Yuxi Chu

High-contrast 2.0 Petawatt Ti:sapphire laser system

We report on a 2.0 PW femtosecond laser system at 800 nm based on the scheme of chirped pulse amplification using Ti:sapphire crystals, which is the highest peak power ever achieved from a femtosecond laser system. Combining the index-matching cladding technique and the precise control of the time delay between the input seed pulse and pump pulses, the parasitic lasing in the final booster amplifier is effectively suppressed at the pump energy of 140 J at 527 nm. The maximum output energy from the final amplifier is 72.6 J, corresponding to a conversion efficiency of 47.2% from the pump energy to the output laser energy. The measured spectral width of the amplified output pulse from the final amplifier is 60.8 nm for the full width at half-maximum (FWHM) by controlling the spectral evolution in the amplifier chain, and the recompressed pulse duration is 26.0 fs. The technology of cross-polarized wave (XPW) is applied in a broadband front-end, and the pulse contrast is improved to ~1.5 × 10¹¹ (-100 ps before the main pulse) which is measured at 83 TW power level with a repetition rate of 5 HZ.

High-energy large-aperture Ti:sapphire amplifier for 5 PW laser pulses

We report on the generation of 192.3 J centered at 800 nm wavelength from a chirped-pulse amplification (CPA) Ti:sapphire laser system. The experimental results demonstrate that parasitic lasing can be suppressed successfully in the final amplifier based on a Ti:sapphire crystal of 150 mm in diameter. An over 50% pump-to-signal conversion efficiency was measured for the final amplifier by optimizing the time delay of two pump pulses and enhancing the injected seed energy. With 72% compressor throughput efficiency and 27 fs long compressed pulse duration obtained at a lower energy level, this laser could potentially support a compressed laser pulse of 5.13 PW peak power. The experimental results represent notable progress regarding the CPA laser.

High-energy noncollinear optical parametric-chirped pulse amplification in LBO at 800 nm.

The optical parametric-chirped pulse amplification (OPCPA) based on large-aperture nonlinear optical crystals is promising for implementation of an ultrahigh peak-power laser system of 10 PW and beyond. We demonstrated the highest energy broadband OPCPA at 800 nm, to the best of our knowledge, by using an 80 mm in diameter LiB(3)O(5)(LBO) amplifier, with an output energy of 28.68 J, a bandwidth of 80 nm (FWHM), and conversion efficiency of 25.38%. After compression, a peak power of 0.61 PW with 33.8 fs pulse duration is produced.

Temporal compensation method of pulse distortion in saturated laser amplifiers

We provide a tunable temporal shaping method of a laser pulse to compensate pulse distortion in saturated laser amplifiers. The solutions of our computer programs, which express pulse distortion because of saturation effects in pulse laser amplifiers, determine the optimum input pulse shape required to produce a top-hat target pulse shape at the output of the saturated laser amplifier. With the tuning ability of the method provided here, the top-hat target pulse shape can be maintained at different output characteristic energies relative to the saturation energy of the amplifier. Moreover, the relation is experimentally verified using a solid-state laser amplifier chain. The method will prove useful in applications of high-energy laser amplifier systems that require a top-hat pulse shape to be efficient, such as the pump laser pulse of optical parametric chirped pulse amplification.

Latest Progress and Research Status of Ultra-high Intensity Lasers at SIOM

Based on technologies of chirped pulse amplification and optical parametric chirped pulse amplification, the peak power of petawatt femtosecond laser was upgraded. The hybrid scheme was confirmed to be an approach for ten patawatt laser.

Recent progress and research status of petawatt femtosecond lasers in SIOM

The latest progress towards a 10PW ultra-intense femtosecond laser at SIOM was reported. The energy of 192.3J was achieved with Ti: sapphire amplifiers, which could support a peak power of 5.13PW.