Prof. Rainer Martini

Main research that I am interested in:

Direct all-optical modulation of laser and detectors: The optical electrical conversion of information at each communication is one of the major bottlenecks in communication technology. In our laboratory we use direct optical modulation of lasers and detectors to achieve an all-optical and hence ultrafast wavelength converter – and in turn multiplexer and de-multiplexer devices. Within the last years we have proven the direct optical amplitude modulation of mid-infrared Quantum Cascade Lasers up to a frequency of 7 GHz – limited only by detector speed.

New form of optical modulation: Aside from the expected amplitude modulation, we achieved a fast (2GHz) frequency modulation. This gives rise to a direct optical FM modulation of lasers and hence allowing more robust and stable data transmission. Possible additional features are the simultaneous modulation via optical and electrical means, which would allow for higher level modulation such as phase modulation, QPSK, and QAM.

Novel techniques in Free-Space Optical communication: The application of yet unused spectral wavelength like the Mid- and Far- Infrared spectrum is one of the core research areas in our laboratory.

New form of Infrared Imaging Devices and their application: Mid- and Far-Infrared Imaging devices have become popular in multiple areas reaching from security aspects to medical diagnostics and material inspections. Within our laboratory new wavelength conversion techniques are applied to allow for simpler but more powerful imaging concepts towards an easier access to this specific section of the spectrum. One of the most recent devices was able to observe and measure beam profiles ranging from 400nm (UV) down to 110 GHz, covering the whole range from UV, Vis, NIR, MIR, FIR, to RF.