Fibre products of superelliptic curves and codes therefrom

We construct new families of smooth projective curves over a finite field F_q with a lot of F_q-rational points. The genus in every such family is considerably less than the number of rational points, so the corresponding geometric Goppa codes have rather good parameters. Let X be a smooth projective curve of genus g=g(X) defined over a finite field F_q. The Goppa construction of linear [n,k,d]_q-codes associated to the curve X is described