Multicore fiber distributed feedback lasers.

We demonstrate parallel fabrication of seven fiber distributed feedback (DFB) lasers in a hexagonally arrayed multicore core Er doped fiber with 40 μm core spacing. DFB grating cavities 8 cm long and operating near 1545 nm were fabricated with a single UV inscription exposure. We observed dual polarization, single longitudinal mode operation with a linewidth below 300 kHz for each laser.