Hannover 2010 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

Q: Fachverband Quantenoptik und Photonik

Q 55: Poster II

Q 55.70: Poster

Thursday, March 11, 2010, 16:00–19:00, Lichthof

Tunable upconversion Pr,Yb:ZBLAN fiber laser from 601 nm to 625 nm — •Benjamin Hermberg, Ortwin Hellmig, Klaus Sengstock, and Valeri Baev — Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg

Compact coherent light sources at different wavelengths in the visible can be realized with an upconvertion Pr/Yb-doped ZBLAN fiber laser. Selective dielectric mirrors placed to both ends of the fiber are usually used for the selection of the required emission wavelength, e.g. 492, 520, 535, 605, 612, 635, or 717 nm. Since the separation between some of the emission lines is smaller than the spectral broadening of the gain, continuous wavelength tuning between neighboring transitions is possible [1]. We have realized a broadband spectral tuning between 605, 612 and 635 nm transitions with a specially designed nonuniform narrowband spectral filter placed in the open part of the cavity. A spectral filter made out of 19 dielectric layers is highly transparent at the desired wavelength and highly reflecting at small detunings. This requirement is very important because of strong variations of the laser gain. An additional 50% cavity loss is achieved at 0.5 nm detuning. Transmission maximum of the filter can be spectrally shifted over 50 nm by its translation perpendicular to the optical axis. The tuning range demonstrated in this experiment extends from 601 to 625 nm, which is 3 times larger than the tuning achieved with a Bragg grating [1].

1. M Zeller, H. G. Limberger, and T. Lasser, IEEE Photonics Technology Letters 15, 194 (2003).