Hermann Anton Haus, an Institute Professor at the Massachusetts Institute of Technology (MIT), was to have been a Keynote Speaker at the Fluctuations and Noise in Photonics and Quantum Optics Conference, from which the papers in this special issue derive. Sadly, on May 21, 2003 – less than two weeks before the conference – Professor Haus succumbed to a heart attack after arriving home in Lexington, Massachusetts, from his regular, 15-mile commute by bicycle from MIT. He was 77. Throughout his lengthy and illustrious career, Professor Haus had repeatedly and very successfully addressed problems of fluctuations and noise, with special focus on the fundamental issues that arise in quantum optics. To honour Professor Haus' legacy to our technical community, this special issue of Journal of Optics B: Quantum and Semiclassical Optics is dedicated to his memory. Professor Haus was born in Ljubljana, Slovenia, in the former Yugoslavia, on 8 August 1925. After attending the Technische Hochschule, Graz, and the Technische Hochschule, Wien, in Austria, he received his Bachelor of Science degree from Union College in Schenectady, New York in 1949. In 1951, he graduated from Rensselaer Polytechnic Institute with a Master of Science in Electrical Engineering, and came to MIT, where he earned his Doctorate of Science and joined the faculty in 1954. He was promoted to Associate Professor in 1958, to Professor in 1962, and to Elihu Thomson Professor in 1973. In 1986, he was conferred the honour of Institute Professor. Professor Haus had a lifelong fascination with noise. While still an undergraduate at Union College, he became aware of Norbert Wiener's theories of statistical phenomena – the new mathematics needed to understand and quantify the random fluctuations we refer to as noise. So it was that noise theory formed the core of Professor Haus' research during the 1950s: noise in electron beams, noise in microwave amplifiers, and noise in amplifier cascades. Two of his notable achievements from that era are his elegant four-terminal impedance transformation for the treatment of noise in electron beams [1], and the single noise measure for optimizing linear amplifier cascades that he developed with Richard B Adler [2]. In 1960 the first working laser was reported, and Professor Haus' noise work shifted from microwaves to higher frequencies – light waves – and to the most fundamental source of fluctuations, the inescapable noise introduced by quantum mechanics. In 1962, he and Charles H Townes used the number-phase uncertainty principle to derive the sensitivity advantage that optical homodyne detection enjoys over optical heterodyne detection [3]. That same year he and James A Mullen tied the fundamental noise limits on linear amplification to the quadrature-noise uncertainty principle [4]. Four years later he and Charles Freed reported the first measurements of photoelectron statistics for a laser operating below and above its oscillation threshold [5]. All three of these works have continuing echoes through more recent research on the quantum theory of coherent detection, the noise limits of phase-insensitive and phase-sensitive amplifiers, and quantum noise measurements via photodetection. It took some time for laser technology to fulfil its initial promise of inexpensive, long-haul, broadband communications, and Professor Haus' work on modelocked, distributed-feedback, and soliton lasers played no small role in that development. Nevertheless, from the 1980s onward, Professor Haus' research interest returned again and again to quantum noise. In collaboration with colleagues from the Raytheon Company he showed that their ring-laser gyroscope was operating at the noise limit set by the number-phase uncertainty principle [6]. In collaboration with Nobuyuki Imoto and Yoshihisa Yamamoto from Nippon Telegraph and Telephone Research Laboratories he proposed a practical route to the quantum nondemolition (QND) measurement of photon number [7]. Together with James P Gordon he elucidated the quantum timing jitter that afflicts soliton propagation down optically-amplified fibre lines [8]. He and Masataka Shirasaki introduced the nonlinear Sagnac loop as a technique for generating squeezed states in optical fibre [9]. Together with his student Yinchieh Lai, Professor Haus established a physically-motivated decomposition that accounts for the various noise contributions seen in soliton squeezing [10]. The impact of these works has continued to reverberate through more recent efforts devoted to optical QND measurements, long-haul soliton transmission systems, and Sagnac loop quantum-noise manipulation. During the last decade of Professor Haus' life, he revisited – in very modern terms – some topics that he had studied early in his career. In a collaboration between his group and researchers at Bell Laboratories he used amplified spontaneous emission noise measurements to accurately predict the performance of a 10-Gbit/s optically-preamplified receiver [11], thus reprising – in the context of broadband optical communications – issues of photodetection noise statistics that he had confronted 30 years earlier with Charles Freed. In an invited paper he described a single noise figure for amplification that is valid from radio to optical frequencies [12], i.e., in both the classical and quantum regimes, thus bringing him back, full circle, to his earliest interest in amplifier noise measures. The culmination of his life's work, however, was his book, Electromagnetic Noise and Quantum Optical Measurements. Published in 2000 [13], it is a distillation of 45 years of his research. Generations of students to come will learn quantum noise from this masterwork. Professor Haus authored or co-authored five books, published more than 300 articles, and presented his work at virtually every major conference and symposium on lasers, quantum electronics, and quantum optics around the world. He was one of very few engineers in the USA to become a member of both the National Academy of Engineering and the National Academy of Sciences. He was a Fellow of the American Academy of Arts and Sciences, the American Physical Society, the Institute of Electrical and Electronics Engineers, and the Optical Society of America. He received Guggenheim and Fulbright Fellowships and several honorary degrees, including one from the University of Vienna, and he received the Austrian government's Wittgenstein Prize for outstanding contributions to humanity. Professor Haus was selected by his MIT colleagues for the 1982–1983 James R Killian Faculty Achievement Award, the highest honour that the MIT faculty bestows. In 1984, the Optical Society of America recognized Professor Haus' contributions with its Frederic Ives Medal, the Society's highest award. In 1995, Professor Haus was awarded the National Medal of Science by President William Jefferson Clinton. In a 1998 interview, Professor Haus was asked about his philosophy of life. He replied, 'Try to do your best, because that's all part of the fun. The greatest thing is that once in a while something clicks. It happens every three of four years. It can't happen more often than that, except for some exceptional people.' Things clicked for Hermann Anton Haus. This happened not just once, not just every three or four years, but regularly and throughout his long career. He was a truly exceptional man. Jeffrey H Shapiro Massachusetts Institute of Technology, Cambridge, USA References [1] Haus H A 1955 Noise in one-dimensional electron beams J. Appl. Phys. 26 560–71 [2] Haus H A and Adler R B 1958 Optimum noise performance of linear amplifiers Proc. IRE 46 1519–33 [3] Haus H A and Townes C H 1962 Comment on `Noise in photoelectric mixing' Proc. IRE 50 1544 [4] Haus H A and Mullen J A 1962 Quantum noise in linear amplifiers Phys. Rev. 128 2407–13 [5] Freed C and Haus H A 1966 Photoelectron statistics produced by a laser operating below and above the threshold of oscillation IEEE J. Quantum Electron. QE-2 190–5 [6] Dorschner T A , Haus H A, Holz M, Smith I W and Statz H 1980 Laser gyro at quantum limit IEEE J. Quantum Electron. QE-16 1376–9 [7] Imoto N, Haus H A and Yamamoto Y 1985 Quantum nondemolition measurement of the photon number via the optical Kerr effect Phys. Rev. A 32 2287-92 [8] Gordon J P and Haus H A 1986 Random walk of coherently amplified solitons in optical fiber transmission Opt. Lett. 11 665–7 [9] Shirasaki M and Haus H A 1990 Squeezing of pulses in a nonlinear interferometer J. Opt. Soc. Am. B 7 30–4 [10] Haus H A and Lai Y 1990 Quantum theory of soliton squeezing: a linearized approach J. Opt. Soc. Am. B 7 386–92 [11] Wong W S, Haus H A, Jiang L A, Hansen P B and Margalit M 1998 Photon statistics of amplified spontaneous emission noise in a 10-Gbit/s optically preamplified direct-detection receiver Opt. Lett. 23 1832–34 [12] Haus H A 2000 Noise figure definition valid from RF to optical frequencies IEEE J. Sel. Topics Quantum Electron. 6 240–7 [13] Haus H A 2000 Electromagnetic Noise and Quantum Optical Measurements (Berlin: Springer)
Hermann Anton Haus, an Institute Professor at the Massachusetts Institute of Technology (MIT), was to have been a Keynote Speaker at the Fluctuations and Noise in Photonics and Quantum Optics Conference, from which the papers in this special issue derive. Sadly, on May 21, 2003 – less than two weeks before the conference – Professor Haus succumbed to a heart attack after arriving home in Lexington, Massachusetts, from his regular, 15-mile commute by bicycle from MIT. He was 77. Throughout his lengthy and illustrious career, Professor Haus had repeatedly and very successfully addressed problems of fluctuations and noise, with special focus on the fundamental issues that arise in quantum optics. To honour Professor Haus' legacy to our technical community, this special issue of Journal of Optics B: Quantum and Semiclassical Optics is dedicated to his memory. Professor Haus was born in Ljubljana, Slovenia, in the former Yugoslavia, on 8 August 1925. After attending the Technische Hochschule, Graz, and the Technische Hochschule, Wien, in Austria, he received his Bachelor of Science degree from Union College in Schenectady, New York in 1949. In 1951, he graduated from Rensselaer Polytechnic Institute with a Master of Science in Electrical Engineering, and came to MIT, where he earned his Doctorate of Science and joined the faculty in 1954. He was promoted to Associate Professor in 1958, to Professor in 1962, and to Elihu Thomson Professor in 1973. In 1986, he was conferred the honour of Institute Professor. Professor Haus had a lifelong fascination with noise. While still an undergraduate at Union College, he became aware of Norbert Wiener's theories of statistical phenomena – the new mathematics needed to understand and quantify the random fluctuations we refer to as noise. So it was that noise theory formed the core of Professor Haus' research during the 1950s: noise in electron beams, noise in microwave amplifiers, and noise in amplifier cascades. Two of his notable achievements from that era are his elegant four-terminal impedance transformation for the treatment of noise in electron beams [1], and the single noise measure for optimizing linear amplifier cascades that he developed with Richard B Adler [2]. In 1960 the first working laser was reported, and Professor Haus' noise work shifted from microwaves to higher frequencies – light waves – and to the most fundamental source of fluctuations, the inescapable noise introduced by quantum mechanics. In 1962, he and Charles H Townes used the number-phase uncertainty principle to derive the sensitivity advantage that optical homodyne detection enjoys over optical heterodyne detection [3]. That same year he and James A Mullen tied the fundamental noise limits on linear amplification to the quadrature-noise uncertainty principle [4]. Four years later he and Charles Freed reported the first measurements of photoelectron statistics for a laser operating below and above its oscillation threshold [5]. All three of these works have continuing echoes through more recent research on the quantum theory of coherent detection, the noise limits of phase-insensitive and phase-sensitive amplifiers, and quantum noise measurements via photodetection. It took some time for laser technology to fulfil its initial promise of inexpensive, long-haul, broadband communications, and Professor Haus' work on modelocked, distributed-feedback, and soliton lasers played no small role in that development. Nevertheless, from the 1980s onward, Professor Haus' research interest returned again and again to quantum noise. In collaboration with colleagues from the Raytheon Company he showed that their ring-laser gyroscope was operating at the noise limit set by the number-phase uncertainty principle [6]. In collaboration with Nobuyuki Imoto and Yoshihisa Yamamoto from Nippon Telegraph and Telephone Research Laboratories he proposed a practical route to the quantum nondemolition (QND) measurement of photon number [7]. Together with James P Gordon he elucidated the quantum timing jitter that afflicts soliton propagation down optically-amplified fibre lines [8]. He and Masataka Shirasaki introduced the nonlinear Sagnac loop as a technique for generating squeezed states in optical fibre [9]. Together with his student Yinchieh Lai, Professor Haus established a physically-motivated decomposition that accounts for the various noise contributions seen in soliton squeezing [10]. The impact of these works has continued to reverberate through more recent efforts devoted to optical QND measurements, long-haul soliton transmission systems, and Sagnac loop quantum-noise manipulation. During the last decade of Professor Haus' life, he revisited – in very modern terms – some topics that he had studied early in his career. In a collaboration between his group and researchers at Bell Laboratories he used amplified spontaneous emission noise measurements to accurately predict the performance of a 10-Gbit/s optically-preamplified receiver [11], thus reprising – in the context of broadband optical communications – issues of photodetection noise statistics that he had confronted 30 years earlier with Charles Freed. In an invited paper he described a single noise figure for amplification that is valid from radio to optical frequencies [12], i.e., in both the classical and quantum regimes, thus bringing him back, full circle, to his earliest interest in amplifier noise measures. The culmination of his life's work, however, was his book, Electromagnetic Noise and Quantum Optical Measurements. Published in 2000 [13], it is a distillation of 45 years of his research. Generations of students to come will learn quantum noise from this masterwork. Professor Haus authored or co-authored five books, published more than 300 articles, and presented his work at virtually every major conference and symposium on lasers, quantum electronics, and quantum optics around the world. He was one of very few engineers in the USA to become a member of both the National Academy of Engineering and the National Academy of Sciences. He was a Fellow of the American Academy of Arts and Sciences, the American Physical Society, the Institute of Electrical and Electronics Engineers, and the Optical Society of America. He received Guggenheim and Fulbright Fellowships and several honorary degrees, including one from the University of Vienna, and he received the Austrian government's Wittgenstein Prize for outstanding contributions to humanity. Professor Haus was selected by his MIT colleagues for the 1982–1983 James R Killian Faculty Achievement Award, the highest honour that the MIT faculty bestows. In 1984, the Optical Society of America recognized Professor Haus' contributions with its Frederic Ives Medal, the Society's highest award. In 1995, Professor Haus was awarded the National Medal of Science by President William Jefferson Clinton. In a 1998 interview, Professor Haus was asked about his philosophy of life. He replied, 'Try to do your best, because that's all part of the fun. The greatest thing is that once in a while something clicks. It happens every three of four years. It can't happen more often than that, except for some exceptional people.' Things clicked for Hermann Anton Haus. This happened not just once, not just every three or four years, but regularly and throughout his long career. He was a truly exceptional man. Jeffrey H Shapiro Massachusetts Institute of Technology, Cambridge, USA References [1] Haus H A 1955 Noise in one-dimensional electron beams J. Appl. Phys. 26 560–71 [2] Haus H A and Adler R B 1958 Optimum noise performance of linear amplifiers Proc. IRE 46 1519–33 [3] Haus H A and Townes C H 1962 Comment on `Noise in photoelectric mixing' Proc. IRE 50 1544 [4] Haus H A and Mullen J A 1962 Quantum noise in linear amplifiers Phys. Rev. 128 2407–13 [5] Freed C and Haus H A 1966 Photoelectron statistics produced by a laser operating below and above the threshold of oscillation IEEE J. Quantum Electron. QE-2 190–5 [6] Dorschner T A , Haus H A, Holz M, Smith I W and Statz H 1980 Laser gyro at quantum limit IEEE J. Quantum Electron. QE-16 1376–9 [7] Imoto N, Haus H A and Yamamoto Y 1985 Quantum nondemolition measurement of the photon number via the optical Kerr effect Phys. Rev. A 32 2287-92 [8] Gordon J P and Haus H A 1986 Random walk of coherently amplified solitons in optical fiber transmission Opt. Lett. 11 665–7 [9] Shirasaki M and Haus H A 1990 Squeezing of pulses in a nonlinear interferometer J. Opt. Soc. Am. B 7 30–4 [10] Haus H A and Lai Y 1990 Quantum theory of soliton squeezing: a linearized approach J. Opt. Soc. Am. B 7 386–92 [11] Wong W S, Haus H A, Jiang L A, Hansen P B and Margalit M 1998 Photon statistics of amplified spontaneous emission noise in a 10-Gbit/s optically preamplified direct-detection receiver Opt. Lett. 23 1832–34 [12] Haus H A 2000 Noise figure definition valid from RF to optical frequencies IEEE J. Sel. Topics Quantum Electron. 6 240–7 [13] Haus H A 2000 Electromagnetic Noise and Quantum Optical Measurements (Berlin: Springer)
This Special Issue of Journal of Optics B: Quantum and Semiclassical Optics brings together the contributions of various researchers working on theoretical and experimental aspects of fluctuational phenomena in photonics and quantum optics. The topics discussed in this issue extend from fundamental physics to applications of noise and fluctuational methods from quantum to classical systems, and include: • Quantum measurement • Quantum squeezing • Solitons and fibres • Gravitational wave inferometers • Fluorescence phenomena • Cavity QED • Photon statistics • Noise in lasers and laser systems • Quantum computing and information • Quantum lithography • Teleportation.
With this special issue, Journal of Optics B: Quantum and Semiclassical Optics contributes to the celebration of the World Year of Physics held in recognition of five brilliant papers written by Albert Einstein in 1905. There is no need to explain to the readers of this journal the content and importance of these papers, which are cornerstones of modern physics. The 51 contributions in this special issue represent current trends in quantum optics —100 years after the concept of light quanta was introduced. At first glance, in his famous papers of 1905, Einstein treated quite independent subjects—special relativity, the nature and statistical properties of light, electrodynamics of moving bodies and Brownian motion. We now know that all these phenomena are deeply related, and these relations are clearly shown in many papers in this issue. Most of the papers are based on the talks and poster contributions from participants of the 9th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'05), which took place in Besançon, France, 2–6 May, 2005. This was the continuation of a series of meetings, originating with the first workshops organized by Professor Y S Kim at the University of Maryland, College Park, USA, in 1991 and by Professor V I Man'ko at the Lebedev Physical Institute, Moscow in 1992. One of the main topics of ICSSUR'05 and this special issue is the theory and applications of squeezed states and their generalizations. At first glance, one could think that this subject has no relation to Einstein's papers. However, this is not true: the theory of squeezed states is deeply related to special relativity, as far as it is based on the representations of the Lorentz group (see the paper by Kim Y S and Noz M E, S458–S467), which also links the current concepts of entanglement and decoherence with Lorentz-covariance. Besides, studies of the different quantum states of light imply, after all, the study of photon (or photo-electron) statistics and fluctuations of the electromagnetic field, whose importance was first emphasized by Einstein in 1905. The squeezed states can also be considered as a generalization of the concept of coherent states, which turned out to be one of the most important theoretical tools for solving the numerous problems of quantum optics. It seems highly symbolical that the printed version of this special issue will appear in the same month when one of the prominent creators of the theory of coherent states and modern quantum optics—Professor Roy J Glauber—will receive his Nobel Prize in Stockholm. ICSSUR'05 was opened by the invited talk of R J Glauber, `What makes a quantum jump?', and we take great pleasure in congratulating him on this well deserved award. We are sure that all participants of ICSSUR'05 and all readers of this special issue share our feelings. Two other Nobel Prize winners of 2005—Professor J L Hall and Professor T W Hänsch—also made great contributions to quantum optics. In particular, in 1986, J L Hall with collaborators, performed the first experiments on the generation of squeezed states by parametric down conversion, having obtained squeezing at the 50\% level (Wu L A, Kimble H J, Hall J L and Wu H 1986 Phys. Rev. Lett. 57 2520). Another area, which has attracted the attention of many researchers in the past decade and which is well represented in this special issue, is related to the problems of quantum correlations, entanglement and quantum nonlocality. It is also connected with the name of Einstein due to his famous `EPR' paper of 1935 written together with Podolsky and Rosen. For several decades this was an area of `thought experiments' only, but now this field is becoming a new part of physics, known as `quantum information'. The reader can find several papers which introduce new concepts in this area, such as applications of the Galois algebras and discrete Wigner functions. Solutions of different problems of the interaction between light and matter (which also take their origin in Einstein's paper of 1905), stationary and nonstationary Casimir effect, decoherence, new forms of uncertainty relations and their experimental verification, etc, can also be found in this issue. Many other contributions will be published in another special issue of the International Journal of Modern Physics B entitled `Quantum Information in Modern Optics'. This special issue is also the last issue of Journal of Optics B: Quantum and Semiclassical Optics. For the past 15 years this journal and its predecessors—Quantum Optics and Quantum and Semiclassical Optics—gained great respect among the quantum optics community. Many breakthrough papers were published in its pages during this period (see, for example, Schrade G, Man'ko V I, Schleich W P and Glauber R J 1995 Wigner Functions in the Paul trap Quantum Semiclass. Opt. 7 307). Since 1999, Journal of Optics B: Quantum and Semiclassical Optics has published a special issue for each ICSSUR meeting. This is the fourth issue of this series. We would like to thank Institute of Physics Publishing and the staff of Journal of Optics B: Quantum and Semiclassical Optics for providing the opportunity to pursue this programme, hoping that such a cooperation will continue in the future. We would also like to thank the many colleagues, who served as referees and whose efforts helped immensely in the preparation of this issue at such a high standard. The 10th ICSSUR conference will be organized for 2007 in Bradford, UK, by Professor A Vourdas. We invite readers to join us in two years.
With this special issue, Journal of Optics B: Quantum and Semiclassical Optics contributes to the celebration of the World Year of Physics held in recognition of five brilliant papers written by Albert Einstein in 1905. There is no need to explain to the readers of this journal the content and importance of these papers, which are cornerstones of modern physics. The 51 contributions in this special issue represent current trends in quantum optics —100 years after the concept of light quanta was introduced. At first glance, in his famous papers of 1905, Einstein treated quite independent subjects—special relativity, the nature and statistical properties of light, electrodynamics of moving bodies and Brownian motion. We now know that all these phenomena are deeply related, and these relations are clearly shown in many papers in this issue. Most of the papers are based on the talks and poster contributions from participants of the 9th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'05), which took place in Besancon, France, 2–6 May, 2005. This was the continuation of a series of meetings, originating with the first workshops organized by Professor Y S Kim at the University of Maryland, College Park, USA, in 1991 and by Professor V I Man'ko at the Lebedev Physical Institute, Moscow in 1992. One of the main topics of ICSSUR'05 and this special issue is the theory and applications of squeezed states and their generalizations. At first glance, one could think that this subject has no relation to Einstein's papers. However, this is not true: the theory of squeezed states is deeply related to special relativity, as far as it is based on the representations of the Lorentz group (see the paper by Kim Y S and Noz M E, S458–S467), which also links the current concepts of entanglement and decoherence with Lorentz-covariance. Besides, studies of the different quantum states of light imply, after all, the study of photon (or photo-electron) statistics and fluctuations of the electromagnetic field, whose importance was first emphasized by Einstein in 1905. The squeezed states can also be considered as a generalization of the concept of coherent states, which turned out to be one of the most important theoretical tools for solving the numerous problems of quantum optics. It seems highly symbolical that the printed version of this special issue will appear in the same month when one of the prominent creators of the theory of coherent states and modern quantum optics—Professor Roy J Glauber—will receive his Nobel Prize in Stockholm. ICSSUR'05 was opened by the invited talk of R J Glauber, `What makes a quantum jump?', and we take great pleasure in congratulating him on this well deserved award. We are sure that all participants of ICSSUR'05 and all readers of this special issue share our feelings. Two other Nobel Prize winners of 2005—Professor J L Hall and Professor T W H\ansch—also made great contributions to quantum optics. In particular, in 1986, J L Hall with collaborators, performed the first experiments on the generation of squeezed states by parametric down conversion, having obtained squeezing at the 50\% level (Wu L A, Kimble H J, Hall J L and Wu H 1986 Phys. Rev. Lett. 57 2520). Another area, which has attracted the attention of many researchers in the past decade and which is well represented in this special issue, is related to the problems of quantum correlations, entanglement and quantum nonlocality. It is also connected with the name of Einstein due to his famous `EPR' paper of 1935 written together with Podolsky and Rosen. For several decades this was an area of `thought experiments' only, but now this field is becoming a new part of physics, known as `quantum information'. The reader can find several papers which introduce new concepts in this area, such as applications of the Galois algebras and discrete Wigner functions. Solutions of different problems of the interaction between light and matter (which also take their origin in Einstein's paper of 1905), stationary and nonstationary Casimir effect, decoherence, new forms of uncertainty relations and their experimental verification, etc, can also be found in this issue. Many other contributions will be published in another special issue of the International Journal of Modern Physics B entitled `Quantum Information in Modern Optics'. This special issue is also the last issue of Journal of Optics B: Quantum and Semiclassical Optics. For the past 15 years this journal and its predecessors—Quantum Optics and Quantum and Semiclassical Optics—gained great respect among the quantum optics community. Many breakthrough papers were published in its pages during this period (see, for example, Schrade G, Man'ko V I, Schleich W P and Glauber R J 1995 Wigner Functions in the Paul trap Quantum Semiclass. Opt. 7 307). Since 1999, Journal of Optics B: Quantum and Semiclassical Optics has published a special issue for each ICSSUR meeting. This is the fourth issue of this series. We would like to thank Institute of Physics Publishing and the staff of Journal of Optics B: Quantum and Semiclassical Optics for providing the opportunity to pursue this programme, hoping that such a cooperation will continue in the future. We would also like to thank the many colleagues, who served as referees and whose efforts helped immensely in the preparation of this issue at such a high standard. The 10th ICSSUR conference will be organized for 2007 in Bradford, UK, by Professor A Vourdas. We invite readers to join us in two years.