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When a fundamental beam propagates perpendicular to the optical axis of a nonlinear crystal with randomly distributed ferroelectric domains showing inverted sign of 2nd order nonlinearity (χ2), the generated second harmonic (SH) signal is spatially distributed in a plane, perpendicular to the optical axis [1]. Because the angular distribution of the SH intensity in this plane depends on the particular...
Vector beams are light beams with spatially variant polarization [1]. During the last decade vector beams have become an indispensable tool in many areas of science and technology such as optical trapping, quantum memories, and quantum optics. In particular, radially and azimuthally polarized light beams are the paradigm of vector beams. Radial vector beams are especially interesting due to the non-vanishing...
We investigate an ultrafast frequency and mode conversion process of orbital angular momentum (OAM) across the C-band in the high-index ring region of multimode fiber using intermodal nonlinear wave mixing, by in the best case up to 31.6% conversion efficiency.
Optical frequency comb generation due to interplay between second-order and third-order nonlinearities is demonstrated in a silicon nitride microring resonator which shows normal group velocity dispersion for the fundamental wave. Mode-locked bright and dark pulses are generated at the through and drop ports respectively.
Amplification of vortex beam in flash-lamp-pumped Nd:YAG amplifiers has been demonstrated. A maximum output pulse energy up to 995mJ has been achieved at 10 Hz in a 10 ns pulse, corresponding to an amplification efficiency of 295%. Second-harmonic generation of the amplified vortex output was performed using nonlinear a KD.P crystal. Maximum second-harmonic energy of 470mJ was generated. The joule...
YAl3(BO3)4 crystal enables the highest UV power of 1.8 MW and shortest pulse of 118 ps with power conversion efficiency of 37 % at 266 nm by using LBO crystal and Nd:YAG/Cr:YAG microchip laser.
Particle-in-cell simulations suggest that relativistic high-harmonic generation using overdense plasmas will be substantially enhanced by adding second harmonic to the incident laser field. This mechanism also offers a new diagnostic of the laser-plasma interaction.
The second harmonic signal at the output of an optically poled fiber was studied as a function of the input fundamental frequency power and polarization state. For an injected average power of 3 mW at 1064 nm, the measured output power at 532 nm was 10 μW. The second harmonic intensity profile was a bright green ring even if the pump was injected in the fundamental HE11 mode: we believe that the second...
We have studied the influence of the nonlinear interaction between the electromagnetic field and its conjugate ('negative frequency field') through the inclusion of new terms in the nonlinear polarisation. We have found that this new terms modify the usual nonlinear Self-phase modulation as well as giving rise to completely new phase-matched radiations emitted by light propagating in microresonators...
We investigate second-harmonic generation (SHG) efficiency in a waveguide-coupled photonic nanocavity. The factors for highly-efficient SHG are analyzed. It is found that 100% efficiency is achievable by introducing a mirror at the waveguide.
We demonstrate a miniature crystalline Raman laser operating at three discretely-tunable wavelengths in the green-yellow. Over 200 mW output powers were obtained for each wavelength with 3.8 W pumping. The threshold is below 0.4 W.
We present an efficient approach for broad band one way propagation of light by parallel and unequal dielectric waveguides leading different effective phase shifts. Three dimensional numerical simulations show that 30% operating bandwidth is achieved.
An experiment of second harmonic generation in a nonuniform crystal is presented, and interpreted in terms of an autoresonant wave-mixing theory. A good agreement is found between numerical simulations, analytical solutions and experimental data.
We design a 10-fold photonic quasi-crystal fiber (PQF) for analyzing the efficiency of second harmonic generation (SHG). In this study we emphasize on lowering two factors, namely, overlap area and wave-vector mismatch which determine the efficiency of SHG. We find a trade off variation between these two factors with increment in pitch. Finally we optimize the relative efficiency of SHG as 84.87 %W...
New applications require conveying huge bitrate from a source node to multiple destinations. As a result, point-to-multipoint (P2MP) connections need to be established on the optical layer. In this paper, the P2MP routing and spectrum allocation (RSA) problem is formally stated and modelled as an Integer Linear Program (ILP). Exhaustive numerical results show that creating several transparent sub-trees...
When the chalcogenide-tellurite hybrid optical fiber is pumped by an optical parametric oscillator with the pump wavelength from 1700 to 3000 nm, widely tunable second-harmonic generation (SHG) from 850 nm to 1502 nm is obtained.
We report the first experimental characterization of spectral coherence of Stokes-side continuum from fiber with two zero dispersion wavelength. We achieve 3-nJ, coherent Stokes pulses localized ∼1.28 µm from 300-fs Yb:fiber laser with 32% efficiency.
We present a comprehensive study of the physics and design of OPCPA based on chirped quasi-phase-matching, identifying subtle parametric processes occurring in these devices, and how they were addressed in our latest mid-IR OPCPA result.
We theoretically and experimentally show that fiber-optic analogues of event horizons can be explained by cascaded four-wave mixing of monochromatic continuous waves. Experiments performed with pulsed and continuous wave lasers are in excellent agreement.
We measure the ratio between fifth- and third-harmonic signals from air as a function of the laser intensity determined by mode measurements. Our results do not support the presence of a higher-order Kerr nonlinearity.
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