Microwave photonic signal generation using a quadratic FBG based optoelectronic oscillator

Abstract We proposed an optoelectronic oscillator (OEO), incorporating a dual parallel Mach-Zehnder modulator (DP-MZM) and quadratic fiber Bragg grating (QFBG) for microwave photonic (MWP) applications. The suggested system combines the unique dispersive and reflective properties of the QFBG to achieve enhanced frequency stability and spectral purity. The QFBG facilitates precise control over the oscillation frequency by introducing quadratic phase modulation, effectively suppressing spurious modes and improving phase noise performance. Experimental results demonstrate the capability of the OEO-QFBG system to generate low-phase-noise microwave signals with superior stability compared to conventional OEO designs. A 20 GHz microwave signal with low phase noise of –134.93 dBc/Hz at 10 kHz offset was generated. This work underscores the potential of integrating advanced photonic components, such as QFBGs, for advanced microwave photonics applications, including radar systems, communications, and high-precision instrumentation.