METHOD FOR MODULATING A CARRIER LIGHT WAVE

摘要

Method for modulating a carrier light wave to achieve, a modulated light wave which carries information by symbols selected from a set of at least two different symbols. The light led through each path is phase-shifted by a respective total variable part phase shift, which for each path is the sum of at least three respective variable part phase shifts. Each variable part phase shift for each modulation state assumes one of two respective predetermined values, and each symbol is modulated using a respective combination of two such total variable part phase shifts. The modulation performed by the two paths is a PSK (Phase Shift Keying) modulation scheme, the group of symbols includes 2N unique symbols, the light led through each respective path is phase shifted using 2N−1 variable part phase shifts, and the respective difference between the respective predetermined values is the same for all variable part phase shifts.

主权项

1. Method for modulating a carrier light wave so that a modulated light wave is achieved, which modulated light wave carries information by means of symbols selected from a set of at least two different symbols, wherein the carrier light wave is led through a modulating interferometer comprising respective first and second parallel-coupled waveguiding modulation paths, wherein the carrier light wave is first split, subsequently led through said two paths and then recombined, wherein for modulating each respective symbol the respective light led through each respective path, between the said split and the said recombining, is phase shifted by a respective total variable part phase shift, which total variable part phase shift for each path is the sum of at least three respective variable part phase shifts, wherein each respective variable part phase shift for each modulation state assumes one of two respective predetermined values, and wherein each symbol in the said set of symbols is modulated using a respective combination of two such total variable part phase shifts, characterized in that the modulation performed by the two paths is a PSK (Phase Shift Keying) scheme, in that the said group of symbols comprises 2N unique symbols, in that the light led through each respective path is phase shifted using 2N−1 variable part phase shifts, and in that the respective difference between the respective predetermined values is the same for all variable part phase shifts.