Indeed, some of our recent research activities are stimulated by some specific developments in the field of physics. For example, an important trend in microelectronics and photonics is that the designs of new devices require full electromagnetic field simulations for very complicated structures. This has led to many new challenges and opportunities in our field. As a specific example, we could mention the development of photonic band-gap structures and their use in controlling light propagation. This is a new and exciting development and it has vast implications for photonics researchers and physicists. One can design and construct photonic crystals with photonic band gaps, preventing light with specific frequencies from propagating in certain directions. If one introduces a defect in a photonic crystal which has a photonic band gap, the defect will localize or guide the light whose frequency is in the gap. If it is a point defect, it can be considered as a cavity, which localizes the light.

  How important is teamwork and collaboration in achieving your goals?

Teamwork and collaboration are very important in achieving our goals. During the past 10 years, we have been collaborating fruitfully with scientists in the US, Russia, and China, for example.

With the rapid development of, for example, semiconductor manufacturing technologies and nano-technologies, photonic research becomes more and more active in smaller and smaller structures. We see such examples everywhere, from diffractive binary lenses to photonic crystals, from near-field optics of DVD to near-field scanning optical microscopy of a single molecule, and from photonic integrated circuits to photonic nano-sensors. When the feature size of a structure is comparable with or smaller than the wavelength, classical optics fails or cannot give a reliable answer and we have to use electromagnetic wave theory to deal with these photonic problems. In the coming 10 years, we believe more and more photonic research activities will require multi-disciplinary knowledge of physics, electromagnetics, material science, etc.

  What were the greatest challenges for your institution in performing and presenting its work?

Generally speaking, our challenge is to produce excellent research with very limited resources. In order to stay at the forefront of research internationally, long-term funding allowing a sufficient number of gifted scientists to devote most of their time to research is essential. Thereby a reputation for the department as an attractive and exciting place to work can be maintained, so as to attract promising graduate students and young scientists, i.e. the human resources required for sustained success. Such long-term funding is increasingly difficult to obtain in Sweden at the present time and this is a key challenge for us, which has an influence on most other aspects of our activities.

Sailing He, Leader of the photonics group at  Division of Electromagnetic Theory Royal Institute of Technology Stockholm, Sweden "Changjiang Project" special professor Zhejiang University Hangzhou, Zhejiang, China

Staffan Ström, professor emeritus, Division of Electromagnetic Theory Royal Institute of Technology Stockholm, Sweden