Quasi-parametric chirped-pulse amplifier

Abstract

Quasi-parametric chirped-pulse amplifier comprising a signal path, a pump path, and an amplifier. A dedicated nonlinear crystal doped with rare-earth-ions is used which has strong absorption around the idler waveband. Both the chirped signal pulse and the pump pulse incident into the amplifier, where energy continuously transfers from the pump pulse to the signal pulse and a newly generated idler pulse. The energy of the generated idler pulse is continually absorbed by the rare-earth ions doped in the amplifier.

Description

CROSS-REFERENCE AND RELATED APPLICATIONS[0001]The subject application claims priority on Chinese patent application CN201510767075.7 filed on Nov. 11, 2015. The contents and subject matter of the Chinese priority application is incorporated herein by reference.FIELD OF INVENTION[0002]The present invention relates to ultrafast laser amplification, and more particularly, to a quasi-parametric chirped-pulse amplifier.BACKGROUND OF THE INVENTION[0003]Currently, intense chirped-pulse amplification lasers rely on two distinct types of optical amplifiers: optical parametric amplifiers (OPA) and conventional laser amplifiers. The OPA is superior to the energy-level laser amplification in terms of gain bandwidth; its combination with the chirped-pulse amplification is a promising technology for ultra-high peak power lasers. The exciting outcome is the opportunity to reach high peak powers close to a petawatt and generate few-cycle pulses with tens of millijoules of energy. However, the back-...

AI Technical Summary

Benefits of technology

[0004]The present invention provides a quasi-parametric amplifier (QPA) for chirped pulses, which inhibits the back-conversion effect and enables the signal amplification with high conversion efficiency and broad gain bandwidth.

[0008]In the present invention, a dedicated crystal with idler absorption is used in lieu of a conventional crystal in an OPA. The major advantage of the OPA such as broad gain bandwidth applies here as well, but the device of the present invention offers many additional benefits due to the absence of back-conversion: high signal efficiency toward theoretical limit and robustness against phase-mismatch.

[0009]In the saturation regime, the QPA exhibits nonparametric features as a laser amplifier with high signal efficiency approaching the theoretical limit and robustness against phase mismatch. In the small-signal regime, the QPA still exhibits the conventional parametric amplification.

[0010]Due to the inhibition of the back-conversion effect, the QPA has remarkable advantages of high conversion efficiency toward the quantum limit and robustness against phase mismatch, thereby relaxing the requirement on environmental temperature, beam divergence and pointing.

[0012]Remarkable efficiency and bandwidth properties, seen separately in conventional laser amplification and OPA, may be simultaneously acquired for QPA. It may overcome the limit of current technologies, and is promising for amplifying chirped pulse to much higher power level.

[0013]The quasi-parametric amplifier of the present invention exhibits nonparametric features as a laser amplifier, with high signal efficiency approaching the theoretical limit and robustness against phase mismatch; in the small-signal regime, it still belongs to the conventional parametric amplification. It has the main advantages of both the laser amplifier and the optical parametric amplifier, and can pave the way toward the design of ultra-high peak-power lasers.

Problems solved by technology

Such back-conversion effect is detrimental to the signal efficiency.

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