Volker Hagemann

OLED devices for signage applications: a review of recent advances and remaining challenges

Reported efficiency records of >70 lm/W and the communitys performance roadmaps indicate the potential of OLEDs (Organic Light Emitting Diodes) for use in general lighting applications. Within a shorter timeframe, OLED technology may be exploited for signage applications. Key differences of OLED signage devices to display and lighting devices are discussed. Recent results are presented on large area device design, polymer deposition technology, device and material performance, and encapsulation technology. Finally we discuss performance and cost targets for potential applications indicating the main challenges for future developments.

New heavy metal oxide silicate amplifier glass for compact and broadband amplifiers

Properties of a new rare-earth doped heavy metal oxide containing silicate glass are presented. The glass has potential for fabrication of ultra-short wideband fiber and planar waveguide amplifiers. We report specific results for a fiber amplifier geometry, discussing achieved improvements in device compactness (Giles gain g* = 210 dB/m allowing up to 100 times shorter fiber) and amplification bandwidth (50% more bandwidth in C-/L-band) compared to the conventional EDFA. We also access the potential of this material for fabrication of active planar integrated waveguide devices.