Collaborative Research Center Sfb 787 „Semiconductor NanoPhotonics“

At the beginning of 2008, the Collaborative Research Center (Sonderforschungsbereich) 787 "Semiconductor NanoPhotonics: Materials, Models, Devices" was launched, researching novel photonic devices, nanomaterials and mathematical models in the field of nanophotonics. In 2016, the third funding period started with more than € 11 million provided by the German Research Foundation (DFG) up to 2019. The total funding (2008-2019) is about € 35 million. The Collaborative Research Center Sfb 787 supports more than 140 scientists from Berlin and Magdeburg, among them more than 70 students from the newly established Postgraduate School of Nanophotonics.

The FBH is currently involved in projects C9 and A7 within the Sfb: In project C9, AlGaN-based laser diodes emitting in the far ultraviolet spectral region are realized. This goal shall be achieved in three steps: the realization of optically pumped (In)AlGaN lasers in the UV-C wavelength range, investigation of electroluminescence and optical gain in (In)AlGaN MQW laser heterostructures, and the demonstration of injection laser diodes for wavelengths < 280 nm. This project is an important building block for the activities within the Joint Lab GaN Optoelectronics at the institute, a joint initiative of FBH and TU Berlin. In project A7, the group of U. Woggon at TU Berlin investigates the dynamic behavior in quantum dot and quantum wells with pump probe spectroscopy. The FBH fabricates the corresponding laser diodes and amplifiers with these gain media.

Completed projects

Three projects were successfully completed at FBH. Within project A1 (2011) FBH realized highly efficient InGaN nanomaterials and demonstrated high-power GaN-based laser diodes in the blue and green spectral range. Project C5 (2011) explored semiconductor laser structures that enable extremely small beam divergence (< 7°) and new approaches for wavelength stabilization. Project C6 (2015) aimed at laser diodes for two different applications that required adapted device layouts. The first is high bit rate telecommunication at and beyond 100 Gbit/s, including studies of multi-section laser diodes with mode-locking and corresponding D(Q)PSK transmission experiments. The know-how on mode-locking was then combined with high brightness and high transverse fundamental mode output power obtained with Photonic Band Gap Lasers (PBCLs) to realize mode-locked laser with short pulses and very high peak output power for direct application in materials processing – the second targeted application.