  We theoretically study analytic-phase synchronization in strongly-competing
oscillator systems. Using the example of composite-cavity modes coupled via a
class-B laser active medium, we discover that inherent chaotic phase
synchronization can arise concurrently at two different chaotic attractors,
leading to bistable phase-synchronized solutions. In our example, the
underlying mechanism for bistability and inherent phase synchronization is
population pulsation within the active medium.
