bottom mirror and a p-type layer on the active region. The VCSEL may include an oxidation layer over the active region to provide optical and electrical confinement of the VCSEL. The VCSEL may include a tunnel junction over the p-type layer to reverse a carrier type of an n-type top mirror. Either the oxidation layer is on or in the p-type layer and the tunnel junction is on the oxidation layer, or the tunnel junction is on the p-type layer and the oxidation layer is on the tunnel junction. The VCSEL may include the n-type top mirror over the tunnel junction, a top contact layer over the n-type top mirror, and a top metal on the top contact layer.