Optical devices and methods of manufacturing and operating such optical devices. In an embodiment, an optical device includes a substrate, a multi-layer structure having a first surface in contact with a first surface of the substrate, a first mirror disposed over a second surface of the multi-layer structure, a second mirror disposed over a second surface of the substrate, an intermediate mirror within the multi-layer structure, and an optical gain structure within the multi-layer structure. The device may include a first optically resonant cavity within the multi-layer structure, bounded by the first mirror and the intermediate mirror, where the first optically resonant cavity includes the optical gain structure. The device may further include a second optically resonant cavity, bounded by the first and second mirrors, where the second optically resonant cavity includes the first optically resonant cavity, the second optically reflective layer, and the substrate.

Provided is an external cavity laser (ECL) including a vertical cavity surface emitting laser (VCSEL)-Distributed Bragg Reflector (DBR) type light emitting unit configured to receive a current and emit light, and including a DBR function layer and an active layer for a quantum well formed on one side of this DBR function layer, and an optical circuit unit including a light guide in which one end surface is installed to face an active layer at one side of the active layer, light generated from the active layer is received and guided, and an optical axis is formed vertically to an active layer plane, a reflection pattern that is formed at one side of the light guide so as to receive light output from the other end of the light guide to reflect the light again to the light guide, and an external layer for surrounding the light guide and the reflection pattern, wherein the VCSEL-DBR type light emitting unit and the optical circuit unit are mutually coupled to each other. An optical coupling efficiency in the ECL may be raised by improving an inefficient optical coupling issue including alignment, reflection, and the like in a coupling part of a gain element and a silicon waveguide.

A semiconductor laser including: a first mirror layer; a second mirror layer; an active layer, a current confinement layer, a first region, and a second region, in which the first mirror layer, the second mirror layer, the active layer, the current confinement layer, the first region, and the second region constitute a laminated body, the first region and the second region constitute an oxidized region of the laminated body, in a plan view, the laminated body includes a first part, a second part, and a third part disposed between the first part and the second part and resonating light generated in the active layer, and in a plan view, at least at a part of the third part, W1>W3 and W2>W3, W1 is a width of the oxidized region of the first part, W2 is a width of the oxidized region of the second part, and W.sub.3 is a width of the oxidized region of the third part.

A VCSEL can include: an elliptical oxide aperture in an oxidized region that is located between an active region and an emission surface, the elliptical aperture having a short radius and a long radius with a radius ratio (short radius)/(long radius) being between 0.6 and 0.8, the VCSEL having a relative intensity noise (RIN) of less than 140 dB/Hz. The VCSEL can include an elliptical emission aperture having the same dimensions of the elliptical oxide aperture. The VCSEL can include an elliptical contact having an elliptical contact aperture therein, the elliptical contact being around the elliptical emission aperture. The elliptical contact can be C-shaped. The VCSEL can include one or more trenches lateral of the oxidized region, the one or more trenches forming an elliptical shape, wherein the oxidized region has an elliptical shape. The one or more trenches can be trapezoidal shaped trenches.

A nitride semiconductor multilayer structure includes a first nitride semiconductor layer; a second nitride semiconductor layer; and a third nitride semiconductor layer formed between the first nitride semiconductor layer and the second nitride semiconductor layer. The third nitride semiconductor layer includes a first region and a second region that surrounds the first region in a same plane, and an indium content of the second region is lower than an indium content of the first region.

Disclosed herein is a system comprising: an optical system with a focal plane; an apparatus at the focal plane; a filter; wherein the apparatus comprises an array of vertical-cavity surface-emitting lasers (VCSELs) on a first substrate and an array of detectors on a second substrate, the detectors configured to detect laser beams that are emitted by the VCSELs and backscattered by an object; wherein the first substrate is mounted to the second substrate and is configured to allow the laser beams that are emitted by the VCSELs and backscattered by the object to transmit through the first substrate and reach the detectors; wherein the filter is configured to prevent light other than the laser beams from passing.

An apparatus comprises an array of vertical-cavity surface-emitting lasers (VCSELs) on a first substrate and an array of detectors on a second substrate, the detectors being configured to detect laser beams emitted by the VCSELs and backscattered by an object, wherein the first substrate is mounted to the second substrate and is configured to allow the laser beams emitted by the VCSELs and backscattered by the object to transmit through the first substrate and reach the detectors.

A time-of-flight sensor includes a substrate, a single photon avalanche detection chip, a vertical cavity surface-emitting laser, a first narrowband pass filter glass, and a second narrowband pass filter glass and a resin shell. The single photon avalanche detection chip is attached on the substrate, and the vertical cavity surface-emitting laser is also attached on the substrate. The first narrowband pass filter glass is arranged above the single photon avalanche detection chip, and the second narrowband pass filter glass is arranged above the vertical cavity surface-emitting laser. The resin shell covers the first narrowband pass filter glass and the second narrowband pass filter glass, and an upper surface of the first narrowband pass filter glass and an upper surface of the second narrowband pass filter glass are coplanar with an upper surface of the resin shell.

Provided is an external cavity laser (ECL) including a vertical cavity surface emitting laser (VCSEL)-Distributed Bragg Reflector (DBR) type light emitting unit configured to receive a current and emit light, and including a DBR function layer and an active layer for a quantum well formed on one side of this DBR function layer, and an optical circuit unit including a light guide in which one end surface is installed to face an active layer at one side of the active layer, light generated from the active layer is received and guided, and an optical axis is formed vertically to an active layer plane, a reflection pattern that is formed at one side of the light guide so as to receive light output from the other end of the light guide to reflect the light again to the light guide, and an external layer for surrounding the light guide and the reflection pattern, wherein the VCSEL-DBR type light emitting unit and the optical circuit unit are mutually coupled to each other.

According to the present invention, an optical coupling efficiency in the ECL may be raised by improving an inefficient optical coupling issue including alignment, reflection, and the like in a coupling part of a gain element and a silicon waveguide.

A VCSEL can include: an elliptical oxide aperture in an oxidized region that is located between an active region and an emission surface, the elliptical aperture having a short radius and a long radius with a radius ratio (short radius)/(long radius) being between 0.6 and 0.8, the VCSEL having a relative intensity noise (RIN) of less than 140 dB/Hz. The VCSEL can include an elliptical emission aperture having the same dimensions of the elliptical oxide aperture. The VCSEL can include an elliptical contact having an elliptical contact aperture therein, the elliptical contact being around the elliptical emission aperture. The elliptical contact can be C-shaped. The VCSEL can include one or more trenches lateral of the oxidized region, the one or more trenches forming an elliptical shape, wherein the oxidized region has an elliptical shape. The one or more trenches can be trapezoidal shaped trenches.