抄録
We have developed high-peak and high-average-power polarization-maintained Yb doped PCF (Photonic
Crystal Fiber) rod-fiber laser system. When the main 85 μm-PCF rod amplifier was seeded with 40 W,
maximum average output power of over 210 W (pulse width: 10 ns, energy: 0.2 mJ at 1 MHz) and an
excellent beam quality M2 of 1.3 was obtained. Total average power at one wavelength (four beams) was
obtained to be 700~800 W. In the final fiber laser system designed for material processing applications,
three units, each consisting of four coherently combined beams with over 400 W of total power, were
constructed. In the final stage, output beams of those three units (1035, 1040 and 1045 nm) were
combined by tiled-aperture beam combination technique, delivering more than 1.4 kW average output
power at high repetition rates (75 kHz-5 MHz) with few 100 picoseconds to few10 nanoseconds pulse
duration.
