Spatial mode cleaning and efficient nonlinear pulse compression to sub-50 fs in a gas-filled multipass cell.

We demonstrate a gas-filled multipass cell (MPC) that cleaned the spatial mode of a spatial-filter-free 250 W, 100 kHz, 445 fs driven source based on an Innoslab amplifier and compressed the pulse duration to 41 fs simultaneously. The multipass cell acted as a spatial filter and benefited from its discrete waveguide nature, in which the input beam quality factor M was improved from 1.53 to a near-diffraction-limited value of 1.

Dual-slab Yb:KGd(WO) regenerative amplifier for spectral shaping and high-power output.

A high-power regenerative amplifier (RA) based on dual-slab Yb:KGd(WO) (Yb:KGW) was demonstrated, which provided a maximum average power of 33.7 W at a repetition rate of 75-200 kHz before compression with a central wavelength of 1039 nm, corresponding to an optical-to-optical conversion efficiency of 51.4%.

417 W, 2.38 mJ Innoslab amplifier compressible to a high pulse quality of 406 fs.

We demonstrate a 417 W, 175 kHz Innoslab chirped pulse amplification laser compressible to short and clean 406 fs pulse duration. A spectral bandwidth (full width at half maximum, FWHM) of ∼3 nm was maintained at full pump power, and the pulses exhibited good pulse quality in a wide tunable pulse energy range from 1.7 mJ to a maximum of 2.

Efficient high-power orthogonal dual-slab Yb:KGd(WO) laser oscillator with a TEM mode.

We demonstrated a TEM mode orthogonal dual-slab Yb:KG(WO)(Yb:KGW) laser oscillator with high average power. Polarization anisotropy of thermal lenses was investigated and alleviating the astigmatism based on orthogonal dual-slab. In addition, the laser polarization was directly controlled by adjusting the net gain of the two crystals.

Wavelength shift with a diode-pumped continuous-wave Yb:CALGO laser.

The dependence of an emission wavelength on the crystal temperature was first investigated for a diode-pumped continuous-wave ${{\rm Yb}^{3 + }}$Yb-doped ${{\rm CaGdAlO}_4}$CaGdAlO (Yb:CALGO) laser. A maximum output power of 11 W was obtained, corresponding to a slope efficiency of 19.8%.

[Water quality comparison between Lake Taihu and contribute river during high water-level period].

Thirty-two main rivers around Lake Taihu were sampled during high water period in 2008 to investigate river's vital impact on Lake water quality. Different forms of nitrogen and phosphorus were analyzed for the 32 river water samples according to nutrients function to algae. The aim of this study is to provide the basic information for river rehabilitation.