Rod-type fiber laser reaches new nanosecond pulse-power heights

Engineers and scientists at Femlight (Talence, France) and the University of Jena (Jena, Germany) have created a rod-type fiber laser with a very large core and short length that overcomes the limits of conventional fiber lasers and diode-pumped solid-state (DPSS) rod lasers for short-pulse generation. Although DPSS lasers can produce energetic pulses, their beam quality degrades when the average power increases; fiber lasers can produce very high average powers with a diffraction-limited beam but do not sustain the pulse energy needed for industrial applications where short pulses are used, such as flat-panel-display patterning and deep engraving.

Using a 60-cm length of microstructured fiber, the Femlight group demonstrated a 280-kW-peak-power Q-switched laser with 8.5-ns, 2.4-mJ pulses at a wavelength of 1030 nm and repetition rates adjustable from 1 to 100 kHz. The patent-pending diode-pumped fiber laser provided average powers up to 100 W in a diffraction-limited polarized beam with 41% optical-to-optical efficiency; the 60-µm-diameter fiber core intrinsically supported single-mode operation. “We expect the average power to reach 200 W in 2006 and 1 kW in the following years,” says François Salin, Femlight’s chief technical officer. Contact Salin at [email protected].