Speaker: Dr Thomas Südmeyer, ETH Zurich
Date: 23 June 2010
Time: 2pm
Venue: B46 LT B
Abstract:
One of the major technology trends in laser research is the progress of ultrafast laser sources from complicated laboratory systems towards compact and reliable instruments. SESAM-modelocked ultrafast lasers using the thin disk geometry are a promising technology for this task.
The first part of the presentation focuses on femtosecond ion-doped solid-state thin disk lasers, which recently exceeded pulse energies above 10 µJ at multi-megahertz repetition rates and average power levels >140 W. With this development, many applications that previously relied on complex and expensive amplifier systems are now within reach of simple and cost-efficient laser oscillators. The high average output power bears a considerable potential for reducing processing speeds and increasing throughput in material processing applications.
The second part focuses on ultrafast vertical external cavity surface-emitting lasers (VECSELs), which are semiconductor lasers using the thin disk laser geometry. Ultrafast VECSELs access a different operation regime than ion-doped solid-state thin disk lasers, generating pulse energies in the pico- to nanojoule regime, but with repetition rates in the gigahertz range. They have a number of compelling advantages, including power scaling and their ability to access wavelengths regions that are not easily accessible with established ion-doped solid-state laser materials. Such performance in combination with the potential for cost-efficient mass production makes these lasers a promising alternative for many applications, which currently rely on more bulky and expensive laser systems. We present an overview on the current state-of-the-art and discuss a further integration step towards compact and low-cost ultrafast lasers, which we refer to as the modelocked integrated external-cavity surface emitting laser (MIXSEL). MIXSELs achieve more than 4 W average output power, which is higher than any other modelocked semiconductor laser. Such devices appear highly attractive for numerous large-scale applications such as optical clocking of multi-core microprocessors, frequency metrology, biomedical imaging, or telecommunication.