Patent ID: 8452189

Claim:
A transmitter for transmitting an optical signal through an optical fiber, comprising: an opto-electronic semiconductor device having at least three opto-electronic light sources disposed within a substantially circular emitting region and adapted to emit light substantially along an optical axis; a body assembly having an optical fiber coupling mateable with an end of the optical fiber, the opto-electronic semiconductor device mounted on a portion of the body assembly, the optical fiber coupling aligned with the optical axis and surrounding the circular emitting region, wherein a diameter of the circular emitting region is less than a diameter of the optical fiber; and a pulse amplitude modulation encoder, the pulse amplitude modulation encoder coupled to a source of a digital data stream and encoding the digital data stream into at least three pulse amplitude-modulated outputs, each pulse amplitude-modulated output having a plurality of amplitude states, a collective amplitude of the pulse amplitude-modulated outputs representing one of a plurality of unique symbols encoding a plurality of data bits of the digital data stream, at least one symbol of the plurality of unique symbols being represented by at least two pulse amplitude-modulated outputs having different amplitude states from each other, each of the pulse amplitude-modulated outputs coupled to a corresponding one of the at least three opto-electronic light sources.