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Selected Works

2006

Frequency combs

Articles 1 - 2 of 2

Full-Text Articles in Physics

Compression Of Laser Radiation In Plasmas Via Electromagnetic Cascading, Serguei Y. Kalmykov, Gennady Shvets Apr 2006

Compression Of Laser Radiation In Plasmas Via Electromagnetic Cascading, Serguei Y. Kalmykov, Gennady Shvets

Serge Youri Kalmykov

A train of few-laser-cycle relativistically intense radiation spikes with a terahertz repetition rate can be organized self-consistently in plasma from two frequency detuned co-propagating laser beams of low intensity. Large frequency bandwidth for the compression of spikes is produced via laser-induced periodic modulation of the plasma refractive index. The beat-wave-driven electron plasma wave downshifted from the plasma frequency creates a moving index grating thus inducing a periodic phase modulation of the driving laser (in spectral terms, electromagnetic cascading). The group velocity dispersion compresses the chirped laser beat notes to a few-cycle duration and relativistic intensity either concurrently in the same, …


Nonlinear Evolution Of The Plasma Beat Wave: Compressing The Laser Beat Notes Via Electromagnetic Cascading, Serguei Y. Kalmykov, Gennady Shvets Mar 2006

Nonlinear Evolution Of The Plasma Beat Wave: Compressing The Laser Beat Notes Via Electromagnetic Cascading, Serguei Y. Kalmykov, Gennady Shvets

Serge Youri Kalmykov

The near-resonant beat wave excitation of an electron plasma wave (EPW) can be employed for generating the trains of few-femtosecond electromagnetic (EM) pulses in rarefied plasmas. The EPW produces a comoving index grating that induces a laser phase modulation at the difference frequency. As a result, the cascade of sidebands red and blue shifted by integer multiples of the beat frequency is generated in the laser spectrum. The bandwidth of the phase-modulated laser is proportional to the product of the plasma length, laser wavelength, and amplitude of the electron density perturbation. When the beat frequency is lower than the electron …