Compressors of negatively chirped pulses with internal telescope

Abstract

Features of compression of large-aperture negatively chirped amplified pulses of various aperture and durations up to a few-cycle in IR spectral regions are analyzed. Using the modified ray-tracing algorithm, the spectral-angular dependences of the radiation at different points of the beam cross section at the outputs of the grating compressors constructed according to the Offner, Martinez scheme and the scheme with a single-lens internal telescope are calculated. Offner compressor scheme has minimal aberrations and introduces a spectral angular chirp with a divergence much lower than the beam diffraction divergence. It was shown that in the region of 1.4 μm, negatively chirped pulses can be compressed down to near bandwidth limited duration of ~30 fs over the entire 40 mm beam aperture. It was also shown that, using stretchers with an internal telescope based on the Offner scheme, in the region of 3.6 μm it is possible to compress amplified negatively chirped pulses with duration of 40 ps and with a spectrum width close to an octave down to near bandwidth-limited duration of 18 fs duration at a 20 mm aperture.