A novel device for achieving negative or positive dispersion and its applications

A known way to implement sufficiently efficient dispersion is based on a lo ng fiber (few kilometers). An alternative might be a configuration of grati ng pair that is more compact and adjustable. However, in such a configurati on negative dispersion (negative beta(2) coefficient. beta(2) is defined in eq. 1) cannot be achieved easily. In addition a real time control of dispe rsion coefficients is almost impossible. The combination between a positive and a negative dispersion medium in cascade is necessary for obtaining a d ispersion compensation of temporal signals. In this paper we suggest a nove l device that may be constructed to obtain both negative or positive disper sion coefficient. The suggested system is based on the all diffractive achr omatic Fourier transform setup. Using the suggested setup the amount of the negative or positive dispersion may be easily controlled.