The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We perform an experimental demonstration of the physical mechanism utilized by most three party secret sharing protocols. By local operations at distant locations, we reduce and restore entanglement in a polarization entangled bipartite qubit system.
A practically tunable multiwavelength Raman fiber laser based on few-mode fiber Bragg gratings with dynamic range of more than 15 nm is investigated. We achieved a high extinction ratio of more than 45 dB.
Results on the inscription of Type IIA Bragg gratings in B-germanosilicate fibres using 248 nm, 500 fs laser radiation are presented. The gratings recorded exhibit index changes Deltan ap 10-3, while they remain intact for temperatures up to 650degC.
We change the pitch of interferometrically written 1-dimensional periodic structures by adjusting the frequency shift between two interfering beams. This technique is applicable to fabrication of both planar and fiber Bragg gratings.
We present the first low-threshold 1.55-mum grown on GaAs. The active layer was a single GaInNAsSb quantum well surrounded by strain-compensating GaNAs barriers. The room-temperature, continuous-wave, threshold current density was 579 A/cm2 and peak output power was 130 mW.
We demonstrate three-dimensional imaging by wide field optical coherence tomography with high-speed CMOS camera. A sample volume of 2.3times2.3times1.1mm3 (corresponding to 256times256times300 pixels) was imaged at 10 volumes/s by the scanning reference mirror.
Absorption cross-sections of the first excited singlet and triplet states of an asymmetric pentaazadentate porphyrin-like cadmium complex have been measured using Z-scans employing both 7.1-ns and 30-ps pulse widths, each at multiple pulse energies.
Enhancement and suppression of spontaneous emission in certain directions near the bandgap is observed for dye molecules in the centre of tapered photonic crystal fibres, as predicted by LDOS calculations, but not by the bandstructure.
Design and simulation are presented for a high-temperature intersubband Raman laser based on GaN/AlGaN coupled quantum wells. This laser is tunable over 3.6~5.2 mum by applying an electric field at a fixed pumping wavelength of 2.7 mum.
The first hyperpolarizabilities (beta) of several ldquoH-shapedrdquo second-order nonlinear optical chromophores measured by hyper-Rayleigh scattering technique exhibit much higher values than those of their monomers with slight absorption red shifting because of intra-molecular interactions.
We propose a new sensing method based on two quantum entangled beams. The effects caused by inserting polarizer or DNA solution into one beam can be also detected in the other undisturbed entangled beam.
We demonstrate uncooled 2.5 Gb/s operation up to 110degC of 1.3 mum GaInNAs double quantum well lasers with low threshold current and excellent temperature stability.
A synchronously pumped, fs-OPO with automated tuning in combination with an optimized scanner / microscope / detection system is used for MPE- and SHG microscopy on biological samples. The system and first results are presented.
We have demonstrated a beam scanning multi-photon multi-harmonic endoscope based on a flexible fiber bundle. Excited by a femtosecond Cr:Forsterite laser, multi-photon multi-harmonic excitation efficiencies are recovered without any external devices.
The 1.55 mum pulsed operation of an optically-pumped GaInNAsSb vertical-cavity surface emitting laser (VCSEL) is reported. Full temperature (10-50degC) and wavelength-dependent (1540-1560 nm) laser measurements were recorded. The annealing effect on laser performance is also shown.
Collective excitation, the leading technique for quantum information processing, suffers from limitations due to higher order excitations. We describe a blockade mechanism, based on light-shift imbalance in a Raman transition that eliminates this shortcoming.
Using terahertz magneto-photoconductive spectroscopy, we investigate impurity migration effects in barrier-doped GaAs/AlGaAs quantum wells. A new segregation decay rate for Si impurities in AlGaAs is determined for samples fabricated at low epitaxial growth temperature.
A balanced optical-RF phase detector for the extraction of low-jitter RF-signals from optical pulse trains, which is robust against drifts and photodetector nonlinearities, is presented. Sub-10 fs in-loop relative timing jitter is demonstrated.
The intensity-related carrier-envelope phase dynamics of octave-spanning Ti:sapphire lasers is investigated. Taking the laser gain dynamics into account, quantitative agreement between the measured and predicted carrier-envelope phase noise resulting from pump laser noise is achieved.
Two types of supermode noise, uncorrelated and correlated, are demonstrated for two different types of harmonically modelocked lasers. The correlated supermode noise is originated from the excitation of multiple correlated optical supermodes.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.