Junction lasers which operate continuously at room temperature
TL;DR: In this paper, a double-heterostructure GaAs−Alx Ga1−x As injection laser which operates continuously at heat-sink temperatures as high as 311°K has been fabricated by liquid phase epitaxy.
Abstract: Double‐heterostructure GaAs–Alx Ga1−x As injection lasers which operate continuously at heat‐sink temperatures as high as 311°K have been fabricated by liquid‐phase epitaxy. Thresh‐olds for square diodes as low as 100 A/cm2 and for Fabry‐Perot diodes as low as 1600 A/cm2 have been obtained. Some details of preparation and properties are given.
Citations
More filters
TL;DR: In this paper, the authors proposed a quantum cascade laser consisting of a gain region (14) consisting of several layers (20) each including: alternating strata of a first type (28) defining each AllnAs quantum barrier and strata with injection barriers interposed between two of the layers.
Abstract: The invention concerns a quantum cascade laser comprising in particular a gain region (14) consisting of several layers (20) each including: alternating strata of a first type (28) defining each an AllnAs quantum barrier and strata of a second type (28) defining each an InGaAs quantum barrier, and injection barriers (22), interposed between two of the layers (20). The layers of the gain region (14) form each an active zone extending from one to the other of the injection barriers (22) adjacent thereto. The strata (26, 28) are dimensioned such that: each of the wells comprises, in the presence of an electric field, at least a first upper subband, a second median subband, and a third lower subband, and the probability of an electron being present in the first subband is highest in the proximity of one of the adjacent injection barriers, in the second subband in the median part of the zone and in the third subband in the proximity of the other adjacent barriers. The laser is formed by a succession of active zones and injection barriers, without interposition of a relaxation zone.
3,910 citations
TL;DR: In this article, a wide gap II-VI semiconductor alloy, MgxZn1−xO, was proposed for the fabrication of heteroepitaxial ultraviolet light emitting devices based on ZnO.
Abstract: We propose a widegap II–VI semiconductor alloy, MgxZn1−xO, for the fabrication of heteroepitaxial ultraviolet light emitting devices based on ZnO. The c-axis oriented MgxZn1−xO films were epitaxially grown by pulsed laser deposition on ZnO epitaxial films and sapphire (0001) substrates using ceramic targets. Solid solution films were prepared with Mg content up to x=0.33, achieving a band gap of 3.99 eV at room temperature. MgO impurity phase segregated at x⩾0.36. Lattice constants of MgxZn1−xO films changed slightly (∼1%), increasing in a axis and decreasing in c-axis direction with increasing x. These films showed ultraviolet photoluminescence at energies from 3.36 (x=0) to 3.87 eV (x=0.33) at 4.2 K.
1,441 citations
Proceedings Article•
[...]
TL;DR: In this article, the performance requirements for externally-modulated analog microwave photonic links are reviewed with specific emphasis placed on modulator efficiency, laser noise, detected photocurrent, and link linearity.
Abstract: An overview of analog microwave photonics will be presented. The performance requirements for externally-modulated analog microwave photonic links will be reviewed with specific emphasis placed on modulator efficiency, laser noise, detected photocurrent, and link linearity.
1,434 citations
Cites background from "Junction lasers which operate conti..."
...and with the development of double heterostructure devices capable of room-temperature continuous operation in 1970 [4], [5], this became the preferred source for optical communica-...
[...]
1,069 citations
Journal Article•
[...]
TL;DR: The development status of microwave photonic devices is reviewed, their systems applications are described, and some likely areas for future development are suggested.
Abstract: The low-loss wide bandwidth capability of opto-electronic systems makes them attractive for the transmission and processing of microwave signals, while the development of high-capacity optical communication systems has required the use of microwave techniques in optical transmitters and receivers. These two strands have led to the development of the research area of microwave photonics. This paper reviews the development status of microwave photonic devices, describes their systems applications, and suggests some likely areas for future development
646 citations
References
More filters
TL;DR: In this article, a double-heterostructure AlxGa1−xAs injection laser with room-temperature thresholds as low as 2300 A/cm2 has been prepared by solution epitaxy.
Abstract: Double‐heterostructure AlxGa1−xAs–GaAs– AlxGa1−xAs injection lasers with room‐temperature thresholds as low as 2300 A/cm2 have been prepared by solution epitaxy. These lasers have high gain and a low temperature coefficient of the threshold up to the highest temperatures measured, 380 °K.
123 citations
TL;DR: In this paper, the electrical and optical properties of GaAs-GaxAl1−xAs injection lasers produced by solution epitaxy are described and reproducibly prepared with Jth (300°K) about 10 000 A/cm2.
Abstract: The electrical and optical properties of GaAs–GaxAl1−xAs injection lasers produced by solution epitaxy are described. These lasers are composed of three layers, n‐GaAs, a thin p‐GaAs layer, and a p‐GaxAl1−xAs layer. In these lasers, the threshold current Jth is a strong function of the width of the p‐GaAs layer d, being optimum where d is about 2 μ. The temperature dependence of Jth is comparatively small below some maximum temperature TM, above which it increases very rapidly. The values of Jth obtained near room temperature for these lasers are lower than have previously been reported for injection lasers. Fabry‐Perot‐type diodes with cavities of about 400 μ may be reproducibly prepared with Jth (300°K) about 10 000 A/cm2. The lowest Jth (300°K) observed for one of these units was 8600 A/cm2. Units with fully internally reflected modes can be reproducibly prepared with Jth (300°K) ≈6000–7000 A/cm2. The low Jth (300°K) of these lasers is attributed primarily to carrier confinement, although improved opti...
119 citations
TL;DR: Germanium-doped GaAs were grown on GaAs seeds from Ga solution as mentioned in this paper and the properties of the Ge•doped GAAs layers were examined by Hall effect measurements from 20° to 400°K and by photoluminescence measurements between 12° and 300°K.
Abstract: Germanium‐doped GaAs crystals were grown on GaAs seeds from Ga solution. The properties of the Ge‐doped GaAs layers were examined by Hall effect measurements from 20° to 400°K and by photoluminescence measurements between 12° and 300°K. It was found that Ge‐doped GaAs is always p‐type when grown at 900°–875°C from Ga solution containing 56 at.% or less Ge. The temperature dependence of the Hall coefficient and the photoluminescence experiment indicated an acceptor energy level of 0.035 and 0.038 eV respectively. It was also found that at least 85% of the Ge was present as an acceptor in the GaAs crystals when the growth solution contained two atom percent or less Ge.
93 citations
TL;DR: In this article, a gallium arsenide stripe geometry junction laser has been operated continuously at a heat sink temperature of 200°K, which is the highest temperature yet attained in a continuous operation.
Abstract: Gallium arsenide stripe geometry junction lasers have now been operated continuously at a heat sink temperature of 200°K, which is the highest yet attained. The improvement is due to higher thermal conductivity resulting from (1) a heat sink made of type IIa diamond with a thermal conductivity of 45 W cm−1 °K−1 at 200°K, (2) an optimized stripe width near 12.5 μm and (3) an unusually thin diffused p region, 2.5 μm deep. This type of laser is unique in that the radiation pattern is Gaussian when measured parallel to the junction plane.
63 citations
60 citations