Optics and Photonics Society of Iran

In this paper, a stretcher system is designed based on refractive Martinez arrangement with a stretching coefficient of 3000 for a Gaussian 110 fs pulse laser at 810 nm. The spatial profile of the output pulse reveals low-quality output spot and high spatial chirping of the stretched pulse. Due to high spectral width of ultrashort femtosecond pulses, chromatic aberration of the lens becomes the most important factor in reducing the quality of output spot from stretching system. In this paper, the singlet-lens is therefore replaced by an appropriate achromatic doublet. The spatial profile of the output pulse represents a drastic reduction of spatial chirping for the stretched pulse in comparison with the singlet-lens system.