AILU was very sad to hear of the passing of Jyotirmoy "Jyoti" Mazumder (09/07/1951 - 10/04/2021). Professor Bill Steen (AILU's first President) was Jyoti's PhD supervisor at Imperial College London in the late 1970s, and writes a personal and fitting tribute below.
"It is not usual, and it is sad, for a supervisor to write an obituary to one of his top students; but that is what I am doing. Jyoti Mazumder scaled the heights of academic achievement being recognised as a leading thinker in the field of laser material processing by his election to the USA National Academy of Engineering, the Indian National Academy of Engineering, and the winning numerous awards.
He joined my embryonic research group at Imperial College, London in 1977 to work on the newly acquired Control Laser 2 kW CO2 FAF laser. It was at that time a rare industrial laser with significant power and the best mode structures available at the time, so we found out.
Ours was one of the first University-based research groups working in this field. Jyoti was in his element as a scientific pioneer. He sailed through his PhD on laser welding of mild steel and titanium, laying a significant foundation in that topic. This in spite of having come straight from Calcutta into the wet and cold of London at a time when the Government of India would not allow his father, a wealthy businessman, to help him financially. His first paper was given at the Munich ‘78 conference “Laser welding of Titanium 6Al-4V” a year later.
Being at Imperial College in 1978 we had access to one of the few large computers in the world and so together we built a finite difference model of a laser-heated spot and a moving laser spot, (all on punched cards) which much to our surprise led to one of our more frequently cited papers [Mazumder J , Steen W.M. “Heat transfer model for CW laser processing” J. App. Phys Feb 1980 51 (2) pp.941-946].
He was always searching for the next development and he had the talent to exploit it when he found it. He alerted me to the idea that surface treatment might be the next idea to explore. I considered that using the quality laser beam out of focus was missing its value, how wrong I was!
He left my group but stayed in touch and went to the University of Southern California where he developed his own group and network of contacts including Arthur Schawlow, with whom he worked in the University of Berkley for a while. He then moved to the University of Michigan at Ann Arbor as a full Professor and flourished through hard work and talent.
From his 400 or so publications one can see a genius at work. His mathematical models became so sophisticated they could replicate the waves on a weld pool and inside the keyhole. A far cry from where we started in 1980. He was one of the pioneers to recognise that the laser could produce nano particles through ablation at a time when no one thought nano particles would lead to much. Then came laser cladding and the realisation that cladding repeatedly in one place could build features leading to the subject of additive manufacture. Jyoti was one of the first through his contacts with Chrysler to start a company, POM, selling additive manufacturing equipment.
Together we helped another of my group, Dr Mahmoud Eboo, start a laser company, Quantum Laser, which was eventually sold to Honeywell. This company developed an expertise in cladding and 3D manufacture. He also helped me in 2010 to write the 4th edition of my book on “Laser Material Processing”, at a time when my energy was flagging!
Jyoti was a great and esteemed scientist but also a brilliant teacher. Every week he would have a seminar with his group, was always helpful to his students who became a loyal and cohesive faction in laser circles – who sometimes graciously and generously recognised me as their grandfather! There are now a number of distinguished engineers who are indebted to his care, inspiration and thoughtfulness.
At root he was a family man who was totally devoted to his wife, Aparajita and his two sons, Debashis and Debayan. His attitude to family was such that it included many of his close friends of which my wife, Margaret, and I count ourselves privileged to have been. Many others who have worked with him have lost a dear friend."
Professor Bill Steen, 20th April 2021
Read more about Jyoti Mazumder's great acievements here