We experimentally demonstrate the phase locking of a two-dimensional (2D) array of four fiber lasers using an improved self-imaging resonator with a spatial filter. The high visibility interference round stripes of the coherent beam profile are observed. The coherent output power of the fiber array exceeds 134 W. The entire system operates quite stably, and no thermal effects observe in the spatial filter, indicating that the coherent output power can be increased using this method.