Interferometric distance measurement system
Technologies from microsystems engineering and microoptics form the basis for the successful miniaturization of a new, interferometric distance measurement system from TETRA GmbH in Ilmenau.
The mechatronics specialist developed the core component, consisting of a Michelsen laser interferometer and an optical silicon detector, together with the Microoptical Systems Application Center at the CiS Research Institute in the BMBF-funded VAMIS R&D project. The result is a highly compact – the installation volume is only 0.5 cm³ – and extremely stable OEM module for integrators and customers in automation technology.
The assembly can be used for distance measurements in the range of 0.5 – 5 mm and achieves a resolution of less than 1 nm. Important subcomponents were developed and optimized in the application center based on platform technologies.
These include a microprism that acts as a beam splitter and contains a polarization-independent, dielectric 50:50 splitter layer. Furthermore, an illumination unit consisting of a 670 nm VCSEL diode and a specially adapted POG micro-optics for beam shaping and concentration of the light spot on an area of 0.5 mm²), an adjustable aluminum- or titanium-coated reference mirror and a detector element, as SMD-capable photodiode array on glass substrate for flip-chip mounting on LTCC or PCB substrates.
For an efficient, cost-effective and industry-ready production of the microcomponents, batch-capable processes, semi-automated assembly technologies (packaging and interconnection) and certified test and inspection methods are used at the mikrooptische systeme application center.
Visit us at the SENSOR+TEST 2012 trade show in Hall 12, Booth 226 and learn more about our broad range of services in sensor and optics, microstructure and assembly technologies.