Medical Library

Sidelobe reduction of tightly focused radially higher-order Laguerre-Gaussian beams using annular masks.
We report the reduction of sidelobes in tight focusing patterns of radially higher-order Laguerre-Gaussian (LG) beams with nonhelical phase structures. Numerical calculations based on the vectorial Debye theory reveal that a class of annular masks reduces sidelobes in the tight focusing […]

Distributed feedback fiber laser pumped by multimode laser diodes.
A distributed feedback fiber laser made of highly Er-Yb codoped phosphate glass fiber has been demonstrated experimentally. Efficient pump absorption allows for multimode pumping into the cladding of the active fiber. Output powers up to 160 mW have been achieved. The 35 mm long […]

Critical separation for efficient Tm(3+)-Tm(3+) energy transfer evidenced in nanostructured Tm(3+):Al(2)O(3) thin films.
Nanostructured amorphous Al oxide (a-Al(2)O(3)) thin films doped with Tm(3+) were synthesized by alternate pulsed laser deposition. The Tm(3+) ions have been deposited in layers with in-depth separation ranging from 0.75 to 6 nm. The films show two broad emission […]

Diamond nanocrystals hosting single nitrogen-vacancy color centers sorted by photon-correlation near-field microscopy.
Diamond nanocrystals containing highly photoluminescent color centers are attractive, nonclassical, and near-field light sources. For near-field applications, the size of the nanocrystal is crucial, since it defines the optical resolution. Nitrogen-vacancy (NV) color centers are efficiently created by proton irradiation and […]

Wavelength and intensity switching in directly coupled semiconductor microdisk lasers.
We demonstrate output wavelength and intensity switching in a three-element directly coupled microdisk device consisting of one spiral microdisk coupled to two semicircle microdisks. The gapless coupling mechanism used allows individual elements to achieve lasing while achieving optimal transfer of optical power between […]

Precision steering of an optical trap by electro-optic deflection.
We designed, constructed, and tested a single-beam optical trapping instrument employing twin electro-optic deflectors (EODs) to steer the trap in the specimen plane. Compared with traditional instruments based on acousto-optic deflectors (AODs), EOD-based traps offer a significant improvement in light throughput and a reduction […]

Interferometric polarization coherent anti-Stokes Raman scattering (IP-CARS) microscopy.
We report a novel interferometry-based polarization coherent anti-Stokes Raman scattering (IP-CARS) implementation for effectively suppressing the nonresonant background while significantly amplifying the resonant signal for vibrational imaging. By modulating the phase difference between the two interference CARS signals generated from the same sample and measuring […]

Spiral-path high-sensitivity silicon photonic wire molecular sensor with temperature-independent response.
We demonstrate a new silicon photonic wire waveguide evanescent field (PWEF) sensor that exploits the strong evanescent field of the transverse magnetic mode of this high-index-contrast, submicrometer-dimension waveguide. High sensitivity is achieved by using a 2 mm long double-spiral waveguide structure that fits […]

Fiber-based source of photon pairs at telecom band with high temporal coherence and brightness for quantum information processing.
We experimentally demonstrate a bright pulsed source of correlated photon pairs at the 1550 nm telecom band by pumping 300 m dispersion-shifted fiber with a 4 ps pulse train. We investigate the coherence property of […]

Enhanced chaos synchronization in unidirectionally coupled vertical-cavity surface-emitting semiconductor lasers with polarization-preserved injection.
We experimentally study chaos synchronization in unidirectionally coupled vertical-cavity surface-emitting semiconductor lasers (VCSELs) with polarization-preserved and polarization-selected optical injection. The measurements show, in agreement with theoretical predictions, that the maximum cross coefficient of 0.884 obtained with polarization-preserved optical injection is […]