One of the main problems in wind energy conversion system (WECS) is how to achieve maxim­u­m output power in different wind speeds. Maximum methods for maximum power point tracking in wind energy conversion syst­e­ms require the knowledge of system characteristics and mechanic sensors. So, using these methods practically will follow with high price and an abundant difficulties. In this pape...

We demonstrate the single-step generation of mid-infrared femtosecond laser pulses in a AgGaSe2 optical parametric oscillator that is synchronously pumped by a 100 MHz repetition rate sub-90 fs erbium fiber laser. The tuning range of the idler beam in principle covers ∼3.5 to 17 μm, only dependent on the choice of cavity and mirror design. As an example, we experimentally demonstrate...

By directly simulating Maxwell's equations via the finite-difference time-domain (FDTD) method, we numerically demonstrate the possibility of achieving high-efficiency second harmonic generation (SHG) in a structure consisting of a microscale doubly-resonant ring resonator side-coupled to two adjacent waveguides. We find that ≳ 94% conversion efficiency can be attained at telecom wavelengths, f...

We investigate frequency up-conversion of low power cw resonant radiation in Rb vapour as a function of various experimental parameters. We present evidence that the process of four wave mixing is responsible for unidirectional blue light generation and that the phase matching conditions along a light-induced waveguide determine the direction and divergence of the blue light. Velocity-selective...

High-power laser radiation with frequency u>i and wave vector ktz propagating through a plasma at an angle to a density ripple (0, fco) produces current and density perturbation at (u>i ,ki + ko). The density perturbation couples with the oscillatory velocity at (wi, fci) to produce nonlinear current at [2^'1.(2 A-1 + k0)] driving second-harmonic electromagnetic radiation. For a specific value ...

The research described in this publication was carried out by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. © 2012. All rights reserved. abstract. — An efficient laser transmitter design is proposed using resonant pumping of an erbium-doped fiber amplifier for a free-space optical communications source...

Spatio-temporal dynamics of singly resonant optical parametric oscillators with external seeding displays hexagonal, roll and honeycomb patterns, optical turbulence, rogue waves and cavity solitons. We derive appropriate mean-field equations with a sinc nonlinearity and demonstrate that offresonance seeding is necessary and responsible for the formation of complex spatial structures via selforg...

In this technical note the rf control and detection system for a detector of small harmonic displacements based on two coupled microwave cavities (PACO) is presented. The basic idea underlying this detector is the principle of parametric power conversion between two resonant modes of the system, stimulated by the (small) harmonic modulation of one system parameter. In this experiment we change ...