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We report the experimental generation of two-dimensional quantum turbulence in dilute-gas Bose-Einstein condensates by stirring the condensate with a laser beam, and the decay of the turbulent state to a large-scale flow in the form of a persistent current in a toroidal trap geometry. From numerical simulations of the stirring process, we characterize the dynamics of the quantized vortices in the...
A phase-contrast approach to generate arbitrary, low-noise dipole potentials is described. These potentials are dynamic and can be exploited for matter simulators and investigations from novel quantum behavior in 1–3 dimensions to atomtronics.
A variety of methods can be and are used for modelling optical tweezers. We examine applications of such modelling in the research literature, and consider the applicability and appropriateness of different methods of modelling.
Effects of fabrication conditions on an alternative type of pi-phase-shifted fibre Bragg grating at twice the Bragg wavelength were investigated, showing that slight variations in the alignment of phase mask affect the grating spectra.
A promising concept for making high-energy particle accelerators less expensive and more compact is to make use of axially polarized optical modes supported by line defect waveguides in three-dimensional photonic bandgap materials. Following a theoretical proposal by B. M. Cowan we here present the first experimental realization of corresponding pilot samples for three-dimensional photonic bandgap...
Bone tissue drilling experiments performed with the same femtosecond laser at NIR and UV wavelength are reported. The ablation threshold value of human mandible, which is the hardest bone of the skull, was also determined. It was not found significant difference between thresholds. UV ablation is more precise.
The relative-intensity-noise-to-phase-noise conversion induced by the photodetectors in the microwave synthesis from mode-locked lasers is investigated. A new and simple method is proposed to evaluate the noise conversion avoiding measuring the exact noise spectra.
The addition of structural modifications to enhance the temporal stability of the electro-optic (EO) chromophore, PYR-3, have not adversely affected the photostability. We find that the photostability can be enhanced by the addition of singlet oxygen quenchers.
Stable 200–400-MeV quasi-monoenergetic electron bunches (ΔE/E<10%), ∼ 10-pC charge, and no dark-current are produced when a self-injected laser plasma accelerator is optimized. PIC simulations demonstrate these beams are produced near the threshold for self-injection.
The rationale and design of a a 589-nm Laser Guide Star System, based on amplification of narrow-band diode laser seeds using ESO's patented Raman Fiber approach in the near infrared and subsequent resonant frequency doubling, developed and realized by two industrial partners is presented.
For quiver energies of electrons in a laser field close to the relativistic threshold, the interaction front with a target is stabilized based on relativistic properties against Rayleigh-Taylor instabilities
We report on the first experimental observation of higher-order modes guided by soliton-induced waveguides in nematic liquid crystals, identifying the power domains where guided modes are supported.
Low noise phase-locked lasers are essential for atom interferometry. A compact phase-locked laser system of low noise and high power is built by using a single laser diode and a single tapered amplifier chip. The light is modulated by an electro-optic modulator and the carrier mode is removed by a Febry-Perot cavity leaving the two sidebands of opposite phase to be used for the Raman transition.
We demonstrate self-trapped laser beams carrying optical vortices in nematic liquid crystals. We experimentally observe astigmatic transformations of vortex beams into spiralling dipole azimuthons accompanied by a nontrivial power-dependent charge-flipping of on-axis phase dislocations.
We report time-domain techniques of biophotonics sensing. Our bioprobes have been engineered to emit tunable luminescence across multiple sharp spectra and microsecond-long lifetimes. This offers high-throughput opportunities for cellular-level disease diagnosis at low cost.
We compare the sensitivity of an interferometric measurement of gravity using a freely-falling, lasing atomic source to that achieved with a cold, thermal atomic source. We observe a higher fringe visibility with the lasing source, also the highest yet observed in such a configuration. We improve sensitivity by exploiting large momentum transfer beamsplitting (LMT), and discuss briefly the advantages...
We report on our progress towards realization of a toroidal trap for Bose-Einstein condensates (BECs) of 87Rb using a time-averaged optical dipole potential. To achieve BEC we utilize a 20 W laser operating at 1064 nm to form an optical dipole trap in which we evaporatively cool the gas. Loading of the dipole trap is achieved by overlapping the dipole beams with a standard magnetic optical trap. Evaporative...
We observed the Purcell effect in a three-dimensional photonic crystal nanocavity with a single quantum dot. The enhancement and suppression factors of the spontaneous emission rate are ∼2 and 1.6, respectively.
In the last years, there has been a strong request of the physicians for point-of-care testing (POCT) instrumention. The present paper deals with the characterisation of a POCT optical instrument, the channel array interrogation (CAI) device, developed for the simultaneous detection of biomarkers for sepsis. The portable device was optimized for the determination of procalcitonin (PCT) and C-reactive...
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