Single-mode 60μm-core multiple-cladding-resonance photonic bandgap fiber laser with ∼1kW output power

We report the effectiveness of multiple-cladding-resonance photonic bandgap fiber for suppressing mode instability by demonstrating pump-limited single-mode output power of ∼1kW in a 60μm-core fiber, a record for any fiber lasers at this core diameter.