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Open access article / Atviros prieigos straipsnis
Lith. J. Phys. 62, i–ii (2021)
 

DEDICATION TO TWO PIONEERS OF SEMICONDUCTOR PHOTONICS IN LITHUANIA

Baltramiejunas-Trise
Remigijus Baltramiejūnas (left) and Juozas Vidmantis Vaitkus
(centre)  with  the  Editor-in-Chief  (2002–2008)  of  the
Lithuanian Journal of Physics Zenonas Rokus Rudzikas

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
RB-JV    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.

Gintautas Tamulaitis