Angela Guzman reflects on Denardo's influence in Latin America, and explains TSOSA's commitment to ensuring that his legacy in the field of optics continues.

I received word of Gallieno Denardo's death with a profound feeling of loss and grief. He had a tremendous influence on my development as a scientist and as a professional, and had also, over a 20 year period, grown to be a good friend. I know that he had a similar influence on many other researchers and students from developing countries, who benefited from his gentle guidance and from the programmes in optics that he fashioned.

My memories of Denardo's many achievements centre largely on the great influence that he had on the development and growth of research in optics in Latin America. What has become RIAO/OPTILAS, the principal international conference on optics in the Iberian-American region, was conceived in the early 1980s at the ICTP, where Latin-American physicists had the opportunity to meet and learn about the work of colleagues from their neighbouring countries. Long before the now-international optical societies were pursuing international outreach, the ICTP supported their initiative and helped to fund the first Latin-American Meeting on Lasers (later OPTILAS), which was held in Medellin, Colombia, in 1984.

After assuming responsibility for the ICTP's activities in optics in 1986, Denardo became a strong advocate of Latin-American initiatives and strongly supportive of OPTILAS. Through his involvement in the organization of a series of conferences on fibre optics at the ICTP, he established contact with leading Brazilian scientists involved in the successful development of the communications industry in Brazil, along with Italian and other European industries and research institutes, to prepare scientists and engineers from developing countries for optical fibre research and, at a minimum, to be educated consumers of the technology.

Denardo also organized workshops on lasers at the ICTP, where attendees had the opportunity to do experiments in the the ICTP Laser Lab that he built with donations and support from prestigious European labs. Gallieno supported an Argentinean initiative to create the Multipurpose Optical Network, which, through travel grants from the Third World Academy of Sciences, favours scientific collaboration between Latin-American researchers.

On the occasion of the merging of OPTILAS with RIAO (the Iberoamerican Conference on Optics, created by the Spanish in 1992), Denardo again played a decisive role by introducing me to Anna Consortini, then ICO's past-president and, in his words, his "good friend". She advised me on the intricacies of international conference schedules, international support and diplomacy. Denardo's long-term support of the development of optics in Latin America was recognized formally by the Latin-American optics community at the general assembly of RIAO/OPTILAS in Margarita, Venezuela, in 2004. It was at that meeting that the conference series also welcomed its first Nobel prize laureate lecturer, Claude Cohen-Tannoudji.

Denardo was a strong advocate of Latin-American initiatives in optics.

Scientific isolation
It is difficult to imagine now the scientific isolation that researchers in developing countries experienced before the internet age, but for many of us the ICTP and the Winter Colleges presented the only opportunity to keep up to date and to establish international collaborations, because our home institutions could not pay for our attendance at international conferences or for subscriptions to scientific journals. The ICTP library was an invaluable resource for our research and teaching activities, and I still remember Denardo's happiness not so long ago when the Optical Society of America offered free access to its journals for the ICTP Winter School participants for the duration of the school.

Many of us appreciated both the understanding and the encouragement that Denardo gave us when we experienced difficult family situations, as well as his warm congratulations when we achieved professional success or celebrated happy family events. Many of the participants in his early programmes became senior researchers and internationally recognized scientists. Helped by his efforts and those of the ICTP, many of us feel like members of a large international family of optics researchers, sharing a common reference point rather than operating as isolated individuals.

The TSOSA Advisory Group was established in 2003 with the aim of advising the ICTP in the area of optics activities. The members of that group, many of whom represent the major international scientific and technical societies and organizations concerned with optics, care deeply about what Gallieno Denardo achieved on behalf of optics, and are committed to seeing that his achievements survive him and that generations to come can benefit from his legacy.

Angela M Guzman, TSOSA chair, ICO vice-president.