Simultaneous generation of a frequency-multiplied and phase-shifted microwave signal with large tunability.

Abstract

We demonstrate a photonic approach to simultaneously realize a frequency-multiplied and phase-shifted microwave signal based on the birefringence effects in the high nonlinear fiber. The phase shift caused by asymmetric variations in refractive indexes of fiber between two orthogonal polarization states is introduced into two coherent harmonic of the modulated signals. By beating the phase-modulated sidebands, a frequency-multiplied microwave signal is generated and its phase can be adjusted by simply controlling the pump power. A microwave signal at doubled- or quadrupled-frequency with a full 2π phase shift is obtained over a frequency range from 10 GHz to 30 GHz. The proposed approach has the potential applications in the system with larger-broadband, higher-frequency and -data-rate system, even to handle a multi-wavelength operation.