laser – Page 2 – Yan Feng

Breakthrough in guide star laser development

The Messenger is a quarterly journal presenting ESO‘s activities to the public. It has rather wide readership in the astronomy community. In the 2010 March issue, we have an article summarizing the development of Raman fiber amplifier based guide star laser at ESO.

Laser Development for Sodium Laser Guide Stars at ESO

Bonaccini Calia, D.; Feng, Y.; Hackenberg, W.; Holzlöhner, R.; Taylor, L.; Lewis, S.

Abstract: A breakthrough in the development of sodium laser guide star technology at ESO was made in 2009. The laser research and development programme has led to the implementation of a narrowband Raman fibre laser emitting at the wavelength of the sodium lines at 589 nm with demonstrated power beyond 50 W. Fibre lasers are rugged and reliable, making them promising candidates for use in the next generation of laser guide star systems, such as the Adaptive Optics Facility planned for installation on VLT UT4 in 2013.

The full article can be downloaded here.

150 W highly-efficient Raman fiber laser

A new paper is out. Yan Feng, Luke R. Taylor, and Domenico Bonaccini Calia, “150 W highly-efficient Raman fiber laser,” Opt. Express 17, 23678-23683 (2009).

We report a more than 150 W spectrally-clean continuous wave Raman fiber laser at 1120 nm with an optical efficiency of 85%. A ~30 m standard single mode silica fiber is used as Raman gain fiber to avoid second Stokes emission. A spectrally asymmetric resonator (in the sense of mirror reflection bandwidth) with usual fiber Bragg gratings is designed to minimize the laser power lost into the unwanted direction, even when the effective reflectivity of the rear fiber Bragg grating becomes as low as 81.5%.

That is the laser we built to pump the 39 W narrow linewidth 1178 nm Raman fiber amplifier.