A layered structure includes a first layer being a single material and a cavity coupled to the first layer. The first layer includes a porous region to form a first distributed Bragg reflector (DBR). The porous region includes alternating first porous and second porous sublayers of the single material to form the first DBR. The cavity includes an active region to generate radiation, detect radiation, or both. Advantageously, the layered structure and method of forming the layered structure improves the speed of manufacturing DBRs, reduces strain in the layered structure, reduces the size of the layered structure, and increases throughput.

A vertical cavity surface emitting laser (VCSEL) has first and second electrical contacts, and an optical resonator. The optical resonator has first and second distributed Bragg reflectors (DBRs), an active layer, a distributed heterojunction bipolar phototransistor (DHBP), and an optical guide. The DHBP has a collector layer, light sensitive layer; a base layer; and an emitter layer. There is an optical coupling between the active layer and the DHBP for providing an active carrier confinement by the DHBP. The optical guide guides an optical mode within the optical resonator during operation. The optical guide is outside a current flow which can be provided by the first and second electrical contacts during operation of the VCSEL. The optical guide is outside a layer sequence between the first and second electrical contacts in the vertical direction of the VCSEL. The optical guide has an oxide aperture arranged in the second DBR.

An adaptive thermal management system for a gas turbine engine includes a heat exchanger transferring heat into a coolant, a temperature sensor measuring a temperature of the coolant, and a sensor assembly that measures a parameter of the coolant during operation of the gas turbine engine. The parameter measured by the sensor assembly is indicative of a capacity of the coolant to accept heat from the hot flow. A control valve governs a flow of coolant into the heat exchanger. A controller adjusts the control valve to communicate coolant to the heat exchanger based on a determined capacity of the coolant to accept heat in view of the measured temperature of the coolant and that the measured parameter of the coolant is within a predefined range.

Provided is a back side emitting light source array device and an electronic apparatus, the back side emitting light source array device includes a substrate, a distributed Bragg reflector (DBR) provided on a first surface of the substrate, a plurality of gain layers which are provided on the DBR, the plurality of gain layers being spaced apart from one another, and each of the plurality of gain layers being configured to individually generate light, and a nanostructure reflector provided on the plurality of gain layers opposite to the DBR, and including a plurality of nanostructures having a sub-wavelength shape dimension, wherein a reflectivity of the DBR is less than a reflectivity of the nanostructure reflector such that the light generated is emitted through the substrate.

A method of manufacturing a vertical cavity surface emitting laser element including a first reflector including a nitride semiconductor multilayer film, the method includes: growing a first semiconductor layer consisting of a group III semiconductor containing aluminum and indium, the growing of the first semiconductor layer consisting of growing a first layer by supplying an aluminum source gas, an indium source gas, and a nitrogen source gas, and growing a second layer by supplying an aluminum source gas, an indium source gas, and a nitrogen source gas so that an indium composition ratio of the second layer is higher than an indium composition ratio of the first layer; and growing a second semiconductor layer consisting of gallium nitride. The growing of the first semiconductor layer and the growing of the second semiconductor are repeated alternately to form the nitride semiconductor multilayer film constituting the first reflector.

A light emitting element (10A) of the present disclosure includes: a stacked structure (20) in which a first compound semiconductor layer (21) having a first surface (21a) and a second surface (21b), an active layer (23), and a second compound semiconductor layer (22) having a first surface (22a) and a second surface (22b) are stacked; a first light reflecting layer (41) formed on a first surface side of the first compound semiconductor layer (21) and having a convex shape in a direction away from the active layer (23); and a second light reflecting layer (42) formed on a second surface side of the second compound semiconductor layer (22) and having a flat shape, in which a partition wall (24) extending in a stacking direction of the stacked structure (20) is formed so as to surround the first light reflecting layer (41).

A light emitting element according to the present disclosure includes a first light reflecting layer 41, a laminated structure 20, and a second light reflecting layer 42 laminated to each other. The laminated structure 20 includes a first compound semiconductor layer 21, a light emitting layer 23, and a second compound semiconductor layer 22 laminated to each other from a side of the first light reflecting layer. Light from the laminated structure 20 is emitted to an outside via the first light reflecting layer 41 or the second light reflecting layer 42. The first light reflecting layer 41 has a structure in which at least two types of thin films 41A and 41B are alternately laminated to each other in plural numbers. A film thickness modulating layer 80 is provided between the laminated structure 20 and the first light reflecting layer 41.

A vertical cavity surface emitting laser (VCSEL) has a shortened overall laser cavity by combining the gain section with a distributed Bragg reflector (DBR). The overall cavity length can be contracted by placing gain structures inside the DBR. This generally applies to a number of semiconductor material systems and wavelength bands, but this scheme is very well suited to the AlGaAs/GaAs material system with strained InGaAs quantum wells as a gain medium, for example.

A light emitting device, includes a selective growth mask layer 44; a first light reflection layer 41 thinner than the selective growth mask layer 44; a laminated structure including a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22, the first compound semiconductor layer 21 being formed on the first light reflection layer 41; and a second electrode 32 formed on the second compound semiconductor layer 22, and a second light reflection layer 42, in which the second light reflection layer 42 is opposed to the first light reflection layer 41, and the second light reflection layer is not formed on an upper side of the selective growth mask layer 44.

An oxide-confined vertical cavity surface emitting laser including a distributed Bragg reflector (DBR) wherein the layers of the (DBR) includes a multi-section layer consisting of a first section having a moderately high aluminum composition, an second section which is an insertion having a low aluminum composition, and a third section which is an oxide-confined aperture formed by partial oxidation of a layer having a high aluminum composition (95% and above). A difference in aluminum composition between a high value in the aperture layer and a moderately high value in the first section prevents non-desirable oxidation of the first section from the mesa side while the aperture layer is being oxidized. A low aluminum composition in the second section prevents non-desirable oxidation in the vertical direction of the layer adjacent to the targeted aperture layer.