Photonic assisted arbitrary microwave signal generation based on opto-electronic oscillator

Abstract

We can achieve a high frequency with a low-phase-noise microwave photonics signal with the help of an optoelectronic oscillator (OEO). In this paper, we propose an OEO based on an external modulator and a dispersive component that provides frequency selection properties similar to those of the photonic filter, i.e. π phase-shifted fiber Bragg grating (π PS-FBG), which has a fixed center frequency of 1550nm. By changing the wavelength of an optical carrier signal, we can tune the oscillating frequency of the OEO. The π PS-FBG reflected signal was passed through parallelly connected single-mode fibers of 0.1 Km, 0.2 Km, and 0.4 Km length. An extra delay in the loop is provided for locking the oscillating frequency. we use π PS-FBG filters designed for the wavelengths 1550 nm to 1555 nm and the corresponding frequency of oscillation was observed between 4.63 GHz and 40.17 GHz. We make observations of the oscillating frequency. With the help of simulated results, the overall model has been theoretically analyzed and verified.