Non-linear phototedector based on single atomic layer graphene.

Single atomic layer graphene-based devices

In recent years, graphene has reveald a multitude of interesting physics. Our group is particularly interested in the ultrafast optical properties of this novel material. We produce large area, high-quality single-layer graphene films by chemical vapor deposition on copper. We are currently working on a variety of different optical devices with interesting ultrafast optical and electrical properties. More...
 

Chip-scale mode-locked lasers

Mode-locked lasers producing ultrashort pulses have revolutionized a variety of disciplines in applied optics and fundamental science. For the first time such lasers not only enable to time-resolve processes with femtosecond resolution (1fs = 10-15s) but they also enabled us to engineer electromagnetic waveforms at hundreds of THz. In this project we are working towards fully integrated mode-locked sources that ultimately allow the production of quantum-noise limited optical pulse-trains. Such sources will empower a huge pool of applications in various scientific disciplines. More...

Spectrum of molecular iodine measured in a single sweep with an absolute-frequency stabilized cw-laser.

Novel applications of optical combs

As an interesting by-product, modelocked lasers produce an ultra-precise comb-like optical spectrum. Such optical spectra can be stabilized actively to produce what is known as optical frequency combs (Nobel prize in Physics 2005.) Such optical combs have found applications primarily in precision optical metrology. Here, we demonstrate and develop novel applications of such combs with emphasis on environmental monitoring, biology and medical applications.
 

Ultra high-Q optical microresonators

Optical microresonators with Q-factors exceeding  10⁹ are very promising widgets for a large variety of applications in precision spectroscopy, sensing and fundamental sciences, such as for cavity QED experiments. Here we explore novel methods to reliably produce such resonators and put them to work in a variety of applications in fundamental and applied sciences. More...