Fig. 1. Compressor schematic (asymmetric, out-of-plane): (a) top view; (b) side view. Green lines, beam at central frequency ; red lines, beam at arbitrary frequency shifted to the red part of the spectrum; AOPDF, acousto-optic programmable dispersive filter; AM, adaptive mirror.

Fig. 2. (a) Treacy compressor and (b) Littrow compressor. The difference of group velocity dispersion (GVD) of pulses in the near field and at the focal point: defocus (red), or vertical astigmatism (green), oblique astigmatism (blue) and the sum of three Zernike polynomials (black). The curves for defocus and direct astigmatism in Figure 2(a) coincide.

Fig. 3. (a) Treacy compressor and (b) Littrow compressor. Adjustment angle of the G4 grating in the x plane (solid curves) and in the y plane (dashed curves) for the grating shape shaped as defocus or vertical astigmatism (blue), oblique astigmatism (red) and the sum of three Zernike polynomials (black). In Figure 3(a), for oblique astigmatism and for defocus are equal to zero.

Fig. 4. (a) Treacy compressor and (b) Littrow compressor. Focal intensity (Strehl ratio) as a function of the rms of one grating surface for the grating shaped as defocus or vertical astigmatism (blue), oblique astigmatism (red) and the sum of three Zernike polynomials (black), plotted by approximate formulas: without compensation (Equation (50)) (dashed curves) and with compensation (Equation (54)) (dash-dotted curves correspond to , and dotted cures to ). The solid curves are plotted by the exact formula (Equation (49)).

Table 1. Parameters of different types of compressors ().