Overview Tutorial Jan. 2020

Tutorial on short pulse generation with VECSELs and MIXSELs

Invited Presentation at Photonics West 2020

A detailed overview about ultrafast and cw semiconductor disk lasers (SDLs) is given in recent review papers [1,2]. We have observed a rapidly developing field of optically- and electrically-pumped VECSELs. These lasers have been successfully commercialized and have gained a strong interest for power scaling with optical pumping. In a VECSEL, the light is emitted perpendicular to the epitaxial layers, unlike edge-emitting lasers, where the beam propagates in the epitaxial layers. In contrast to a VCSEL (i.e. a Vertical Cavity Surface Emitting Laser), the external cavity of the VECSEL offers additional mode control for excellent transverse beam quality even at highest power levels and enables the integration of elements for nonlinear intracavity frequency conversion, wavelength tuning elements, passive modelocking with a semiconductor saturable absorber mirror (SESAM) and dual-comb generation. For the MIXSEL the SESAM is integrated within the same layer stack as the gain. The MIXSEL then generates a modelocked pulse train from a simple linear straight cavity defined by the MIXSEL chip and the output coupler as the two end mirrors. An additional intracavity birefringent plate then enable dual-comb generation with an adjustable difference in the individual comb spacing. No active stabilization is required for dual-comb spectroscopy.

[1] M. Guina, A. Rantamäki, A. Härkönen, "Optically pumped VECSELs: review of technology and progress". J. Phys. D: Appl. Phys. 50, 383001 (2017)

[2] B. W. Tilma, M. Mangold, C. A. Zaugg, S. M. Link, D. Waldburger, A. Klenner, A. S. Mayer, E. Gini, M. Golling, U. Keller, Download"Recent advances in ultrafast semiconductor disk lasers" (PDF, 2 MB)vertical_align_bottom. Light Sci Appl 4, e310 (2015).

This tutorial talk explains the the single and dual-comb pulse generation with these semiconductor disk lasers.

Download PDF Tutorial talk Downloadhere (PDF, 10.1 MB)vertical_align_bottom.