Patent ID: 8472807

Claim:
An optical field transmitter comprising: a light source; one or more DA converters; an optical field modulator; a complex information multilevel signal generator circuit that converts an information signal of a plurality of bits input at given time intervals into a complex multilevel information signal to output the complex multilevel information signal; and a phase pre-integration circuit that receives the complex multilevel information signal output from the complex information multilevel signal generator circuit and sampled at the given time intervals, and outputs phase pre-integration complex information obtained by integrating a phase component of the complex multilevel information signal by a given time interval in advance; wherein the one or more DA converters each convert the complex multilevel information signal including the phase pre-integration complex information output from the phase pre-integration circuit into an analog signal, and outputs the converted analog signal to the optical field modulator, wherein the optical field modulator modulates light output from the light source into a optical field signal by using the analog signal, and transmits the modulated optical field signal, wherein a phase angle of the complex multilevel information signal at a complex signal point is any one of values of integral multiples obtained by dividing 360 degrees by a positive integer N, wherein an amplitude value of the complex multilevel information signal at the complex signal point is any one of values of a positive integer M, and wherein a total number of the complex signal points that the complex multilevel information signal may take is lower than a product of N and M.