The science of quantum electronics dates back to 1954, when the first microwave quantum oscillator, the maser, was developed. However, the development of the science was given a much greater impetus by the development of the optical quantum oscillator, the laser, in 1960. Interest in lasers and non-linear optics as promising new fields of science began at Vilnius University immediately after the development of the laser. The beginning of the history of laser physics was in 1962, when the then head of the Department of Radiophysics, Prof. P. Brazdžiūnas, sent three students - A.P. Piskarskas, E. Maldutis and I. Gulbinaite to continue their studies at Moscow Lomonosov University, which they successfully completed in 1965. Stabinis and K. Burneika. The promise of quantum electronics began to emerge during their studies in Moscow, when the Nobel Prize was awarded in 1964 to N.G. Basov, A.M. Prokhorov and Ch.H. Townes for their achievements in laser physics. The first two worked at the Moscow physics institutes and worked closely with Moscow University, so that the level of quantum electronics studies there was very high. Physicists from all over the world, mainly Americans, French and Germans, used to visit. After graduation, all the students who were sent to study there entered the postgraduate course at Moscow University, defended their dissertations and returned to Vilnius University to continue their research work (except for I. Gulbinaitė, who entered the postgraduate course at MVU two years later, and then went to the USA).
Nobel laureate (1964) Ch. Townes visits Moscow's Lomonosov University (1965). Seated from right to left: Professors S. Akhmanov, Ch. Ch. Achmanov, Ch. Townes, R. Khokhlov, S. Korniyenko. Standing in the first row from right to left: postgraduates A. Piskarskas, M. Dzhizhiev, B. Akanaev, V. Fadeev
The contacts with foreign researchers made during his postgraduate studies were of great help to scientists later on, especially to the future head of the Department of Quantum Electronics, academician Professor A.P. Piskarskas, in establishing contacts with the world's strongest laser physics centres, in organising the Vilnius International Laser Physics Conferences, and in publicising the achievements of Lithuanian laser researchers to the world. Interestingly, in 1964-1965, while still a student, A.P. Piskarskas and his co-authors published the results of their first research in a prestigious scientific journal. This was the first article by a Lithuanian physicist on the interaction between laser radiation and matter. A.P. Piskarskas then studied the wavelength changes of laser radiation as it propagates through crystals and observed for the first time the phenomena of parametric amplification and generation of light. Similar phenomena were also described by physicists in the USA at the time, and A.P. Piskarskas' work is often cited alongside that of overseas colleagues.
A. P. Piskarskas, a postgraduate student at Moscow Lomonosov University, experiments in a laser laboratory with graduate student V. Kolosov (1967)
When they returned to work at Vilnius University, a group of like-minded people began to form, united by a common interest in quantum electronics. They were joined by R. Rakauskas, a senior lecturer at the Department of Radiophysics. Thus, in 1969-1970, a strong group of theoreticians and experimentalists was formed, determined to work in the new field of physical science. Under the leadership of senior lecturer R. Rakauskas. A.P. Piskarskas, the development and research of continuously tunable frequency lasers was carried out. Senior Lecturer A. Piskarsky and Prof. A. Piskarsky have been working on a series of research projects. R. Rakauskas studied energy migration processes in rare earth mantles. Senior Lecturer. E. Maldutis investigated the mechanisms of disruption of non-linear crystals by strong laser radiation.
In 1970, the Department of Electronics was established and quantum electronics specialists were transferred from the Department of Radiophysics. The Department of Electronics trained physicists specialising in electronics, and quantum electronics became the Department's main scientific focus. It was devoted to parametric light generation in non-linear crystals by changing the conditions of amplification and modulation, to the first study of simultaneous phase and group synchronism, to increasing the efficiency of parametric wave interaction, and to the study of non-linear wave interaction in crystals under the influence of high-intensity picosecond pulses of laser radiation (A.P. Piskarskas, A.P. Stabinis and K. Burneika).
The patriarch of Lithuanian experimental physics, academician P. Brazdžiūnas (middle), the pioneer of laser physics and non-linear optics research at Vilnius University, the head of the Department of Astronomy and Quantum Electronics, doc. A.P. Piskarskas and Dr. R. Danielius (1982)
1971 Senior Lecturer. Maldutis moved to the Institute of Semiconductor Physics, where he founded the Laboratory of Laser Radiation and Material Interaction. In 1972, quantum radiophysics was included in the plans for the Molecular Acoustics Problem Laboratory. New research topics were formulated, three of which were in the field of quantum electronics: the development of continuously tunable parametric ultrashort pulse generators in the 0,78¸1,65 mm range; the design and study of stable phototropic films for controlling ultrashort pulses in solid-state lasers; and the development and fabrication of an automated device for the measurement of ultra-small variations in the refractive index of nonlinear crystals (5-10-3).
In 1974, the Department of Astronomy and Plasma Physics was reorganised into the Department of Astronomy and Quantum Electronics as part of a further reorganisation of the departments in the Faculty of Physics. It remained under this name for 14 years, until 1988, when it was renamed the Department of Quantum Electronics. In 1972, Assoc. A. Misiūnas, who continued to head the Department after the name change. At the end of his term of office in 1978, A.P. Piskarskas. As the work expanded, the Laser Research Centre (LRC) was established in 1983 and A.P. Piskarskas was appointed its head. In the same year A.P. Piskarskas defended his PhD (now Habilitated Doctorate) thesis in Physics and Mathematics on "Wide Range Picosecond Parametric Light Generators and their Application in Spectroscopy of Ultrasonic Processes". 1984 A.P. Piskarskas was awarded the title of Professor. In the same year, together with his laser colleagues from Russia, Belarus, Ukraine and Uzbekistan, he was awarded the USSR State Prize for Science and Technology for his research on non-linear optics. Prof. A.P. Piskarskas held the position of the Head of KEK until 2012. Piskarskas is Professor Emeritus of Vilnius University. Prof. V. Sirutkaitis was elected Head of the Department of Quantum Electronics in 2012.
In 1978, after the construction of the new building of the Faculty of Physics in Saulėtekis Avenue, the Department moved to new premises. Until 1981, the posts of the Department were mainly economic, and therefore the researchers in these positions were on economic contracts. At the same time, in-depth fundamental and applied research was carried out in the fields of ultrashort pulse generation, parametric light generation and ultrafast spectroscopy. This work was widely known, and the Department was therefore eligible for budgetary funding for topics coordinated by the USSR State Scientific and Technical Committee. As a result, in 1981-1983 the Department received a large number of new posts of researchers and engineers and the number of staff increased to 70. Scientific laboratories were set up and equipped with the latest equipment with the help of economic contracts. This created favourable conditions for the development of research. Part of these funds were also used to maintain and improve the Department's teaching laboratory. When the budgetary and economic research groups were merged into the Laser Research Centre in 1983, part of the premises in the dormitory complex on Saulėtekio Avenue (Saulėtekio Avenue 10) were reconstructed into the Laser Research Laboratories. The reconstruction of the canteen into laboratories lasted for more than a year and involved the active participation of all the scientific and technical staff of the Department, who contributed in various ways to the construction and installation work.
Until 1991, economic contracts were mainly carried out for various scientific and industrial institutions of the USSR. In the period 1969-1990, 83 economic contracts were concluded for fundamental and applied research in the fields of non-linear optics, laser physics, laser material processing and laser medicine. In parallel, the development of various prototypes of laser devices started as early as 1983. These include: a picosecond spectrometer consisting of a picosecond laser and one or two parametric light generators; various optomechanical assemblies for laser circuits; stable ultra-short pulse lasers with feedback; optical harmonic generators; and special nanosecond pulse lasers. At that time, the number of teaching and research staff working in the field of quantum electronics had risen to 85. Following the completion of the economic contract for the S. Vavilov Institute of Optics in Leningrad in 1991, there were no more contracts with companies of the former USSR.