Abstract: Aspects of the present disclosure are directed to quantum processing systems that include a plurality of donor atom qubits positioned in a semiconductor substrate. The system also comprises a plurality of control gates configured to control the donor atom qubits. The system further comprises an SLQD charge sensor fabricated on/in the semiconductor substrate. The SLQD charge sensor is configured to sense spin-states of two or more donor atom qubits, which are positioned within a sensing range of the SLQD charge sensor.

Abstract: A laser device has a photonic crystal surface emitting laser (PCSEL) element. At a first lateral side of the PCSEL element, a reflector is arranged to reflect back into the PCSEL element at least a portion of light travelling out of the PCSEL element through the first lateral side of the PCSEL element. Between the first lateral side of the PCSEL element and the reflector there is interposed an electrically controllable light-transmission region configured to control the transmission of light from the PCSEL element to the reflector, based on an electrical input. Also disclosed is a method of operation of a corresponding laser device.

Abstract: A laser device has a photonic crystal surface emitting laser (PCSEL) element. At a first lateral side of the PCSEL element, a reflector is arranged to reflect back into the PCSEL element at least a portion of light travelling out of the PCSEL element through the first lateral side of the PCSEL element. Between the first lateral side of the PCSEL element and the reflector there is interposed an electrically controllable light-transmission region configured to control the transmission of light from the PCSEL element to the reflector, based on an electrical input. Also disclosed is a method of operation of a corresponding laser device.

Abstract: A laser structure comprising a first photonic crystal surface emitting laser (PCSEL), a second PCSEL, and a coupling region that extends between the first PCSEL and the second PCSEL along a longitudinal axis and that is electrically controllable so as to be capable of coherently coupling the first PCSEL to the second PCSEL. Each PCSEL include an active layer, a photonic crystal, and a two-dimensional periodic array distributed in an array plane parallel to the longitudinal axis within the photonic crystal where the two-dimensional periodic array is formed of regions having a refractive index that is different to the surrounding photonic crystal.

Abstract: A semiconductor light-emitting element includes: a lower clad layer 12 that is provided on a substrate 10; an active layer 20 that is provided on the lower clad layer 12 and includes a quantum well layer 24 and a plurality of quantum dots 28 sandwiching a second barrier layer 22b together with the quantum well layer 24; and an upper clad layer 14 that is provided on the active layer 20, wherein a distance D between the quantum well layer 24 and the plurality of quantum dots 28 is smaller than an average of distances X between centers of the plurality of quantum dots 28.

Abstract: A laser structure comprising a first photonic crystal surface emitting laser (PCSEL), a second PCSEL, and a coupling region that extends between the first PCSEL and the second PCSEL along a longitudinal axis and that is electrically controllable so as to be capable of coherently coupling the first PCSEL to the second PCSEL. Each PCSEL include an active layer, a photonic crystal, and a two-dimensional periodic array distributed in an array plane parallel to the longitudinal axis within the photonic crystal where the two-dimensional periodic array is formed of regions having a refractive index that is different to the surrounding photonic crystal.

Abstract: A semiconductor light-emitting element includes: a lower clad layer 12 that is provided on a substrate 10; an active layer 20 that is provided on the lower clad layer 12 and includes a quantum well layer 24 and a plurality of quantum dots 28 sandwiching a second barrier layer 22b together with the quantum well layer 24; and an upper clad layer 14 that is provided on the active layer 20, wherein a distance D between the quantum well layer 24 and the plurality of quantum dots 28 is smaller than an average of distances X between centers of the plurality of quantum dots 28.

Abstract: Embodiments of the present invention provided a method of fabricating a semiconductor light source structure. The method comprises providing a GaAs substrate; forming a lower cladding layer above the substrate, the lower cladding layer comprising an AIxGa1-xAs alloy; forming an active region above the lower cladding layer, the active region comprising a GaAs separate confinement heterostructure; and forming an upper cladding layer comprising an AIxGa1-xAs alloy above the active region in the form of an elongate stripe bounded on either side by an InGaP current-blocking layer, the elongate stripe defining an index-guided optical waveguide.

Abstract: A random number generator circuit includes a first memory having multiple storage elements. Each of the storage elements has an initial state corresponding thereto when powered up by a voltage supply source applied to the first memory. The first memory is operative to generate a first signal including multiple bits indicative of the respective initial states of the storage elements. The random number generator circuit further includes an error correction circuit coupled to the first memory. The error correction circuit is operative to receive the first signal and to correct at least one bit in the first signal that is not repeatable upon successive applications of power to the first memory to thereby generate a second signal. The second signal is a random number that is repeatable upon successive applications of power to the first memory.

Abstract: Embodiments of the present invention provided a method of fabricating a semiconductor light source structure. The method comprises providing a GaAs substrate; forming a lower cladding layer above the substrate, the lower cladding layer comprising an AIxGa1-xAs alloy; forming an active region above the lower cladding layer, the active region comprising a GaAs separate confinement heterostructure; and forming an upper cladding layer comprising an AIxGa1-xAs alloy above the active region in the form of an elongate stripe bounded on either side by an InGaP current-blocking layer, the elongate stripe defining an index-guided optical waveguide.

Abstract: A random number generator circuit includes a first memory having multiple storage elements. Each of the storage elements has an initial state corresponding thereto when powered up by a voltage supply source applied to the first memory. The first memory is operative to generate a first signal including multiple bits indicative of the respective initial states of the storage elements. The random number generator circuit further includes an error correction circuit coupled to the first memory. The error correction circuit is operative to receive the first signal and to correct at least one bit in the first signal that is not repeatable upon successive applications of power to the first memory to thereby generate a second signal. The second signal is a random number that is repeatable upon successive applications of power to the first memory.

Abstract: A photon source comprising: a quantum dot (21) having a first confined energy level capable of being populated with an electron and a second confined energy level capable of being populated by a hole; and supply means (23) for supplying carriers to the said energy levels, wherein the supply means are configured to supply a predetermined number of carriers to at least one of the energy levels to allow recombination of a predetermined number of carriers in said quantum dot to emit at least one photon.