Photonic fan-out and local selectable inversion of the optical hysteresis shape

We demonstrate and elucidate the local selectable inversion of the hysteresis shape of a bistable optical signal after fan-out. This selectability is based on a hysteresis-shape transformation that yields a switching contrast over 20 dB in magnitude for both the inversion clockwise (CW) and the non-inversion counterclockwise (CCW) hysteresis shapes, while maintaining input-switching powers. This behavior leverages an initial signal whose bistability is manifested by its state of polarization; a generalized Malus' law elucidates how selection is possible by controlling the transmittivity hysteresis through each local polarizer. The concept is demonstrated using a Fabry-Perot semiconductor optical amplifier to produce the initial bistable polarization-rotating signal, followed by a 1X2 fan-out and the realization of all four hysteresis shapes at each location, independent of the other location. This fan-out and selectable inversion behavior is applicable to other nonlinear photonic systems and provides new functionality for parallel optical processing.