C17 Report

Report to the 2002 General Assembly for 1999-2002
Berlin, Germany
October 7-12, 2002

Activities

The mandate of the C17 Commission on Quantum Electronics encompasses activities aimed at promoting the exchange of information and views among the members of the international scientific community in the general field of quantum electronics, which includes the physics of coherent electromagnetic energy generation and transmission, the physics of interaction of coherent electromagnetic radiation with matter, and the application of quantum electronics to technology. The field is sufficiently broad to include a large variety of interests in both scientific and technological as well as geographical sense. The membership of C17 tries to balance this diversity of interests.

In the past three years most of the work of the Commission was done by e-mail contacts, although some members of the Commission had opportunity to meet at the conferences sponsored by C17 Commission. Different interests of particular members of the Commission, however, makes it difficult to collect most of them at one particular conference.

In years 2000-2002 five international conferences were recommended by C17 Commission and obtained financial support from IUPAP. In this respect, the situation was similar to the previous three-year term, when five conferences and one school were sponsored. The conferences sponsored in the term 1999-2002 were as follows:

• XVII International Conference on Raman Spectroscopy (ICORS’2000), Beijing, P R China, August 20–25, 2000.
• Seventh International Conference on Squeezed States and Uncertainty Relations (ICSSUR’2001), Boston, MA, USA, June 4–8, 2001.
• 17th International Conference on Coherent and Nonlinear Optics (ICONO’2001), Minsk, Belarus, June 28–July 1, 2001.
• International Quantum Electronics Conference (IQEC/LAT2002), Moscow, Russia, June 22–27, 2002.
• 9th Conference of Laser Applications in Life Sciences, (LALS 2002) Vilnius, Lithuania, July 7–11, 2002.

However, it is our feeling that in the field of quantum electronics IUPAP’s or C17’s influence in the conference domain is waning. This is because of the growth of several societies, such as Optical Society of America, SPIE – The Optical Engineering Society, IEEE – Lasers and Electro-Optics Society, which are focused in quantum electronics and also sponsor large number of conferences. As a result, the conferences sponsored by C17 are the A-type conferences outside North America and Western Europe and B-type conferences. This puts us out of the mainstream of the quantum electronics community, but we still can support conferences in less developed countries. In 2002 we, nonetheless, sponsored IQEC Conference, which is probably one of the major events in the field of quantum electronics and this time was held in Moscow.

Developments in the Field

Quantum electronics is a continuously growing field in a sense of basic research as well as applications. The international conferences sponsored by the C17 commission provided a suitable forum for discussion of the most recent advances and the perspectives in the field. Let us discuss some major developments:

There is a continuous progress in development of new lasers. This includes the ultra high power lasers, X-ray and VUV laser, blue diode lasers, mode-locked quantum cascade lasers in the infrared, organic and organo-metallic lasers, ultra-short-pulse lasers, ceramic lasers, fiber and waveguide lasers, quantum dot lasers, etc.

Ultra fast nonlinear optics approaches the barrier of the attosecond pulses.

Rapid progress is observed in constructing sources of non-classical light, such as squeezed light or entangled states. Applications of non-classical light range from super-resolution microscopy or high-resolution spectroscopy to quantum information processing or quantum cryptography. Quantum cryptography allows already for safe exchange of cryptographic keys using commercial fibers on distances over 80 km.

Quantum interference phenomena have been observed for objects as big as C60 and C70 molecules.

New technique of fabrication of photonic crystals made out of silica spheres has been proposed. It opens a possibility to produce 3-D photonic crystals with complete band gaps which would find numerous applications in telecommunication.

Lasers find new applications in processing advanced materials contributing to laser micro-technology or laser controlled nanotechnology.

Progress is made in optical tomography of biological tissues.

Femtosecond light pulses are used in ultra-fast chemistry and biology.

The permanent progress observed in the field of quantum electronics justifies the existence of the Quantum Electronics Commission in IUPAP. In terms of subject area the C17 Commission is related to the C15 Commission and the Affiliated Commission AC-1 of International Commission on Optics. The cooperation between them should be continued.

Ryszard Tanas, Secretary of the Commission

The international meetings sponsored by the Commission have been very effective in gathering a high number of experts, and in providing them a suitable forum where to discuss the most recent advances and the perspectives of a continuously growing field.

Let us very briefly consider some of the hot topics:

R&D of novel or advanced laser sources

An important trend in quantum electronics has been the development of increasingly robust and practical sources of coherent radiation. This aim has been made possible by the recent advances in diode laser technology, solid state laser technology, and nonlinear frequency conversion.

Diode laser output powers have been increasing, as has the range of room temperature operating wavelengths, extending on one side towards the UV (e.g. GaN blue diode lasers) and on the other side into the mid-IR (both quantum cascade and more traditional semiconductor lasers have been developed). Injection diode lasers in the GaN system have been demonstrated, and products are expected to appear on the market in a short term. The high-power near-IR diodes have also enabled the development of other devices, like the fiber lasers (with outputs in excess of 10 W) and the multiwatt green and blue sources, constituted by diode-pumped frequency-doubled solid-state lasers, such as frequency-doubled Nd:YAG or Nd:YVO4.

Solid-state lasers continue to be object of R&D for generation of new wavelengths or as drivers of nonlinear optical converters, such as optical parametric oscillators. An increasing attention is being focused onto rare-earth-doped integrated optical devices (in glass, lithium niobate or silicon material systems), having in mind the development of advanced components especially for optical telecom systems.

Novel light emitting materials, such as nanoporous or amorphous silicon, photoluminescent polymers, and room temperature operating tunable lasers based on color centers in fluorides are also being explored.

Ultrashort-pulse lasers and nonlinear optics

The advances in laser technology, in turn, have fueled rapid progress in more basic research. A wide range of practical picosecond/femtosecond laser systems, enabled by nonlinear optical effects, have been demonstrated; record ultrafast pulses and their extension into the deep UV, which allow us to observe extremely high-order nonlinear effects, have represented important recent achievements.

Developments of nonlinear optics have included for example the generation of squeezed states photons, the exploitation of quantum coherence effects to obtain lasing without inversion and electromagnetically induced transparency, and the use of transverse effects to achieve optical switching by spatial solitons. Quantum mechanical aspects of laser beam propagation, and the role of local field effects in dense atomic media have also been the subject of investigations. Cooling and trapping of ions and neutral atoms also continue to hold special interest to this scientific community.

Much work is being devoted to the study of the nonlinear properties of nanostructured materials, including photonic band gap materials, or photonic crystals, nanocomposite materials, and quasi-phase matched materials for efficient second-order nonlinear effects.

It is clear that ultrafast and nonlinear optics have an important synergy that will benefit both fields in the future.

Laser and ultrafast-laser applications

Many industrial applications are taking advantage of the higher variety, higher power, higher compactness and ruggedness of recently developed laser sources. These “industrial-quality” lasers are opening up new manufacturing, metrologic and medical applications.

Near-IR laser diodes and amplifiers are of great importance in optical communications systems, where ultrafast optical technologies may be used to provide new kinds of capabilities.

The availability of LEDs, ELEDs and LDs in an increasingly wide wavelength range enables the development of effective and rugged optical sensors, while high-power solid state lasers are the core of remote sensing systems (e.g. LIDARs).

The use of ultrafast tools in biological imaging, material removal for precision machining and medical applications represents another area of active R&D.

Established areas of ultrafast science, such as spectroscopy, continue to provide important insights into the physics and chemistry of fundamental processes. In particular, ultrafast spectroscopy has provided a wealth of new information about the dynamics and function of many biological systems.

The recent demonstrations of quantum teleportation, still using ultrafast technology, definitely are among the most exciting new applications in basic science.

Other exciting new topics in technology are concerned with the generation of extreme ultra-violet (XUV) and/or x-ray radiation. Techniques include high harmonic generation and laser-plasma formation using ultra-intense femtosecond and nanosecond laser pulses, and x-ray generation using

femtosecond electron bunches. Nano-machining of a large variety of materials would represent a follow-up application of these new sources.

Such a vigorous situation ensures the reason for the existence of the Quantum Electronics Commission in IUPAP, and stimulates close cooperation with other Commissions, first of all with AC-1 (ICO) and C15.

Giancarlo C. Righini, Chairman righini@iroe.fi.cnr.it