When nonlinear optical materials are exposed to intense laser radiation, processes are triggered inside of them that create light with different wavelengths. These processes include frequency doubling, sum-frequency generation, and optimal parametric generation.
- Frequency doubling is well-known since this process forms the basis of green laser pointers.
- Optical parametric generation converts a fixed pump frequency into tunable laser light by using quasi-phase-matched materials. Optical parametric oscillators based on periodically poled lithium niobate or lithium tantalite emit light from the visible to the terahertz frequency range.
- Sum frequency generation is employed to transfer light with wavelengths from the mid-infrared range into the wavelength range below 1 µm in order to detect it by using standard silicon detectors and pixel sensors.
Fraunhofer IPM specializes in frequency converters based on continuous-wave lasers. These systems enable the generation of single-frequency laser light for spectroscopic and holographic applications. However, they also impose high demands on optical design. Fraunhofer IPM can draw on many years of experience in structuring and functionalizing lithium niobate. In addition, fundamental research carried out at the associated Laboratory of Optical Systems at the University of Freiburg gives us access to the latest research findings in this field.