New MDS Euclidean Self-orthogonal Codes

In this paper, a criterion of MDS Euclidean self-orthogonal codes is presented. New MDS Euclidean self-dual codes and self-orthogonal codes are constructed via this criterion. In particular, among our constructions, for large square $q$, about $frac{1}{8}cdot q$ new MDS Euclidean (almost) self-dual codes over $F_q$ can be produced. Moreover, we can construct about $frac{1}{4}cdot q$ new MDS Euclidean self-orthogonal codes with different even lengths $n$ with dimension $frac{n}{2}-1$.