Wide spectral bandwidth ultrashort laser pulse seed source with stable carrier-envelope phase

Abstract

The invention relates to a wide spectral bandwidth ultrashort laser pulse seed source with a stable carrier-envelope phase (CEP). The seed source comprises a pumping source, a parametric amplification system, a spectrum widening system and a dispersion compensation system. Two difference frequency processes in parametric amplification are utilized to generate light beams with stable CEPs; a dichroic mirror is used to carry out beam combination; the combined light beam is coupled by a lens and then enters a hollow fiber to carry out spectrum widening and pulse compression; and then, a femtosecond ultrashort laser pulse output that has a stable CEP and a continuous super-wide spectral bandwidth is obtained. According to the invention, the seed source is simple and is easy to operate; a gap problem during combination of light beams with different wave bands can be solved; continuous super-wide spectral bandwidths can be obtained; and a femtosecond ultrashort laser pulse output of a monocyclic order or even a sub-cyclic order can be obtained by compression, wherein the output has a stable CEP; therefore, the seed source can be widely applied to many fields like attosecond pulse generation, pumping detection and THz generation and the like.

Description

technical field [0001] The invention relates to an ultrashort laser pulse, in particular to a carrier envelope phase (abbreviated as CEP) stable wide spectral bandwidth ultrashort laser pulse seed source. The device uses a hollow fiber to output CEPs of different bands from two parameter amplification processes. The stable beam undergoes spectral broadening at the same time to obtain continuous ultra-wide spectral bandwidth, and obtains single-period or even sub-period femtosecond ultrashort laser pulses after compression. Background technique [0002] For cycle-scale laser pulses, the maximum value of the electric field intensity will change significantly in half a photoperiod, and the deviation between the peak value of the pulse electric field and the peak value of the pulse envelope is called the carrier envelope phase (CEP). Under different carrier phases, the oscillations of laser pulses with the same envelope are also very different, and their interactions with matter...

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Problems solved by technology

But when the two bands of light do not overlap, the coherently synthesized spectrum appears "broken"

Shu-Wei Huang et al. used waveform synthesis technology based on coherent wavelength division multiplexing to synthesize the light in the band with a center wavelength of 0.87um and the band with a center wavelength of 2.15um output by the Optical Parametric Chirped Pulse Amplification (OPCPA) process. The spectrum spans 1.8 octaves, and a subperiod non-sinusoidal waveform that can drive strong-field laser physics experiments is obtained (see "High-energy pulse synthesis with sub-cyclewaveform control for strong-field physics", Nature Photonics, Vol .5, Page 475-479, August 2011), because the two bands are not superimposed, the obtained spectrum is not continuous, which brings challenges to obtain periodic or even sub-periodic laser pulses

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