Semiconductor Lasers

Fraunhofer IAF develops III-V semiconductor lasers and components for applications in sensor technology, communications, and measurement and medical technology. The institute not only handles component design and manufacturing but also builds modules and systems using components with unique properties.

We support you throughout the entire value chain: specifically through tailored epitaxy and technology developments, the creation of automatable manufacturing routines for laser modules requiring active alignment, and the production of small batches. 

Optically pumped semiconductor disk lasers

• Emission range: 1,9–2,8 µm
• Class A laser with precisely tunable emission wavelength
  • Ideal pump source for solid-state lasers inside and outside resonators as well as for non-linear optical crystals

Quantum cascade laser

• Wavelength range: 4–12 µm
• Scan frequency up to 1 kHz
• Broadly tunable
• Compact and combinable modules

Optically pumped semiconductor disk lasers as extremely narrow-band, low-noise pump lasers

The optically pumped GaSb-based semiconductor disk lasers (SDLs) for the 1.9–2.8 µm spectral range developed by Fraunhofer IAF are characterized by outstanding beam quality, high output power, and stable, low-noise laser emission. They set global standards in terms of output power, linewidth, and absolute frequency stability—qualities required, for example, for the pump source in single-photon quantum frequency conversion.

Quantum Cascade Lasers for Infrared Spectroscopy

The Fraunhofer IAF is developing quantum cascade lasers for the mid-infrared range of 4–12 µm. By combining these broadband QCL chips with MEMS grating scanners—which were developed in collaboration with Fraunhofer IPMS and are used to tune the emission wavelength in an external optical resonator—it has been possible to create particularly compact laser modules with unique properties. Fraunhofer IAF is a leader in combining multiple such sources into an extremely broadband and highly agile laser source that enables infrared spectroscopy at kilohertz rates.

AlGaAs Bragg reflection waveguides as chip-based source for entangled photon pairs in the telecom C-band 

AlGaAs Bragg reflection waveguides are promising systems for generating single and entangled photons in the telecom C-band at 1550 nm via the process of spontaneous parametric down-conversion (SPDC). In the Type II SPDC process we use, the photon pairs are inherently polarization-entangled. In addition to room-temperature operation, the material platform we are using enables the direct integration of a pump laser onto the same chip, a technical implementation of which we are currently investigating.

Quantum Cascade Lasers in Application

In addition to laser modules, we also develop demonstrators that use quantum cascade laser modules from Fraunhofer IAF. By enabling contactless measurement of the chemical fingerprint of substances, these modules facilitate, for example, quality assurance in tablet blister packaging in the pharmaceutical industry or forensic analysis at crime scenes.

Fraunhofer IAF’s expertise in the field of semiconductor lasers is available to scientific institutions and companies both for conducting research and development projects and for direct commissions. Successful collaborations regularly yield outstanding results.

Semiconductor disc laser module (VECSEL) in the 2 µm range

• 2062 nm emission wavelength
• 2.5 W CW output power
• Single-frequency
• Low intensity noise (0.15% RMS)
• Free-running: Drift less than 7 pm over 15 h
• Actively stabilized to a frequency comb:
  • Linewidth 360 kHz (FWHM)
  • Standard deviation of the emission wavelength over 22 h:
  • 104 kHz (1.5 fm)

4-core quantum cascade laser module in the 4–11 µm range

• Multi-core module with integrated beam combining
• Equipable with up to 4 spectrally tunable MEMS-EC-QCLs with central wavelengths between 4 and 11 µm.
• Tuning range of a single module: 200–330 cm^-1, depending on the QCL chip used
• Pulse operation, typically 100–200 ns
• Spectroscopy over 1000 cm^-1 with a measurement rate of 1 kHz

Entangled photon pair source

• Telecom C-band (1530–1565 nm)
• Chip size of a few square millimeters
• Photon generation rate 20 MHz at 5 mW external pump power
• Fidelity to Bell state > 95 %