Reconfigurable controlled two-qubit operation on a quantum photonic chip

Integrated quantum photonics is an appealing platform for quantum information processing, quantum communication and quantum metrology. In all these applications it is necessary not only to be able to create and detect Fock states of light but also to program the photonic circuits that implements some desired logical operation. Here we demonstrate a reconfigurable controlled two-qubit operation on a chip using a multiwaveguide interferometer with a tunable phase shifter. We find excellent agreement between theory and experiment, with a 0.98 \pm 0.02 average similarity between measured and ideal operations

Single Lateral Mode Mid-Infrared Laser Diode using Sub-Wavelength Modulation of the Facet Reflectivity

The characteristics of mid-infrared laser diodes have been investigated before and after the patterning of sub-wavelength metallic apertures on the emitting facet. Before modification of the facet the emitted spectrum consisted of a large number of peaks associated with different spatial modes, whereas afterwards the spectrum was dominated by a single peak. Simulations showed that the patterning of the facet caused the effective reflectivity to be different for each lateral mode, suggesting that the peak in the measured spectra is associated with the single lateral mode which is most strongly reflected from the modified facet.Comment: 12 pages, 3 figure

Midinfrared GaInSb/AlGaInSb Quantum Well Laser Diodes Grown on GaAs

The realization of midinfrared GaInSb/AlGaInSb type I quantum well diode lasers grown on GaAs is reported. Lasing was observed up to 95 K, at an emission wavelength of similar to 3.5 mu m, threshold current density of 115 A/cm(2), and with a characteristic temperature T-0 similar to 51 K.</p

Midinfrared GaInSb/AlGaInSb quantum well laser diodes grown on GaAs. .

The realization of midinfrared GaInSb/AlGaInSb type I quantum well diode lasers grown on GaAs is reported. Lasing was observed up to 95 K, at an emission wavelength of ~3.5 µm, threshold current density of 115 A/cm2, and with a characteristic temperature T0~51 K

GaInSb/AlInSb Multi-Quantum-Wells for Mid-Infrared Lasers

Photoluminescence (PL) from GaInSb/AlInSb type I multi-quantum-wells, grown on GaAs, has been investigated as a function of strain in the quantum wells. Luminescence, between 3 and 4 mu m, was observed for all samples, with good agreement between the measured and calculated peak emission energies. Analysis of the temperature dependence of the luminescence suggests that population of excited quantum well hole subbands occurs at high temperature, leading to a reduction in the PL signal. Room temperature luminescence was obtained from a sample with similar to 0.8% strain in the quantum wells. Preliminary results from laser diodes fabricated from companion wafers indicate lasing up to 220 K</p

Electroluminescence from InSb-based mid-infrared quantum well lasers.

InAsSb/InAsSbP double heterojunction lasers have been grown by liquid phase epitaxy in which free carrier absorption loss was investigated and minimized by the introduction of two undoped quaternary layers on either side of the active region. The diode lasers operate readily in pulsed mode at elevated temperatures and emit near 3.45 mu m with a threshold current density as low as 118 A/cm(2) at 85 K. Compared to the conventional 3-layer DH laser, reducing the optical loss increases the maximum lasing temperature by 95 K to similar to 210 K in the optimized 5-layer structure

Midinfrared GaInSb/AlGaInSb quantum well laser diodes operating above 200 K

Electroluminescence from GaInSb/AlGaInSb type I quantum well diode lasers, grown on GaAs, has been investigated as a function of strain in the quantum wells. Lasing was observed, in pulsed operation, up to temperatures of 161, 208, 219, and 202 K for structures containing 0.55%, 0.62%, 0.78%, and 1.1% strain, respectively, with lasing occurring at ~3.3 μm at 200 K for the 1.1% structureElectroluminescence from GaInSb/AlGaInSb type I quantum well diode lasers, grown on GaAs, has been investigated as a function of strain in the quantum wells. Lasing was observed, in pulsed operation, up to temperatures of 161, 208, 219, and 202 K for structures containing 0.55%, 0.62%, 0.78%, and 1.1% strain, respectively, with lasing occurring at ~3.3 μm at 200 K for the 1.1% structur

GaInSb/AlInSb multi-quantum-wells for mid-infrared lasers

Photoluminescence (PL) from GaInSb/AlInSb type I multi-quantum-wells, grown on GaAs, has been investigated as a function of strain in the quantum wells. Luminescence, between 3 and 4 μm, was observed for all samples, with good agreement between the measured and calculated peak emission energies. Analysis of the temperature dependence of the luminescence suggests that population of excited quantum well hole subbands occurs at high temperature, leading to a reduction in the PL signal. Room temperature luminescence was obtained from a sample with ∼ 0.8% strain in the quantum wells. Preliminary results from laser diodes fabricated from companion wafers indicate lasing up to 220 K