I worked closely with him for over 35 years, as a colleague and friend
I completed a few research projects with him, and for about a decade he was the Chair of the Physics Department and I was the Assistant Chair.
He taught me to operate under the following principles:
Len grew up in New York City, and graduated in Chemical Engineering from City College of New York, after serving in the army in World War II. His family circumstances must have been quite modest, although he didn't dwell on it. He once said that he went to college for 25 cents a day, counting the trip back and forth on the subway and a sandwich at a Deli.
He worked at Argonne after graduation, and began taking courses at IIT in the evening --- getting first the Masters Degree in Chemical Engineering, and then the PhD in Physics. He became disenchanted with Argonne. [The precipitating event may have been an occasion in which several of them were sent into a "hot" room for 15 second intervals to clean up a bad radioactive spill.] Len began teaching evening courses at IIT, and eventually came here as a full-time faculty member. He said that
Len married Bess in 1951, and first of his four children came a few years later. After scrimping for many years they bought a home in Oak Park. Len once said that they had saved enough money for him to buy a good new suit, and he went with Bess to the store to try it on. Len sent Bess back to the store to buy the suit, because he just couldn't stand to spend so much money.
Len began a research program at IIT on the study of color centers, produced in alkali halides through radiation damage, with support from the AEC [now DOE]. After about 15 years the research support was abruptly terminated.
This experience of losing research support in mid-career is frequently catastrophic, but Len felt in retrospect that it was "the best thing that could have happened". He began to employ photophysical techniques in a more general context, studying fast transient reactions in biological materials, using his home grown equipment and his expertise in a different context. He began to study biochemistry and to build scale models of biological materials, and obtained DOE support.
In the 1980's he began a quantitative analysis of radiation damage of visible laser light on biological materials, first starting with "hamburger" and "potato" as model materials, and then working on to animal and human tissue. He worked with a research group at Ravenswood Hospital on dosimetry in treatment of tumors using Photodynamic Therapy. Their technique was approved for clinical trials for inoperable throat and neck tumors, and then more generally. Len retired from IIT in 1995, but continued working on Photodynamic Therapy. Also, he wrote a textbook on Photophysics. When I last saw him a few weeks before his death, he described a wide spectrum of future research activities.
With him the family always came first --- as may be atypical for successful scientists. He also developed strong bonds with his students and colleagues, and helped to get them launched in research careers. After a certain point, he knew that they must make it on their own.
Once, during the Kent State - Cambodia days, Len saved the career of a promising young colleague at IIT. That person had written a resignation letter, because of anger and frustration. Len convinced him to reconsider his resignation, and protected him from people who wanted to push him out. This man did world-class research for the next 15 years at IIT. I doubt that Len was sympathetic with his colleague's political views, but he responded to a higher principle; namely, the dedication of a scientist to the pursuit of knowledge.
Len was proud of his accomplishments as a scientist. He felt that it would not have been likely for a guy who graduated from night school to do as well as he had done. He made his career out of the opportunities that he found for himself; he thrived in an environment that others might have found too difficult.
We will all miss him.