The originator and pioneer of fluorescence line narrowing and spectral hole-burning of the solid state, Alexander Szabo, 86, died on 11 June 2017 at the Ottawa General Hospital, Canada, after a short but courageous battle with pancreatic cancer.
Born in Copper Cliff, Ontario, Canada, on 13 March 1931, Alexander grew up with his parents and younger brother, Frank, in Sudbury. As a child, he loved to take things apart and put them back together again and loved watching Buck Rogers and later, Star Trek.
He showed intelligence at an early age, skipping a grade to enter high school at a younger age than his classmates. He was very active in sports and played hockey and golf. In high school, he played on the football and basketball teams. He was also a top billiard player, a great chess player, and was talented at drawing.
Alexander graduated with a BSc from Queen’s University in Kingston, Ontario in 1953, obtained a MSc degree from McGill University in Montreal in 1955, as well as a PhD in laser and optical engineering from Tohoku University in Japan in 1971. He won numerous scholarships and awards including the B’nai B’rith Prize in Mathematics at Sudbury High School (1949), the Gold Medal in Physics and the Brookland Radio Prize while at Queen’s (1953), and the Ontario Research Award while at McGill (1954).
Alexander started working at the National Research Council Canada (NRC) in May 1955 in the vacuum tube laboratory of the electrical engineering department, working on the theory and experiments of electron beams. Between 1959 and 1963 he researched electron paramagnetic resonance and relaxation in low temperature solids, and that lead to his work on the ruby laser, as a potential pump source for a ruby maser. Within the framework of those studies, Alexander and Boris Stoicheff, with two Nobel Prize winners in attendance, Gerhard Herzberg of NRC and Arthur Schawlow from Bell Labs, who was visiting at the time, demonstrated the first laser in Canada in the spectroscopy lab at the NRC on 12 January 1961.
Between 1964 and 1969, Alexander studied laser Q switching by a saturable absorber, laying the foundations of his PhD work on optical pumping of ruby by laser resonance radiation. That again was the stepping stone to his seminal papers on laser-induced fluorescence line narrowing (FLN) in ruby. Shortly after that paper, Alexander reported on the first observation of spectral hole-burning in the solid state, again a groundbreaking paper. In 1972 Alex also lodged his original patent on optical data storage by hole-burning; the patent was granted in 1975. This significant idea opened up real-world applications that are researched to date. In particular, Alex’s papers on FLN and hole-burning basically generated the research field of high-resolution laser spectroscopy of the solid state that has been intensely researched to this day, both at university and industrial laboratories. The two techniques allow unprecedented insights into the finest details of the electronic structure of materials by circumventing the ubiquitous phenomenon of inhomogeneous broadening.
From the 1970s to 2017, Alexander continued to work on the spectroscopy of ruby and made further groundbreaking and original contributions to the field of laser spectroscopy of the solid state by continuing his work on hole-burning and coherent transients such as optical free induction decay, optical nutation, photon echoes, etc. Nominally, Alex retired on 31 May 1996, after 41 years of service to the NRC, but then continued to work right to the end as a researcher emeritus at the Institute for Microstructural Sciences.
Since the discovery of the red luminescence lines (R-lines) by Becquerel, ruby always played a paramount part in the development of solid-state spectroscopy of insulators. For example, the ligand field theory was developed around ruby by Tanabe and Sugano in the 1950s, and this was the foundation of the first demonstration of laser light by Maiman in 1960 at the Hughes Aircraft laboratories in Malibu. It is fair to say that Alexander devoted his scientific life to ruby and had the most incredible and profound knowledge of the spectroscopy and quantum mechanics of this system. It was a great pleasure and honor to work with Alex; shortly before his death we (HR and AR) managed to publish yet another significant paper on ruby, demonstrating ultra-slow solitary light propagation in high magnetic fields and low temperatures. Alexander leaves behind a legacy of incredibly meticulous and pioneering work.
Alexander always said that the thing that motivated him the most was “curiosity”—and this is the word that defines him the most.
He was married for nearly 60 years to Ethel Jessie and was the father to Susan, John, Eleanor, and Jennifer. He loved listening to 1950s and big band music, playing hearts, and watching CNN.
On his headstone is a prism to commemorate his interest in science. Among the items buried with him include a Queen’s Alumni Review magazine, a crossword puzzle, a picture of his family, and . . . a Physics Today magazine.
