Researchers at the University of Cambridge in the UK published the results of the "Electrically driven and electrically tuneable quantum light sources" in the recent issue of Applied Physics Letters. Two quantum dot light-emitting diodes (LEDs) that are closely adjacent to each other can exert the effect of a tunable, all-electric quantum light source. In this experiment, the researchers used a light source emitted by an electrically excited LED to excite quantum dots of adjacent diodes. They can tune the quantum dot emission wavelengths from adjacent driving diodes through quantum confinement of the Stark effect. The researchers' idea is to generate entangled photon pairs for quantum computing applications via a wafer plane excitation structure that is easy to integrate into semiconductor components and photonic cavities. In this paper, a method of generating electrically triggered anti-bundled light from an electrically tunable light source is shown. The researchers designed 16 individually tunable diode structures on a single wafer. The component consists of a 180 x 210 μm planar microcavity LED containing a layer of indium arsenide (InAs) quantum dots embedded in a 10 nm arsenide ingot (GaAs) quantum well with an Al0.75Ga0.25As barrier layer. . A multi-distributed Bragg reflector (DBR) grown above and below the indium arsenide quantum dot layer and quantum well for forming a half-wavelength cavity to increase the vertical emission of the QD source portion while simultaneously acting as light from indium arsenide A horizontal waveguide layer that is wetted by the wetting layer. The p-type and the n-type are doped from the top DBR and the bottom DBR, respectively, to form a diode structure suitable for electrical excitation. The main idea is to "use the light generated by the LED to excite quantum dots of adjacent diodes." The LED operates with a forward bias, and its broad-band light emission from the indium arsenide wetting layer is horizontally directed by the Bragg mirror above and below the wetting layer. When a portion of the emitted light reaches the adjacent LED, some of the light source is absorbed by the wetting layer, generating excitons that can be drawn by the quantum dots in the adjacent diodes, thereby causing quantum light emission. The element has a p-type doped region (red), an intrinsic region (transparent), and an n-type doped region (blue). An LED emitting source (shown as a blue beam) that is strongly driven by forward bias (left) excites quantum dots (right) in adjacent elements. Quantum dots emit anti-convergence light (green). Since the cavity mode of the planar microcavity matches the emission wavelength of the adjacent quantum dots, the QD emission ratio up into the collection optics is increased. By changing the bias of the second diode, the tuning wavelength can be shifted by the Stark effect shift, and the light intensity emitted by the adjacent diode can be controlled by changing the voltage of the first diode. The researchers also demonstrated the ability to tune the exciton fine structure splitting in the second diode as a function of its overall electric field, allowing it to use such elements as a source of entangled photon pairs. Light emitted from the first diode (1) wetting layer is absorbed by the wetting layer of the adjacent diode, and a quantum light source is emitted after the diode generates charge carriers and is drawn through the quantum dots. The wetting layer emission (left) and quantum dot emission (right) are actual data, while the wetting layer absorption shown is a copy of the emission data and is only used to show the operating principle of the component. In the future, researchers hope to improve the efficiency of components and give more directionality between different diodes. It is possible to use a unidirectional antenna or a waveguide between LEDs to improve the efficiency of cross-coupling. In principle, one drive LED can excite many tunable LEDs. In combination with the fast electronic component and the low RC constant component, the "pump" can be adjusted by changing the bias of the diode (1), or by changing the bias of the diode (2) to adjust the wavelength. Entangled photons are emitted as needed. Source: Electronic Engineering Album Editor: Lilin Redundant Power Supply Series,Full Modular Redundant Power,800W Redundant Power Supplies,Redundant Server Power Supply 2000W Boluo Xurong Electronics Co., Ltd. , https://www.greenleaf-pc.com
