Provided is a vertical cavity surface emitting laser diode (VCSEL) with low compressive strain DBR layer, including a GaAs substrate, a lower DBR layer, a lower spacer layer, an active region, an upper spacer layer and an upper DBR layer. The lower or the upper DBR layer includes multiple low refractive index layers and multiple high refractive index layers. The lower DBR layer, the lower spacer layer, the upper spacer layer or the upper DBR layer contains Al.sub.xGa.sub.1-xAs.sub.1-yP.sub.y, where the lattice constant of Al.sub.xGa.sub.1-xAs.sub.1-yP.sub.y is greater than that of the GaAs substrate. This can moderately reduce excessive compressive strain due to lattice mismatch or avoid tensile strain during the epitaxial growth, thereby reducing the chance of deformation and bowing of the VCSEL epitaxial wafer or cracking during manufacturing. Additionally, the VCSEL epitaxial layer can be prevented from generating excessive compressive strain or tensile strain during the epitaxial growth.

A vertical cavity light-emitting element comprises a substrate, a first multilayer reflector formed on the substrate, a semiconductor structure layer formed on the first multilayer reflector and including a light emitting layer, a second multilayer reflector formed on the semiconductor structure layer and constituting a resonator together with the first multilayer reflector, and a light guide layer configured to form a light guide structure including a center region extending in a direction perpendicular to the upper surface of said substrate between the first and second multilayer reflectors and including a light emission center of the light-emitting layer and a peripheral region provided around the center region and having a smaller optical distance between the first and second multilayer reflectors than that in the center region. The second multilayer reflector has a flatness property over the center region and the peripheral region.

A coupled-cavity vertical-cavity surface-emitting laser (VCSEL) is disclosed. The coupled-cavity VCSEL includes a passive cavity and an additional distributed Bragg Reflector (DBR) not found in conventional VCSELs, all in a monolithic device. By including these two elements, the photon lifetime may be increased by a factor of approximately ten, leading to a reduction in the laser linewidth by a factor of approximately 100 compared to conventional VCSELs. The two additional elements also serve to ensure single-mode operation of the coupled-cavity VCSEL.

A semiconductor vertical light source includes upper and lower mirrors with an active region in between, an inner mode confinement region, and an outer current blocking region that includes a common epitaxial layer including an epitaxially regrown interface between the active region and upper mirror. A conducting channel including acceptors is in the inner mode confinement region. The current blocking region includes a first impurity doped region with donors between the epitaxially regrown interface and active region, and a second impurity doped region with acceptors between the first doped region and lower mirror. The outer current blocking region provides a PNPN current blocking region that includes the upper mirror or a p-type layer, first doped region, second doped region, and lower mirror or an n-type layer. The first and second impurity doped region force current flow into the conducting channel during normal operation of the light source.

A semiconductor vertical resonant cavity light source includes an upper and lower mirror that define a vertical resonant cavity. An active region is within the cavity for light generation between the upper and lower mirror. At least one cavity spacer region is between the active region and the upper mirror or lower mirror. The cavity includes an inner mode confinement region and an outer current blocking region. An index guide in the inner mode confinement region is between the cavity spacer region and the upper or lower mirror. The index guide and outer current blocking region each include a lower and upper epitaxial material layer thereon with an epitaxial interface region in between. At least a top surface of the lower material layer includes aluminum in the interface region throughout a full area of an active part of the vertical light source.

A light emitting element includes a stacked structure including, in a stacked state, a first light reflection layer 41 in which a plurality of thin films is stacked, a light emitting structure 20, and a second light reflection layer 42 in which a plurality of thin films is stacked. The light emitting structure includes a first compound semiconductor layer 21, an active layer 23 and, a second compound semiconductor layer 22 which are stacked. The light emitting structure 20 is formed with a light absorbing material layer 71 (32) in parallel to a virtual plane occupied by the active layer 23. Let the oscillation wavelength be .sub.0, let the equivalent refractive index from the active layer to the light absorbing material layer be n.sub.eq, let the optical distance from the active layer to the light absorbing material layer be L.sub.op, and let {(2m+1).sub.0}/(4n.sub.eq) (where m is an integer of equal to or more than 0), then, the value of L.sub.op is a value different from , and the thickness T.sub.ave of the second light reflection layer 42 is a value different from the theoretical thickness T.sub.DBR of the second light reflection layer 42.

Provided is a vertical cavity surface emitting laser diode (VCSEL) with multiple current confinement layers. A tunnel junction is generally required between two active layers to enable current to flow from one to another active layer. However, the tunnel junction will cause the current to spread in one active layer to become serious. As a result, the current in another active layer is difficult to be confined to the required area. Therefore, a current confinement layer with carrier and optical confinement functions is provided between two active layers such that the carrier and optical confinement of the active layers above and below the current confinement layer can be improved, thereby improving the performance of VCSEL. Compared with the existing VCSEL, the VCSEL with multiple current confinement layers can significantly improve the optical output power, slope efficiency and power conversion efficiency (PCE) of the VCSEL.

An array of monolithic wavelength division multiplexing (WDM) vertical cavity surface emitting lasers (VCSELs) with spatially varying gain peak and Fabry Perot wavelength is provided. Each VCSEL includes a lower distributed Bragg reflector (DBR), a Fabry Perot tuning/current spreading layer, and a structure comprising a multiple quantum well (MQW) layer sandwiched between a lower separate confinement heterostructure (SCH) layer and an upper SCH layer. The structure is sandwiched between the DBR and the Fabry Perot tuning/current spreading layer. Each MQW experiences a different amount of quantum well intermixing and concomitantly a different wavelength shift. Each VCSEL further includes a top mirror on the Fabry Perot tuning/current spreading layer. A method is also provided for manufacturing the array.

A vertical-cavity surface-emitting laser (VCSEL) and method of fabrication thereof is provided. The VCSEL includes a mesa structure disposed on a substrate. The mesa structure has a first reflector stack, a second reflector stack, and an active region disposed between the first and second reflector stacks. The active region is configured to cause the VCSEL to emit light having a characteristic wavelength of 910 nanometers. The active region includes alternating layers of quantum wells and barriers, the quantum wells having high indium content (up to 18%). The VCSEL features a first contact layer disposed at least partially on a surface of the mesa structure and configured to serve as an electrical signal layer and a second contact layer disposed at least partially about the mesa structure and configured to serve as an electrical ground.

A microelectromechanical systems (MEMS)-tunable vertical-cavity surface-emitting laser (VCSEL) in which the MEMS mirror is bonded to the active region. This allows for a separate electrostatic cavity that is outside the laser's optical resonant cavity. Moreover, the use of this cavity configuration allows the MEMS mirror to be tuned by pulling the mirror away from the active region. This reduces the risk of snap down. Moreover, since the MEMS mirror is now bonded to the active region, much wider latitude is available in the technologies that are used to fabricate the MEMS mirror. This is preferably deployed as a swept source in an optical coherence tomography (OCT) system.