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Research News

In the past five years…

It is already five years that I blogged nothing here. Just give a short outlines here to show the main research achievements.

We have improved and maturized the Raman fiber amplifier based guide star lasers. The laser can now operate at CW, 100 microsecond quasi-CW, and pulsed at Larmor frequency. Laser prototypes were tested at telescopes for sodium guide star, and also for mesospheric magnetometry.

With cascaded random Raman fiber laser, we have demonstrated up to 11 th Raman Stokes light generation. With a Yb pump laser at 1 micron, continuous wavelength tuning up to 2 micron were demonstrated. With this technology, fiber lasers can now output more than 100 W at any wavelength from 1030 nm to 2000 nm.

We continued our study on mode locked Raman fiber lasers, have made some interesting demonstrations including NPR mode locked dissipative soliton, figure of 8 dissipative soliton, rectangular pulse generation etc. We believe we have improved the understanding of mode locked Raman fiber lasers now.

Amplified spontanesou emission sources were found to be useful for pumping cascaded random Raman fiber lasers and mode locked Raman fiber lasers.

Specialty lasers at various wavelengths were demonstrated with wavelength tuning of fiber lasers and second harmonic generations.

Besides, we have made contributions in scattered topics. Many of them are actually more interesting and look for futher developments. Check out our publication list.

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Research News

Update in 2013

In 2013, we continued our studies on Raman fiber laser/amplifier and mode locked fiber laser, and development of lasers for guide star and cold atom physics.

We found a method for power scaling of single mode linearly polarized Raman fiber laser. In a proof of principle experiment, an output power of 300 W has been achieved, limited by available power. In the single frequency Raman fiber amplifier direction, we have achieved more than 80 W at 1178 nm in the CW case and more than 120 W in the QCW long pulse case. Consequently, after frequency doubling, more than 50 W CW and 80 W QCW (peak power) laser at 589 nm have been demonstrated. With these results, we are confident that power scaling of Raman fiber amplifier based guide star laser to over 100 W is feasible.

We are always interested in applying our expertise in wavelength flexible high power narrow linewidth fiber amplifier to atomic physics. In this year, we have scale the room temperature 1014.8 nm single frequency fiber amplifier to ~ 20 W, and carried out the frequency doubling and quadrupling experiment to 253.7 nm, and absorption and Doppler-free absorption spectral measurement of mercury atoms.

Together with Prof. Gu of Ryerson University, we also studied mode locked Yb fiber lasers with chirped FBGs, and demonstrated dual wavelength switchable dissipative soliton fiber laser and studied the effect of large normal and anomalous dispersion.