An optoelectronic transmitter including a semiconductor substrate, at least one laser source, and a high numerical aperture (NA) waveguide is provided. The laser source is disposed on the semiconductor substrate and configured to emit at least one laser beam. The high numerical aperture (NA) waveguide has an NA greater than or equal to 0.5 and is disposed on the semiconductor substrate. At least a part of the laser beam from the laser source enters the high NA waveguide, wherein no lens is disposed on the light path of the laser beam between the laser source and the high NA waveguide. An optoelectronic receiver and an optoelectronic transceiver are also provided.