Search results for "Physics::Optics"
showing 10 items of 1958 documents
Thermo-optic control of dielectric-loaded plasmonic waveguide components
2010
International audience; We report preliminary results on the development of compact (length 20%) is demonstrated with MZI-and WRR-based components, and efficient (similar to 30%) rerouting is achieved with DC switches. (C) 2010 Optical Society of America
Continuous wave dual-wavelength operation at 1048 and 1386 nm in Nd<sup>3+</sup>:LaBGeO<inf>5</inf> for yellow laser light ge…
2007
We present results on simultaneous oscillation in continuous-wave at 1048 and 1386 nm in Nd3+:LaBGeO5 crystal. LaBGeO5 is a nonlinear positive uniaxial crystal with potential application for intracavity generation of yellow laser radiation at 597 nm. Due to the different cross section in both laser channels, simultaneous oscillation is achieved by axial hole burning in a standing wave (linear cavity). It is concluded that a stable output laser spectrum is obtained for an absorbed pump power of 700 mW. A laser competition with alternating single-channel and dual-channel oscillation at different pump regimes was observed in the experiments.
Electromagnetically Induced Transparency and optical pumping processes formed in Cs sub-micron thin cell
2012
Abstract The Electromagnetically Induced Transparency (EIT) effect in a Λ -system formed by Cs atoms (6 S 1/2 − 6 P 3/2 − 6 S 1/2 ) confined in an extremely thin cell (ETC) (atomic column thickness L varies in the range of 800 nm –3 µm is studied both experimentally and theoretically. It is demonstrated that when the coupling laser frequency is in exact resonance with the corresponding atomic transition, the EIT resonance parameters weakly depend on L , which allows us to detect the effect at L = λ = 852 nm. EIT process reveals a striking peculiarity in case of the coupling laser detuned by Δ from the atomic transition, namely the width of the EIT resonance rapidly increases upon an in…
Passively mode-locked erbium-doped double-clad fiber laser operating at the 322nd harmonic
2009
International audience; We report passive mode locking of a soliton erbium-doped double-clad fiber laser operating at the 322nd harmonic of the fundamental cavity frequency. Repetition rates up to 3 GHz have been obtained with pulses of 1 ps duration and 18 pJ of energy. The supermode suppression at the 322nd harmonic is better than 25 dB. In addition, the transition dynamics from a bunched state of pulses to stable harmonic mode locking is presented, revealing a very long time scale.
Design and operation of CMOS-compatible electron pumps fabricated with optical lithography
2017
We report CMOS-compatible quantized current sources (electron pumps) fabricated with nanowires (NWs) on 300mm SOI wafers. Unlike other Al, GaAs or Si based metallic or semiconductor pumps, the fabrication does not rely on electron-beam lithography. The structure consists of two gates in series on the nanowire and the only difference with the SOI nanowire process lies in long (40nm) nitride spacers. As a result a single, silicide island gets isolated between the gates and transport is dominated by Coulomb blockade at cryogenic temperatures thanks to the small size and therefore capacitance of this island. Operation and performances comparable to devices fabricated using e-beam lithography is…
Near-Field Distribution of Optical Transmission of Periodic Subwavelength Holes in a Metal Film
2000
Recent experimental discovery of the enhanced optical transmission through metal films with periodic subwavelength holes has given rise to a considerable interest in the optical properties of such structures due to their possible numerous applications in optics and optoelectronics as well as rich physics behind the phenomenon of the transmission enhancement [1–4]. The transmission of a subwavelength aperture is very low and proportional to the fourth power of the ratio of its diameter and light wavelength. However, if a metal film is perforated with a periodic array of such holes, the optical transmission can be significantly enhanced [1]. Being normalized to the total area of the illuminat…
Characterization of a 10Hz double-pulse non-normal incidence pumped transient collisional Ni-like molybdenum soft x-ray laser for applications
2009
Stable and reliable operation of a nickel-like molybdenum transient collisional soft x-ray laser at 18.9 nm demonstrated and studied with a 10Hz Ti:sapphire laser system proves the suitability of the double-pulse non-normal incidence pumping geometry for table-top high repetition soft x-ray lasers and broadens the attractiveness of x-ray lasers as sources of coherent radiation for various applications. X-ray laser emission with pulse energies well above 1 μJ is obtained for several hours at 10Hz repetition-rate without re-alignment under optimized double pumping pulse parameters including energy ratio, time delay, pulse duration and line focus width.
Erbium-Doped-Silica Photonic Crystal Fiber Characterization Method: Description and Experimental Check
2010
The present paper reports and discusses a characterization method for erbium-doped-silica photonic crystal fibers based on the measurement of pump power attenuation and gain together with the McCumber theory. The absorption and emission cross sections and the passive losses of the fiber were obtained from a fitting procedure of theoretical to experimental values. The method was checked by means of a home-made photonic crystal fiber to verify its reliability. Finally, it was found that the characteristic parameters obtained by this method can be used to accurately simulate the performance of the fiber and therefore to design devices based on it.
Sloped-wall thin-film photonic crystal waveguides
2005
The effect of the slope of the groove walls in the behavior of thin-film one-dimensional photonic crystal waveguides is extensively studied. In this respect, we point out its influence on the modal dispersion relations and then on the bandgap structure in general. Likewise, we also prove the lack of accuracy in the evaluation of the bandgap edges when material dispersion is ignored. The extreme importance of both facts, the wall slope and the material dispersion, in the analysis and design of realistic photonic crystal devices is emphasized. In particular, we exploit the wall slope as a new design parameter. By suitably choosing the value of the above parameter, sloped-wall photonic crystal…
Tuning the propagation constant by the anti-crossing bandgap prism coupling technique.
2012
A novel plasmonic structure based on an anticrossing bandgap prism coupling technique is proposed. The study has been carried out using photonic crystals based on diffraction gratings (bounded by dielectrics with identical dielectric functions) together with a high refractive index prism to couple the long-range surface plasmon polaritons to photons. We analyse the structure and demonstrate the ability for tuning the propagation constants of plasmon modes by changing the thickness of the gold grating. The comparison to non-bandgap techniques is studied, and the influence of the plasmonic configuration on the plasmon propagation constant is discussed as well. Experimental measurements were a…