Coherent Optics

The Department of Coherence Optics (former Quantum Generators of Light) was founded on the basis of the former Section of Infrared Spectroscopy at ISI shortly after the invention of lasers. F. Petrů was its head until 1999. At the beginning of 1960s the department was focused on the field of infrared spectrophotometry. From March 1963 the department had started work on manufacturing the first lasers in both solid and gaseous states. The department's staff was successful in both directions. Results came extremely quickly, as no longer than six months after this work began in October 1963 a stimulated emission at a wavelength of 1.15 μm was recorded, and shortly afterwards emissions at 3.39 µm and 633 nm obtained. An He-Ne laser working at a wavelength of 633 nm had already existed for two years and the technology of its production had not been published at that time. After being quickly put into production three types of lasers of different powers were displayed at the Brno Trade Fair in 1964 by their producer Meopta Přerov. A pulse laser was put into operation in 1964 and a machine for drilling diamonds was developed on its basis. Since 1967 the exact measurement of geometrical quantities by means of interference methods has been the main focus of the department. A frequency stabilized single-mode He-Ne laser was developed and formed the basis for the Czechoslovak laser sub-normal of lengths which was used by the metrological institutions of this country in the 1970s. Another achievement was the compact transferable and modular interferometric system (LIMS) that was designed for mechanical engineering and had several new functional possibilities –length measurement up to three axes, measurement of speeds, flatness, small angles with the possibility of correction to the air refractive index. In 1981 – 1982 a precise laser interferometric system was constructed. It measured the position in two coordinates with an accuracy of 40 nm as well as speed. From 1984 the department focused on the development of He-Ne lasers stabilized by the use of saturated absorption in iodine vapours, increasing the accuracy of interferometric systems, two-colour and absolute interferometry.
In 1995 J. Lazar, P. Zemánek and O. Číp focused on the use of semiconductor diodes in metrology, and in particular on increasing their coherence, frequency stabilization, and interferometric systems with a tuneable laser source. These results were recently used by F. Petrů for a new type of laser refractometre. In 1995 P. Zemánek established a new direction for the department exploiting focused laser beams for manipulation with nano- and micro-objects or microablation. Gradually new types of optical traps were developed, together with methods of measurement of pN forces, micro-particle sorting and laser induced fusion of living cells