Background
Conventional semiconductor light sources emit photons as a result of an emission process within an active layer. However, efficiently exciting this layer presents a technical challenge, particularly when electrical operation is to be combined with resonant effects for the generation of indistinguishable single photons.
Technical Description
The present invention addresses this challenge by combining a ring-shaped pump section with an inner active layer arranged within this structure, thereby enabling resonant coupling of the pump radiation. More of the photons generated can actually be used instead of being lost in an uncontrolled manner. The special resonator structure increases the probability that a photon will be generated exactly when it is needed. Since the pump and emitter areas are integrated on a common semiconductor chip, the technology is easier to miniaturise and integrate into larger systems. The new structure allows active fine control of the excitation and emission wavelengths, and the number of useful photons per excitation process can be increased.
Possible Applications
Due to the potential for monolithic integration, the technology is particularly well-suited for compact semiconductor light sources and integrated photonic platforms based on compact, electrically driven single-photon sources.
Photons can be generated and utilised in a more targeted and reliable manner, with high indistinguishability and lower loss. This makes them particularly interesting for new technologies in quantum communication, quantum cryptography and future quantum computers, where high efficiency and control over individual photons with excellent quantum properties are crucial.
Schematic representation of the architecture, featuring a central emitter section (quantum dot) and a ring-shaped pump section for the resonant excitation of the quantum dots to generate indistinguishable photons. (© TUB/ChatGPTEdu)
