Optoelectronic Devices

Quantum cascade lasers

We currently focus on the following developments:

• Improving the output power and performance efficiency
• Preservation of the beam quality
• Optimization of the epitaxial semiconductor layer structure
• Efficient cooling of components via improved packaging technology

Optically pumped semiconductor disk lasers

Experts of Fraunhofer IAF conduct research on the basis of group III antimonides in order to extend the functionality of semiconductor lasers. An example is the integration of chips in external resonators in the form of compact laser modules for spectrally fast tunable laser systems.

Applications:

• spectroscopic sensors – real-time detection of solid substances
• medical applications
• safety applications – stand-off detection of hazardous substances

Infrared detectors

Matrix and single detectors of highest performance:

• InAs/GaSb type II superlattices for the mid- (MWIR, 3 – 5 µm) and long-wave infrared (LWIR, 8 – 12 µm)
• InGaAs for the short-wave infrared (SWIR, < 1.7 µm)
• AlGaN for the solar blind ultraviolet regime (< 280 nm)

Devices using heterojunctions are being developed in order to improve the performance. These have significant advantages over commonly used homojunction devices, particularly in the field of dark current and noise behavior.

Avalanche photodiodes

We develop highly sensitive avalanche photodiodes (APDs) with integrated signal amplification for applications that require the detection of very weak optical signals.

We do this for the solar-blind ultraviolet spectrum below 280 nn as well as for the short-wave infrared (SWIR, 0,9 – 1,7 µm), for which we optimize AlGaN and InGaAs APDs.