This year, Juozas Vidmantis Vaitkus,
Professor Emeritus at Vilnius University, a member
of the Lithuanian Academy of Sciences and well-known expert in
semiconductor physics and optoelectronics, celebrates his 80th
anniversary. In 2020, we celebrated, though without having him
among us anymore, the 75th birth anniversary of
another outstanding Lithuanian
physicist, Professor Remigijus
Baltramiejūnas, who also substantially
contributed to paving the way for semiconductors towards
photonics applications. This issue of the
Lithuanian Journal
of Physics is dedicated to recognize the
achievements of these two Lithuanian experts in semiconductor
photonics. The authors of papers in this collection consider
Prof. J.V. Vaitkus and Prof. R. Baltramiejūnas their
teachers or colleagues. Most of the topics of papers presented
here are related to the research activities of these two
scientists, but do not by far cover the entire research field
enriched by their significant contributions.
In the late 1950s, silicon took the lead over
germanium as the semiconductor of choice to start its
exponential breeding fuelled by Moore’s law to enable the
fabrication of your cellphones containing several billions of
transistors. Those days, in the Lithuanian town Šiauliai
two guys, Juozas and Remigijus, took one after another the lead
in the radio shack, where the shortwave radio equipment, still
based on vacuum tubes and predominantly home-built, enabled
reaching places thousands of kilometers away from their homes.
Their first long-distance transition in real space was to
Vilnius. Both guys graduated from Vilnius University, the oldest
university east from Krakow, became members of its Faculty of
Physics and made a significant contribution to the development
of their
alma mater into a modern research
university. In the sixties, semiconductor physics was a
challenging and bursting research field, and semiconductor
electronics turned the vacuum
tube-based electronics into an
obsolete technology. Meanwhile, Juozas
and Remigijus got interested in the interaction of
semiconductors with light. This love lasted forever. Invention
of a laser in the sixties
offered new capabilities in
studying photoelectric properties of
semiconductors. Juozas and Remigijus were among the first
semiconductor researchers to exploit the opportunity. Building
their first laser from scratch was their first step to laser
spectroscopy and exploitation of nonlinear optical
phenomena for characterization of
semiconductors and, later on, semiconductor
nanostructures. These activities involved an avalanche-like
increasing number of young physicists and grew up into a
solid contribution to the
development of photonics, which is currently
one of the leading R&D fields in Lithuania.
Photo below: R. Baltramiejūnas and
J.V. Vaitkus in 1970s
Serving as the
Chair of the Semiconductor Physics Department for
two decades and as the
Director of the Institute of
Applied Research at Vilnius
University, Prof. J.V. Vaitkus
exploited his bright scientific
vision in good times and was
able to perform his administrative duties in hard times.
Exceptionally broad and deep
erudition is his hallmark admired
by his colleagues physicists as
well as nonscience students and
other audiences, who had a chance to attend his lectures
or have discussion with the Professor. The broad scope of his
scientific vision led his research activities on defects in
semiconductors to applications important in
high-energy physics experiments at
CERN well before Lithuania became
an associated member of this
prestigious international research
organization. His name stands in research
papers among a few hundreds of physicists, who contributed to
the discovery of the Higgs boson.
Asked to list three most distinguished
features of Prof. R. Baltramiejūnas, his
former colleagues and students
would definitely point out his
energy, ability to spot the key
issues in any problem, and intrinsically positive attitude
towards people, though sometimes invisible due to directness in
expression of his opinions. He was bright and attracted bright
people. Many physicists, who started their scientific careers in
Prof. Baltramiejūnas’ research team at Vilnius University,
became experts in semiconductor photonics and are active in
research. Prof. R. Baltramiejūnas also served as the Director of
the Institute of Physics and substantially boosted the
development of this research institution.
By publishing this commemorative issue of the
Lithuanian Journal of Physics, we are joining the celebration of
anniversaries of Prof. J.V. Vaitkus and Prof. R. Baltramiejūnas
to honour their scientific achievements and impact on
semiconductor photonics.