Laser Components Department
The roots of the Laser Component Department can be traced back to the beginning of the 70s. The earlier working group “Dielectrical Coatings” of the Institute for Applied Physics, which had been renamed to the present Institute of Quantum Optics of Leibniz Universität Hannover, concentrated on the production of optical coating systems and the characterization of losses. The group moved into the new building of the Laser Zentrum Hannover e.V. in the year 1992 and formed the basis for the Department of Laser Components. In the course of more than four decades of research activities in the field of high quality coated components, important contributions to ion assisted deposition processes (IAD) and ion beam sputtering (IBS) processes, as well as highly precise control of coating processes and characterization of laser components could be made. The extensive lab and clean room infrastructure of the LZH can be used for a number of process concepts. Apart from this, there are standardized characterization facilities for transfer properties from the VUV to the FIR spectral range, optical losses, laser-induced damage thresholds and the stability of optical components.
Current research activities of the Laser Components Department include complex coating systems for high-power laser systems, optical metrology and inspection metrology. The group is mainly concerned with innovative process concepts and highly precise control procedures for coating processes, which are in use in industry in developmental areas for economical production strategies. Furthermore, based on this foundation, new processes for the controlled production of ternary coating phases and for structures with a continuous variation of the refractive index could be tested. Developmental work in the field of modern metrology methods can be used for a further field of work of the department, i.e. the construction of customer-specific VUV spectral photometers, wide-band spectrometers for process control, and set-ups according to ISO standards. Such equipment from the department has been in use for a number of years in industrial enterprises and research groups in many countries. This has served as a motivation for department activities in the area of developing standards for examining and testing optical components. Finally, based on the coating processes developed and the characterization work done, special coatings according to customer specifications can also be offered in small quantities.
Fundamental Research and Networks
Current approaches in the field of fundamental research concentrate on the understanding of coating structures with defined mixing phases, nonlinear properties, quantum wells and highest laser induced damage thresholds. Some special initiatives are for example:
Further activities are presently concentrated on the development of novel laseractive polymer fibers within the project “Design, Herstellung und Charakterisierung von laseraktiven Polymerfasern” (DEHERA) within the cooperation “Laseraktive Polymeroptische Fasern” (LaPOF) funded on the basis of the “Europäischer Fonds für regionale Entwicklung” (EFRE).
The department is also involved in the Masterplan “Quanten- und Nanotechnologie” of the Universities in Hannover and Braunschweig featuring the research group “Integrated Photonics”. This new junior research group is dedicated to the development of laser active fibers for applications in space and will build up a complete infrastructure for the production of doped optical fibers in the HiTec-Building in cooperation with the Laser Zentrum Hannover. The facility includes an MCVD preform production system, a modern fiber drawing tower and a variety of adapted characterization systems.
Within the framework of the cluster of excellence QUEST (Quantum Engineering and Space Time Research) a working group “Advanced Materials” could be established which concentrates on basic research in the field of ion beam sputtering processes.
The lab and cleanroom infrastructure at the LZH allows for the demonstration and implementation of various process concepts for optical coatings. Moreover, standard-compliant characterization methods for transmission properties from the VUV to the FIR spectral range, optical losses, laser-induced damage thresholds and the stability of optical components are available.
Within COMET, the Laser Components Department at the LZH and the Thin Film Department of the Fraunhofer Institut für angewandte Optik und Feinmechanik (IOF) have created an optimum cooperation to be able to fulfil even complicated and most difficult demands on the optical components of tomorrow.
The goal of the Research Center for Surface Technology (RCST) is to foster field of thin film and surface technology in the European research landscape and to provide a continuous basis for research and development activities. It has been founded by the Russian and German Ministries on the basis of the research groups of Prof. Alexander Tikhonravov at Lomonosov University and the Laser Components Department of Prof. Detlev Ristau at the Laser Zentrum Hannover e.V. in Mai 2011.