Change of Light-Pulse Shape by Nonlinear Amplification

V. S. Zuev, Vladimir A. Shcheglov

E G Lariontsev, V. N. Serkin

An analysis is made of the propagation of a frequency-modulated light pulse in a linearly amplifying medium with an inhomogeneously broadened gain profile. It is shown that a pulse can be compressed considerably during amplification. Conditions are established under which strong distortions of the pulse shape may result in its splitting. An analysis is made of the influence of the phase self-modulation of radiation on the shape of ultrashort light pulses in oscillators and amplifiers.

Rao Li, Daipeng Sui, Xiaochao Wang +1 more

Broadband low-coherence light has been applied in many fields such as optical imaging, atmospheric optical communication and laser inertial confinement fusion(ICF). It’s meaningful to investigate the temporal shaping technology of broadband low-coherence light. We propose and experimentally demonstrate a scheme of achieving all-optical arbitrary temporal shaping of broadband low-coherence light based on saturable absorption effect. Compared to traditional temporal shaping schemes such as electro-optic modulation(EOM) shaping or acousto-optic modulation(AOM) shaping, the modulation on the shaped pulse profile is much smaller, reduced from 14% (by acousto-optic modulator) to 3%(close to the ASE noise). Furthermore, we explore the evolution of shaped pulse contrast (intensity ratio between front edge and end edge) with the pump energy and contrast changing. The contrast of shaped pulse can be adjusted from 1:1.32 to 1:1.02 when pump contrast is 1:2, and from 1:2.25 to 1:1.90 when pump contrast is 1:3. And the maximum contrast of shaped pulse can reach 1:17 within the measurement accuracy. By changing the energy and contrast of pump, the contrast of the shaped pulse can be controlled flexibly. It’s useful to achieve all-optical arbitrary temporal shaping and pre-compensation during pulse amplification.

Rafael V Ambartsumyan, Nicolai G. Basov, V. S. Zuev +2 more

Avijit Lahiri

Boris I. Sturman, Evgeniy V. Podivilov, M. V. Gorkunov

We investigate theoretically the main elements of manipulation of light pulses---strong nonlinear slowing down, trapping, and release on demand---in photorefractive nonlinear media. This includes a study of the slowing-down characteristics, such as delay time, amplification factor, and nonlinear broadening, for different types of photorefractive response and interaction geometries, as well as an analysis of the shape of pulses released after a long storage. The photorefractive manipulation method is shown to be applicable at ambient temperatures, low light intensities, and wide spectral ranges.