Medical and Biomedical Researches

In vivo nanosecond laser axotomy: cavitation dynamics and vesicle transport.

June 27th, 2008
In vivo nanosecond laser axotomy: cavitation dynamics and vesicle transport. Nanosecond laser pulses (lambda = 355 nm) were used to cut mechanosensory neurons in Caenorhabditis elegans and motorneurons in Drosophila melanogaster larvae. A pulse energy range of 0.8-1.2 microJ and < 20 pulses in single shot ...

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All optical switches based on the coupling of surface plasmon polaritons.

June 27th, 2008
All optical switches based on the coupling of surface plasmon polaritons. We studied the potentials of All Optical Switches (AOS) based on the intensity-dependent coupling and decoupling of light into the SPP modes (Surface Plasmon Polaritons) of a sinusoidally corrugated thin metal film (TMF), due to ...

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Enzymatic degradation of human skin dermis revealed by fluorescence and reflectance spectroscopy.

June 27th, 2008
Enzymatic degradation of human skin dermis revealed by fluorescence and reflectance spectroscopy. Dermis is the major source of the fluorescence and light scattering of skin. Tumor-induced degradation of the dermis is expected to change the fluorescence and light scattering properties of skin. To investigate how these ...

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Optical aberrations in a spinning pipe gas lens.

June 27th, 2008
Optical aberrations in a spinning pipe gas lens. If a heated pipe is rotated about its axis, a density gradient is formed which results in the pipe acting as a graded index lens. In this study we revisit the concept of a spinning pipe gas lens ...

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A semi-weakly confined erbium-doped waveguide amplifier with double-layered buffer/cladding.

June 27th, 2008
A semi-weakly confined erbium-doped waveguide amplifier with double-layered buffer/cladding. A semi-weakly confined waveguide structure was designed and fabricated. This waveguide structure has a 350 nm thin core layer. Its optical mode field is weakly confined in vertical direction but is strongly confined laterally. The waveguide can ...

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Electrical control of parametric processes in silicon waveguides.

June 27th, 2008
Electrical control of parametric processes in silicon waveguides. We demonstrate electrical tuning of phase mismatch in silicon wavelength converters. Active control of birefringence induced by a thin-film piezoelectric transducer integrated on top of the waveguides is used for dispersion engineering. The technology provides a solution for ...

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Controlled sub-nanometer tuning of photonic crystal resonator by carbonaceous nano-dots.

June 27th, 2008
Controlled sub-nanometer tuning of photonic crystal resonator by carbonaceous nano-dots. We propose and demonstrate a scheme that enables spectral tuning of a photonic crystal high-quality resonant mode, in steps finer than 0.2 nm, via electron beam induced deposition of carbonaceous nano-dots. The position and size of ...

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Reflection equalization of the simultaneous dispersion and dispersion-slope compensator based on a p

June 27th, 2008
Reflection equalization of the simultaneous dispersion and dispersion-slope compensator based on a phase-only sampled fiber Bragg grating. A novel approach for the reflection equalization of a phase-only sampled fiber Bragg grating (FBG) is presented, where the grating is specially designed as a simultaneous dispersion and dispersion-slope ...

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Digital holography of total internal reflection.

June 27th, 2008
Digital holography of total internal reflection. We introduce a new microscopy technique termed total internal reflection holographic microscopy (TIRHM). Quantitative phase microscopy by digital holography is used to image the phase profile of light in total internal reflection, which is modulated by the materials present on ...

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Solid state dye lasers based on LDS 698 doped in modified polymethyl methacrylate.

June 27th, 2008
Solid state dye lasers based on LDS 698 doped in modified polymethyl methacrylate. Broad band solid state dye lasers based on LDS 698 doped in modified polymethyl methacrylate (MPMMA) with laser wavelength about 650 nm were demonstrated. It was demonstrated that the fluorescence spectra of LDS ...

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Multi-cycle laser-driven broadband supercontinuum with a modulated polarization gating.

June 27th, 2008
Multi-cycle laser-driven broadband supercontinuum with a modulated polarization gating. We propose a method to generate broadband supercontinuum with a modulated polarization gating in the multi-cycle regime. The polarization gating at 1600 nm is employed to intensify the ellipticity dependence of high harmonic signal, and the adding ...

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Colloidal ZnO quantum dots in ultraviolet pillar microcavities.

June 27th, 2008
Colloidal ZnO quantum dots in ultraviolet pillar microcavities. Three dimensional light confinement and distinct pillar microcavity modes in the ultraviolet have been observed in pillar resonators with embedded colloidal ZnO quantum dots fabricated by focused ion beam milling. Results from a waveguide model for the mode ...

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Optical microscopic observation of fluorescence enhanced by grating-coupled surface plasmon resonanc

June 27th, 2008
Optical microscopic observation of fluorescence enhanced by grating-coupled surface plasmon resonance. On the substrate carrying a sub-wavelength grating covered with a thin metal layer, a fluorescent dye-labeled cell was observed by fluorescence microscope. The fluorescence intensity was more than 20 times greater than that on an ...

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Spectral behavior of thin film coated cascaded tapered long period gratings in multiple configuratio

June 27th, 2008
Spectral behavior of thin film coated cascaded tapered long period gratings in multiple configurations. In this work the spectral response of cascaded tapered long period gratings coated by nano-sized polymeric films has been investigated as function of the surrounding medium refractive index (SRI). The investigation was ...

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Quantitative phase imaging by three-wavelength digital holography.

June 27th, 2008
Quantitative phase imaging by three-wavelength digital holography. Three-wavelength digital holography is applied to obtain surface height measurements over several microns of range, while simultaneously maintaining the low noise precision of the single wavelength phase measurement. The precision is preserved by the use of intermediate synthetic wavelength ...

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Dual-band planar electric metamaterial in the terahertz regime.

June 27th, 2008
Dual-band planar electric metamaterial in the terahertz regime. We present the design, fabrication, and measurement of a dual-band planar metamaterial with two distinct electric resonances at 1.0 and 1.2 THz, as a step towards the development of frequency agile or broadband THz materials and devices. A ...

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Controlled waveforms on the single-cycle scale from a femtosecond oscillator.

June 27th, 2008
Controlled waveforms on the single-cycle scale from a femtosecond oscillator. We present an octave-spanning Ti:sapphire oscillator supporting Fourier-limited pulses as short as 3.7 fs. This laser system can be directly CEO-phase stabilized delivering an average output power of about 90 mW with a pulse duration of ...

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Cascaded wavelength conversion as favorable application of nonlinear optical polymers.

June 27th, 2008
Cascaded wavelength conversion as favorable application of nonlinear optical polymers. Nonlinear optical (NLO) polymers have been considered promising materials for wavelength conversion at a low pump power. However, they have not been readily adopted to practical applications due to their high absorption coefficients, especially at a ...

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Substantial gain enhancement for optical parametric amplification and oscillation in two-dimensional

June 27th, 2008
Substantial gain enhancement for optical parametric amplification and oscillation in two-dimensional chi(2) nonlinear photonic crystals. We have analyzed optical parametric interaction in a 2D NPC. While in general the nonlinear coefficient is small compared to a 1D NPC, we show that at numerous orientations a multitude ...

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Surface plasmon microcavity for resonant transmission through a slit in a gold film.

June 27th, 2008
Surface plasmon microcavity for resonant transmission through a slit in a gold film. We demonstrate the use of a compact surface plasmon (SP) microcavity formed in a 300 nm thick gold film to resonantly enhance the optical transmission through a subwavelength slit. Focussed ion beam milling ...

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A single-crystal source of path-polarization entangled photons at non-degenerate wavelengths.

June 27th, 2008
A single-crystal source of path-polarization entangled photons at non-degenerate wavelengths. We demonstrate a bright, narrowband, compact, quasi-phase-matched single-crystal source generating path-polarization-entangled photon pairs at 810 nm and 1550 nm at a maximum rate of 3 x 10(6) s(-1) THz(-1) mW(-1) after coupling to single-mode fiber, and ...

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Numerical investigation of quasi-coplanar plasmonic waveguide-based photonic components.

June 27th, 2008
Numerical investigation of quasi-coplanar plasmonic waveguide-based photonic components. Using 3-dimensional numerical simulations, we investigated the characteristics and performance of essential photonic components based on the recently proposed quasi-coplanar waveguide (QCPW) including bends, couplers, and splitters. The results confirmed the QCPW\'s potential in high density photonic integration. ...

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High-speed all-optical modulation using an InGaAs/AlAsSb quantum well waveguide.

June 27th, 2008
High-speed all-optical modulation using an InGaAs/AlAsSb quantum well waveguide. All-optical cross-phase modulation through the intersubband transition in an InGaAs/AlAsSb coupled quantum well was examined by using a sinusoidal intensity-modulated pump. For probe waves in the wavelength range of 1330-1620 nm and a pump modulation at a ...

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Planoconcave lens by negative refraction of stacked subwavelength hole arrays.

June 27th, 2008
Planoconcave lens by negative refraction of stacked subwavelength hole arrays. This work presents the design of a planoconcave parabolic negative index metamaterial lens operating at millimeter wavelengths fabricated by using stacked subwavelength hole arrays. A staircase approximation to the ideal parabola profile has been done by ...

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Supercontinuum generation in a water-core photonic crystal fiber.

June 27th, 2008
Supercontinuum generation in a water-core photonic crystal fiber. Supercontinuum generation is demonstrated in a 5-cm-long water-core photonic crystal fiber pumped near water\'s zero-dispersion wavelength. Up to 500-nm spectral width (evaluated at -20 dB from the peak) is achieved, while spectral widths were over 4 times narrower ...

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