An optical element (10) according to the present invention is provided with a plurality of waveguides (11).about.(13) and a plurality of light path coupling parts (21), (22) coupling adjacent waveguides so as to optically couple said plural waveguides serially, wherein the paths for transmitting lights through the plural waveguides are curved at the optical path coupling parts, thereby the optical elements which is converted the incident laser light into the emitted light having uniform cross-sectional light intensity distribution can give a compact structure, further a laser light source that employs the optical element, and a two-dimensional image forming apparatus that employs the laser light source can also give a compact structure.