A 5λ-thick hybrid semiconductor/dielectric GaN-based microcavity grown by metal-organic chemical vapor deposition on a c-plane bulk GaN substrate was investigated using angle-resolved photoluminescence and angle-resolved cathodoluminescence techniques at room and low temperature (5.8 K), respectively. The cavity structure consisted of an InGaN multiple quantum well active region emitting at 400 nm and sandwiched between 29.5 pair bottom semiconductor AlN/GaN and 13.5 pair top dielectric SiO<sub>2</sub>/SiN<sub>x</sub> distributed Bragg reflectors. The cavity supported strong exciton-photon coupling with a record 75 meV vacuum Rabi splitting energy at 5.8 K. The measured room temperature Rabi splitting energy of 45 meV is still close to the highest Rabi splitting energies reported in literature confirming that the strong coupling regime still persists at room temperature.
High-brightness fiber coupled laser modules are presented with output powers of more than 75W and electro optical
efficiencies of more than 45%. An ongoing lifetime test shows nearly 3000h reliable operation. A wavelength
stabilization using external gratings is shown with stable wavelength locking over a large temperature range. To combine
the output powers of the fiber coupled modules fiber combiners were used and powers in the 400 and 1000W range were
achieved for output fibers of 200 and 400μm, respectively.
Lasers for marking, direct application laser systems as well as high power solid state lasers require highly reliable, high
efficient and low cost laser diodes. Especially fiber lasers and direct diode systems have additionally the need for high
brightness. For a very long time either single emitter solutions with low brightness and costs or beam shaped bar
solutions with high brightness and high costs served those needs. Since roughly 2 years multiple single emitter solution
are more and more penetrating the market showing a high potential for serving all needs of a broad customer base.
Based on the 50W product introduced by the middle of 2009 we would like to show the design which is based on
qualified and highly stable single emitters.