Increased demand for high-quality glass cutting and processing, drives the adoption of femtosecond lasers. Many applications within micromachining demand both high pulse energies and average power to handle a wide range of materials and processes at high throughput.
The high-power ultrashort laser pulse can vaporize glass with almost no heat conduction in a cold ablation process that leaves a perfect edge without any thermal damage or micro-cracks, as typically seen with long-pulse lasers.
Motivated by these demands, we have worked on further power-scaling our unique aeroGAIN-ROD PCF platform and have managed to increase the average power handling by 2.5 times.
To test the capabilities of the next-generation aeroGAIN-ROD PCF technology, we built a fiber-based chirped-pulse-amplification laser system. Now we can share key performance metrics such as mode-quality, temporal pulse characteristics, Thermal Mode Instability (TMI) level, and power level monitored across more than 4000 hours of accumulated runtime.
In the setup, we achieved:
- An average power of 175 W (248 W at ROD output)
- A pulse duration of 357 fs, with 233 µJ pulse energy at a 750 kHz repetition rate
- A beam quality factor, M2, of 1.21 after re-compression (M2 of 1.04 at ROD output)
Get all the details in the publication
Read the publication “175 W average power from a single-core rod fiber-based chirped-pulse-amplification system” in Optics Letters, vol. 47, issue 19, 2022, or fast forward to the conclusion:
“We have demonstrated a single-core rod fiber-based CPA system delivering 357 fs pulses at 1030 nm with a repetition rate of 750 kHz, 175 W average power, 233 µJ pulse energy, and an M2 of 1.21.
We have shown that the long-term effects on a state-of-the-art single-mode photonic crystal rod-type ytterbium-doped fiber do not give rise to any increase of TMI due to photo-darkening, which makes it possible to operate the amplifier at 248 W average power for more than 4000 hours free of TMI.
This demonstrates that large core photonic crystal fibers are a suitable technology to realize laser systems with near diffraction-limited output beam quality delivering ultrashort pulses with an energy of hundreds of µJ at near-MHz repetition rates.
Development in the thermal management and scaling of fiber core size will provide a route for further power scaling.”