Fraunhofer Institute for Applied Optics and Precision Engineering IOF

The Fraunhofer Institute for Applied Optics and Precision Engineering IOF is presenting a new photon source at SPIE Photonics West in San Francisco (January 28 to 30, 2025) that has been specially developed for the "Prepare-and-Measure" protocol of quantum communication. The components of the source are optimized for use in space. The concept of using strongly attenuated, randomly polarized light pulses for secure quantum communication has been around since the mid-1980s. Most commercial light sources for quantum communication are still based on this idea today. The biggest challenge here is to generate indistinguishable and randomly polarized photons at a high rate in a source that is as compact and energy-efficient as possible. Fraunhofer IOF in Jena has now developed a photon source based on a linear array of eight semiconductor lasers (VCSELs). It has a ultra-compact design, high spectral and temporal precision and good polarization quality. The system has been specially developed for secure connections from satellites to the ground station. The Fraunhofer IOF team will present a prototype of the photon source for secure quantum communication at this year's SPIE Photonics West in San Francisco (USA) from January 28 to 30 at the Fraunhofer booth in the German Pavilion (4205 North Hall). Erik Beckert, head of the "Opto-mechatronic Components and Systems" department at Fraunhofer IOF, will present the technology on January 26 at 1:50 p.m. (Room 158, Moscone South) in his lecture "Ultracompact, VCSEL-based photon source for prepare-and-measure QKD".