Optimum configuration of multiloop optoelectronic oscillators

Multi-cavity optoelectronic oscillators using multicore fibers

“…Finally, multi-cavity or multiloop OEOs have been proposed [21], where a long cavity provides the required spectral purity and a short fiber cavity provides the required spectral separation between adjacent oscillating modes, what alleviates the narrowband requirement for the internal RF filter. Furthermore, these structures can be generalized to an arbitrary number of loops and its design optimized for cavity lengths that are multiple of a given reference value [22].…”

“…In section 2 we extend the theory developed in [21,22] for the case of two cavity OEOs to a general number N of cavities providing the equations describing the oscillation spectrum, amplitude and phase oscillation conditions, and phase noise spectrum. We describe in section 3 the proposed configurations based on homogeneous MCFs, where we consider two separate cases: a first one corresponding to two (short and long) unbalanced cavities, as reported in [21] and optimized in [22]; and a second one related to N almost equal length cavities working under the vernier configuration [23]. In section 4 we analyze a configuration based on a heterogeneous MCF, showing as well that this particular scheme allows tunability of the oscillation frequency by operating the OEO with a tunable laser.…”

Microwave Signal Processing over Multicore Fiber

“…Multicavity or multiloop optoelectronic oscillators [53][54][55][56][57] can benefit from a reduction of size and weight if the different cores of a multicore fiber act as the required oscillation cavities. In addition, since all the cavities are hosted within the same cladding, this approach provides a fiber integrated medium for enhancing the OEO relative stability against environmental and mechanical fluctuations.…”

“…In essence, a short loop provides the required spectral separation between adjacent oscillating modes while a long loop is responsible for the spectral purity. The number of loops can as well be generalized to an arbitrary number [54][55][56][57]59]. In concrete, the work reported in [54] experimentally demonstrated three-cavity OEOs by using three different single-mode fiber links whose lengths were multiple of a given reference value.…”

“…The number of loops can as well be generalized to an arbitrary number [54][55][56][57]59]. In concrete, the work reported in [54] experimentally demonstrated three-cavity OEOs by using three different single-mode fiber links whose lengths were multiple of a given reference value. The incorporation of MCFs as the hosting medium for all the cavities was first proposed and theoretically evaluated in [55] considering both homogeneous and heterogeneous fiber configurations.…”