Disclosed is a planar waveguide element including a first cylindrical lens disposed based on an z-axis and configured to collimate beams emitted from a plurality of emitters of a laser diode bar; a lens array configured to gather the beam emitted from each emitter via the first cylindrical lens; a plurality of first waveguides existing on an x-y plane by a number of the plurality of emitters and configured to gather at one place via a bending section; a taper configured to connect the lens array and each first waveguide, a width of the taper being narrower from the lens array to the plurality of first waveguide; and a combined waveguide configured to combine the plurality of first waveguides into one.