  An optoelectronic oscillation method with reconfigurable multiple formats for
simultaneous generation of coherent dual-band signals is proposed and
experimentally demonstrated. By introducing a compatible filtering mechanism
based on stimulated Brillouin scattering (SBS) effect into a typical
Phase-shifted grating Bragg fiber (PS-FBG) notch filtering cavity, dual
mode-selection mechanisms which have independent frequency and time tuning
mechanism can be constructed. By regulating three controllers, the proposed
scheme can work in different states, named mode 1, mode 2 and mode 3. At mode 1
state, a dual single-frequency hopping signals is achieved with 50 ns hopping
speed and flexible central frequency and pulse duration ratio. The mode 2 state
is realized by applying the Fourier domain mode-locked (FDML) technology into
the proposed optoelectrical oscillator, in which dual coherent pulsed
single-frequency signal and broadband signal is generated simultaneously. The
adjustability of the time duration of the single-frequency signal and the
bandwidth of the broadband signal are shown and discussed. The mode 3 state is
a dual broadband signal generator which is realized by injecting a triangular
wave into the signal laser. The detection performance of the generated
broadband signals has also been evaluated by the pulse compression and the
phase noise figure. The proposed method may provide a multifunctional radar
system signal generator based on the simply external controllers, which can
realize low-phase-noise or multifunctional detection with high resolution
imaging ability, especially in a complex interference environment.
