  We present a coherently-combined femtosecond fiber CPA system based on a
rod-type, Ytterbium-doped, multicore fiber with 4x4 cores. A high average power
of up to 500 W (after combination and compression) could be achieved at 10 MHz
repetition rate with an excellent beam quality. Additionally, <500 fs pulses
with up to 600 uJ of pulse energy were also realized with this setup. This
architecture is intrinsically power scalable by increasing the number of cores
in the fiber.
