ABSTRACT
We demonstrate that it is possible to pump an Ng-cut Yb:KGW crystal slab with up to 18W by a single emitter laser diode and still achieve a nearly diffraction limited output beam with a M(2) value below M(2) < 1.1 and optical to optical efficiencies of more than 44%. Furthermore, we have measured the focal length of thermally induced lenses in an Yb:KGW crystal slab which was end-pumped by 12 W and 18 W single-emitter diodes. We have observed that the focal lengths not only depend on the pump power and beam waists, but are also dependent on the specific diode beam profile, as well as the collimation optics. We have been able to correlate this behavior with specific patterns of the beam profile.
Subject(s)
Lasers , Lenses , Temperature , Ytterbium/chemistry , Finite Element AnalysisABSTRACT
We have realized a 76 MHz white-light differential transmission spectroscopy system. The technique employs a Ti:sapphire laser oscillator and a tapered fiber to generate a white-light continuum spanning almost the full visible to near-infrared spectral range. Using acousto-optical modulation and subsequent lock-in detection, transient relative transmission changes as small as 10(-5) are detected. The method is applied to study the ultrafast gain dynamics of the active layer of a vertical-external-cavity surface-emitting laser based on a multiple-quantum-well structure.
ABSTRACT
We demonstrate a new and extremely compact design for a directly diode-pumped Yb:glass laser oscillator that is used as femtosecond light source for supercontinuum generation. The laser is capable of generating femtosecond pulses of 150 fs and pulse energies up to 39 nJ at a repetition rate of 20 MHz. By using a Herriott-type multi-pass cell, 70 % of the total resonator length are folded to only 30 cm. With off-the-shelf components, our setup has a footprint of 62x23 cm(2). Using smaller mechanical components, the size can easily be further decreased. In combination with a tapered fiber, the laser forms a cheap, stable, and compact femtosecond supercontinuum source with up to 400 mW of average whitelight power.
