Professor Oswald Leroy, Doctor Honoris Causa of the Gdańsk University
The Doctor Honoris Causa title was conferred upon Professor Oswald Leroy by the Senate of the University of Gdańsk on the 8th of February 1991 to distinguish his contribution in the field of physics , particularly in acousto-optics . At that time, the 20 years co-operation in this domain between Professor Oswald Leroy and the group of physicists of the Gdańsk University has brought significant profit and credit to our University.
Prof. O. Leroy`s DrHC Certificate
Prof. O. Leroy`s Doctor Honoris Causa ceremony University of Gdansk,8th February 1991
Prof. O. Leroy`s Doctor Honoris Causa ceremony University of Gdansk,8th February 1991
Professor Oswald Leroy was born at Passendale, Belgium, in 1936. He completed his study in mathematics and physics in Gent University and got the Ph.D degree in nineteen fifties of the XX century for the Thesis on “Diffraction of light by ultrasound” in the group of Professor Robert Mertens who developed the well-known Belgium team working on the theory of the ultrasonic light diffraction phenomena in 1950-ties and 1960-ties. Professor Leroy initiated and had continued research on light and ultrasonics interaction in the Kortrijk-Campus of the University of Leuven since it was erected in 1965. He created his own group there and widely developed the theory of light diffraction by two ultrasonic beams studying the phenomenon against the whole frequency and intensity range depending on the phase shift between the beams. His original papers predicted new phenomena which were not then yet experimentally verified. They became inspirational for further search in acousto-optics especially when active development took place after the discovery of lasers. The theoretical predictions of Oswald Leroy’s papers were experimentally verified in the Acousto-optical Laboratory of the Institute of Experimental Physics of the University of Gdańsk as a result of a fruitful common scientific co-operation started in 1971 and being continued until now.
Numerous, common, mutually inspiring papers were published (see the References below [1-27]) during the long research co-operation. A particular history of the co-operation presents the contribution of Professor Leroy and his coworkers to the participation in the international Spring Schools on Acousto-optics and its Applications organized by the Institute of Experimental Physics UG as the three annual event since 1980 [26,27].
At the time of conferring the Doctorate HC of UG on Professor O. Leroy in 1991 he was the author of many papers not only in acousto-optics. One can mention his papers related to such problems as: the symmetry in physics, proofs of existence of solutions of heavy particles in the field of the Earth, construction of self-coupling Hill operators having periodic eigen functions, new approach to propagation of electromagnetic and elastic waves in non-homogeneous media, behaviour of waves on a statistically non-uniform liquid-solid boundary, mechanism of reflection of bend waves, non-linear effects of the propagation of non-homogeneous waves; and many others. His achievements have increased during following years (see the list of Oswald Leroy’s about 230 publications on www.kuleuven.be/wieiswie/en/person/00004199). Oswald Leroy’s papers were and are cited in many articles and they were published in books.
The set of occasional photos of the doctorate Honoris Causa ceremony to Professor Oswald Leroy at the University of Gdansk is situated in the album.
In 1993 on the 21st September Professor O. Leroy as the invited guest of the UNiversity of Gdansk took part in the solem ceremony of the Doctor Honoris Causa titles conferment upon the European Presidents: Francois Mitterrand, France, Richard von Weizsakers, Germany and Lech Walesa, Poland.
|The Presidents (from the left): Francois Mitterand, Lech Walensa, Richard von Weizsakers during the Doctor Honoris Cause ceremony, University of Gdansk, Gdansk, 21st September 1993||Prof. O. Leroy (the head in the left upper corner) as the guest invited by the University of Gdansk during the DHC ceremony for the Presidents: Francois Mitterand, Lech Walesa, Richard von Weizsackers, Gdansk, 21st September 1993.||Prof. P.Leroy (handing the blue card) as the guest invited by the University of dansk during the Doctor Honoris Causa awards to the Presidents: F. Mitterrand, L. Walesa, Richard von Weizsackers, Gdansk, 21st september 1993.|
For a few years now, Professor Leroy is retired keeping contacts with his many alumni and co-workers and widely recognized as an authority in the world physicists community being concerned with ultrasonics. Evident example of that was the organization of the Special Session in Honour of Professor Emeritus Oswald Leroy entitled Acousto-Optic Interactions and Wave Phenomena in Optics and Acoustics at the consecutive International Congress on Ultrasonics (ICU’2015) in Metz, France, May 11-14, 2015. At the Session, there was time to recognize Professor Leroy’s credit to the University of Gdansk where some recollections of mutual co-operation and of the event of the UG Doctorate Honoris Causa ceremony were presented  (occasional presentation). Also, during the Session Professor Leroy was awarded the Medal of the University of Gdansk.
References (re. Oswald Leroy’s cooperation with Gdansk University)
- O. Leroy, Diffraction of light by adjacent ultrasonics, in Acoustics and Spectroscopy, A. Kawski and A. Śliwiński, Eds. (Societas Scientiarum Gedanensis, Gdańsk; Ossolineum Wroclaw, 1979), pp. 45–56.
- P. Kwiek, O. Leroy, and A. Śliwiński, On the verification of the theory of ultrasonic light diffraction by adjacent ultrasonics, Acoust. Lett. 1, 130–133 (1978).
- O. Leroy , P. Kwiek, A. Śliwiński, Light diffraction by ultrasonic beams having phase difference δ, in Proc of the First Intern. Symp.. On Ultrasonic Materials Characterization, NBS (National Bureau of Standards), Gaithersburg, Md., USA, 1978, NBS Special Publication 596,1980, pp. 657–663.
- P. Kwiek, O. Leroy, A. Śliwiński, Verification of the theory of an ultrasonic light diffraction by adjacent ultrasonic beams, FASE II, Warszawa 1978, II-37, 193 -196.
- P. Kwiek, A. Śliwiński, O. Leroy Measurement of the ultrasonic pressure of the second harmonic using ultrasonic-light diffractionby adjacent beams, Proc. of Ultrasonic International 79,Graz, 1979, 494-499
- O. Leroy , A. Śliwiński, P. Kwiek, and A. Markiewicz, Diffraction of light by adjacent fundamental and second or fourth harmonic ultrasound beams: comparison of exact and simplified formulae with experiments, Ultrasonics 20, 135–141 (1982)
- O. Leroy, P. Kwiek, A. Śliwiński, Light diffraction by two adjacent ultrasonic beams of frequency ratio 1:1, Acoustics Letters, 5, 1982, 159-164.
- E. Blomme , P. Kwiek, O. Leroy, A. Markiewicz and A. Śliwiński, Amplitude-time modulation of light diffracted by two ultrasonic beams propagating in opposite directions, Proc. Of Ultrasonics, International, London Butterworth,1985, pp. 533–538.
- E. Blomme , P. Kwiek, O. Leroy, A. Śliwiński, Higher Order Bragg Diffraction of Light by Ultrasound: Theory and Experiment, Proc. of Ultrasonics International, 93, Butterworth- Heinemann, Oxford,,1993, pp. 69–72.
- E. Blomme ,O. Leroy, A. Śliwiński, Ultrasonic control of light polarization in fused silica, Proc. IEEE,Ultrasonics Symp.,Cannes, France, 1994, vol. 2, 893-896.
- E. Blomme , O. Leroy, A. Śliwiński, Acoustically induced light polarization effects in isotropic media, Acousto-optics and Applications II, A. Śliwiński, P.Kwiek, B. Linde, A. Markiewicz, Eds, Proc. SPIE 2643, Bellingham, USA, 1995, 2-11.
- E. Blomme , O. Leroy, A. Śliwiński, Numerical and experimental comparison of polarization effects in ultrasonic light diffraction in intermediate range in isotropic SiO2, Acousto-optics and Applications II, A. Śliwiński, P.Kwiek, B. Linde, A. Markiewicz, Eds, Proc. SPIE 2643,Bellingham, USA, 1995, 115-121.
- E. Blomme, O. Leroy, A. Śliwiński, Light diffraction and polarization effects in isotropic media with acoustically induced anisotropy, Acustica – Acta Ac., 82, 1996, 464-477.
- E. Blomme, O. Leroy, A. Śliwiński, Acoustically Induced Light Polarization Effects Under Bragg and Near-Bragg Conditions, 10th Topical Meeting of the European Optical Soc., CNET, Paris, 6-7 June 1996, 20-21.
- E. Blomme, P. Kwiek, O. Leroy, A. Śliwiński, Polarization Effects Induced by Ultrasonic Light Diffraction in Isotropic Media: Dependence on the Incidence Angle, 10th Topical Meeting of the European Optical Society, CNET, Paris, 6-7 June 1996, 24-25.
- E. Blomme, O. Leroy, A. Śliwiński, Light polarization effects in isotropic media with acoustically induced birefringence, Proc. of WCU 97, Yokohama,1997, 476-477.
- E. Blomme, G. Gondek, T. Katkowski, P. Kwiek, O. Leroy, A. Śliwiński, Experimental and numerical comparison of the symmetry in polarization states in the ultrasonic light diffraction induced birefringence, E.O.S. Meet. Dig. Series, Vol. 21, Adv. in Ac.- optics, AA-O’98, ISSN 1167-5357, cOrsay Cedex – France, 1998, 50-51.
- E. Blomme, G. Gondek, T. Katkowski, P. Kwiek, A. Śliwiński, O. Leroy, On the near field of light diffracted by ultrasound in an isotropic medium with acoustically induced anisotropy, Acousto-optics and Applications III, A. Śliwiński, B. Linde, P.Kwiek,Eds, Proc.SPIE 3581, Bellingham, USA,1998, 153-162.
- E. Blomme, G. Gondek, P. Kwiek, O. Leroy, A. Śliwiński, Time dependence of polarization effects in the optical near field of light diffracted by ultrasound in an isotropic medium, Advances in Acousto-Optics, Belgium, Bruges, 25-26 May ,2000, 15-16
- E. Blomme, A. Śliwiński, Ultrasonic light diffraction in optically isotropic media with induced birefringence, Acousto-optics and Applications IV, B.B.J. Linde, A. Sikorska, Eds, Proc. SPIE, Vol. 4515,Bellingham, USA, 2001,33-40.
- A. Śliwiński, Modulation effects in light diffraction by two ultrasonic beams and application in signal processing, in Physical Acoustics, Fundamentals and Application, O. Leroy, M. Breazeale, eds,Plenum,1991, pp. 165–178.
- A. Śliwiński, Acousto-optics in Poland, Opt. Eng., 1992, 31, 2062–2072.
- R. Mertens, Fifty years of acousto-optics, Proc. of the 11th Intern. Congr. on Acoustics (ICA), Paris, Societe Francais d’Acoustique1983, Vol. 8, pp. 101–113.
- O. Leroy and R. Mertens, Theoretical acousto-optics in Belgium, 1992, Opt. Eng. 31, 2048–2061.
- R. A. Mertens, Sixty years of acousto-optics. Fifty years of scientific research at two Flemish universities (Gent and Leuven-Kortrijk), Acad .v. Wetenschappen, Letteren en Schone Kunsten v. België, Acad. Anal.,Kl. d. Wetenschappen, 1995, 57, 3, pp. 1-82.
- P. Kwiek, A.Śliwiński, Some recollections on acousto-optics research at the University of Gdańsk in the light of international cooperation and of the history of Spring Schools on Acousto- Optics and Applications, Appl. Optics, 48, 7,(2009), C125- C134.
- A.Śliwiński, Research cooperation between Catholic Universityof Leuven Campus Kortrijk and University of Gdansk in acousto-optics - a historical recollection* (a tribute to Oswald Leroy for his significant contribution to acousto-optics; presented at the occasional session of ICU’2015 Metz, France), Physics Procedia, 70 (2015) 779-782; on website