Repetition-Rate-Tunable Terahertz Optical Clock Generation Based on Optical Spectrum Synthesizer Using Attenuation and Phase-Tunable Arrayed Waveguide Grating

Recently, a number of high-speed optical clock generation technologies have been developed due to their potential useful applications in different fields of optical communication. We propose a new terahertz optical clock generation technique with a tunable repetition rate and a center wavelength. The proposed optical clock generator consists of a waveguide-type optical spectrum synthesizer using an attenuation and phase-tunable cyclic arrayed waveguide grating and a supercontinuum light generator. The optical spectrum synthesizer can generate arbitrary repetition rate pulse trains and a waveform by controlling each spectrum mode, using its variable optical attenuators and phase shifters. In this paper, we demonstrate optical clock generation with repetition rates of 1.28 and 2.56 THz experimentally.