Compact ultrafast waveguide lasers for frequency comb

key members:

Optical frequency combs act as extremely accurate rulers in the frequency domain and provide a phase-stable link between microwave and optical frequencies. Their invention revolutionized various fields in metrology and was honored by the 2005 Nobel Prize in Physics. Ultrafast dielectric waveguide lasers are one of the most promising technologies for compact ultrastable frequency comb generation. These lasers combine advantages of ion-doped solid-state and semiconductor lasers, achieving high output powers with excellent beam quality and enabling a wafer-scale production with a high level of integration. In addition, the high mechanical stability enables low-noise operation with low timing jitter.

In this project, we target the realization of modelocked waveguide lasers with record-high peak power and want to explore their suitability for octave-spanning supercontinuum generation and frequency comb metrology. To reach this target, multiple waveguide technologies (Figure 1) are used through different collaborations: Yb-doped glass ion-exchanged waveguides in collaboration with IMEP-Grenoble (France), Yb-doped KGW micro-structured waveguides in collaboration with University of Twente (The Netherlands) and Yb-doped YAG femtosecond written waveguides in collaboration with Institut für Laserphysik – Hamburg (Germany). To achieve mode-locking of these gain materials, Semiconductor Saturable Absorber Mirrors (SESAM), dye saturable absorber, carbon nanotubes and graphene will be used in this project.

The final goal is to generate self-referenced frequency combs using a fully integrated device enabling high compactness and wafer scaled devices production.

 Illustration of integrated waveguides

Figure 1: Illustration of integrated waveguides using (1) glass ion-exchange (made at IMEP – Grenoble), (2) KGW micro machining (made at university of Twente) and (3) YAG femtosecond written (made at Institut für Laserphysik – Hamburg).