DFB laser contribution to phase noise in an optoelectronic microwave oscillator

The optoelectronic fiber delay line microwave oscillator offers attractive and large potential for numerous applications in high speed fiber optics communication, space, and radar systems. Its relevant features are very low phase noise and wide-range tunability, while operating at frequencies of tens of GHz. We consider the contribution of the DFB laser to the oscillator phase noise. Low frequency spectra of wavelength fluctuation and RIN are measured and analyzed. As a conclusion, the oscillator phase noise can be improved by proper choice of optic and optoelectronic components.