Projekt - QuantumCascade

The objective of the QuantumCascade project is the design of a multispectrum MIR light source as an easily integrated system component for use in applications that work with mid-infrared light. The system should be usable without requiring particular knowledge of the complex technology behind multispectrum light sources. This makes it available for commercial enterprises from other fields, e.g. medical technology, facilitating the development of innovative systems without the risk of having to design a stable and controlled light source of this type.
The multispectrum MIR light source or MIR engine combines the following innovations:

  • Modular use with a selection of individually combinable QCLs / spectral lines
  • Integrated and automatic temperature controls for the individual QCLs for the stabilization or fine adjustment (sweeping) of wavelengths
  • Novel packaging concept for controlling the temperature of the QCL chips placed in immediate proximity to each other (formation of heat-stabilizing cavities in a glass stack)
  • Embedding of laser drivers adjacent to the QCLs to achieve low inductivity / top pulse quality and modularity
  • Integrated control circuits to automatically regulate the MIR engine for top performance without additional electronics needed for operating the light sources when integrated in the final applications
  • Encapsulation concept for the entire MIR engine for use in rugged environments and to allow disinfection in critical medical applications
  • Significant miniaturization of the MIR engine with a free beam or a fiberoptical bus

In the interest of greater integration, the new developments are based on a thin-glass platform that has already been in use at IZM for several for the construction of hybrid systems that can integrate and efficiently couple a diverse range of optical and electronic components.

The design of the final MIR engine 3

A cascade of three separate QCL MIR sources for pulsed / sweeping operation, optical beam combining / fiber coupling in a closed package. Approximate size: 80 mm x 100 mm

© Fraunhofer IZM

QCL: Quantum Cascade Laser:

Special epitaxially constructed semiconductor chips with an edge emitter, used for:

Emitting light in a wavelength range of approx. 2 to 15 µm in the MIR (mid-infrared spectrum) – depending on the wavelength set for the QCL design


  • Laser Electronics LE GmbH (Adlershof)