Nonlinear cascaded femtosecond third harmonic generation was experimentally investigated pumped by 100 fs pulses at optical communication band 1550 nm using a multi-grating 5 mol. % MgO-doped periodically poled lithium niobate crystal. The optimized efficiency of 10.8% was achieved with the simultaneous phase-matching of the second harmonic and sum frequency process. And the third harmonic spec...

1 Introduction Harmonic resonance, subharmonic and superharmonic entrainment, quasiperiodic and chaotic behavior are well known to occur in nonlinear self-oscillating systems which are subject to periodic forcing. Harmonic resonance occurs if the periodic forcing signal has a frequency very similar to the one of the undisturbed system and results in an amplification of the oscillations.

With advances in solid-state power electronic devices, control techniques (PWM) have been devised to obtain high dynamics responses from a multilevel conditioning converter-Photovoltaic. This work discusses the advantages and drawbacks of two different PWM techniques, sinusoidal (SPWM) technique Third harmonic injection (THIPWM) technique. These methods are compared by discussing their ease imp...

Reducing the capacitor voltage ripples of half-bridge submodules (HBSM) and full-bridge (FBSM) in a hybrid modular multilevel converter (MMC) is expected to reduce capacitance, volume, costs. To address this issue, article proposes dual harmonic injection method which injects second circulating current third-order into conventional MMC control. First, mathematical model proposed control establi...

A new scheme is presented to directly produce fundamental, second-, and third-harmonic three-color continuous-variable (CV) entangled beams by cascaded quasi-phase-matched third-harmonic generation (THG) in an optical cavity. THG can be achieved with high efficiency through a coupled sum-frequency process between the second-harmonic and the fundamental fields. It is demonstrated that the three ...

Nonlinear optical microscopy with sub-30 fs pulses from an Yb-fiber laser, approximately three times shorter than typical fiber laser pulses, leads to an order of magnitude brighter third harmonic generation imaging. Multiphoton fluorescence, second and third harmonic generation modalities are compared on stained microspheres and unstained biological tissues.