Charles Schmuttenmaer

In 2020 we received the sad news of the passing of our friend and colleague, Professor Charles Schmuttenmaer of Yale University, New Haven, CT, USA, on Monday, July 26, 2020.

Charles (Charlie) Schmuttenmaer was born on August 5, 1963, in Oak Park, IL. He received his bachelor’s degree in Chemistry in 1985 from the University of Illinois, Urbana–Champaign where he began work in the far infrared (FIR) spectroscopy of gas phase rotational lines with H. S. Gutowsky. His graduate work in the R. J. Saykally group at University of California, Berkeley, included development of a side-band generation source for continuous scanning high resolution gas phase FIR spectroscopy. After his PhD in 1991, Charlie did postdoctoral work with R. J. D. Miller at the University of Rochester working on ultrafast solid state photoemission. He joined the Yale Chemistry faculty in 1994 and immediately employed his expertise in FIR and ultrafast spectroscopy to build a world-renowned program in terahertz time domain spectroscopy (THz TDS).

He initially focused on studies of polar solvents, binary mixtures and nano-confined water. He developed the variable path length solution cell, which has proven indispensable to achieve high precision complex dielectric response measurements for strongly absorbing solvents. In pursuit of measuring solvent reorganization about a solute after electron transfer, Charlie began working on time resolved terahertz spectroscopy (TRTS). This work led to his developing a method to deconvolve the overlap between the pump pulse and THz probe pulse to attain the earliest photo-induced response. Using this analysis, he reported the first ps time-resolved frequency-dependent complex conductivity measurements using TRTS. Upon subjecting this data to a number of modelling approaches, he found that the newly proposed Drude–Smith model was the most successful, and it has since become the standard for interpretation of THz transient photoconductivity.

Charlie’s command of both measurement and theory enabled him to show through a series of molecular crystal measurements that the character of the atomic displacements associated with the THz absorption lines progressed from strongly intermolecular to intramolecular. He established THz polarimetry techniques and analysis using cleverly designed chiral metamaterials. Charlie’s most recent scientific passion was to apply TRTS to photovoltaic materials and was a founding member of the Yale Green Energy Consortium.

It is not possible to list all of Charlie’s scientific achievements. These are reflected in his various awards and fellowships in the Royal Society, the APS and the AAAS. Beyond this, Charlie was instrumental in creating a vibrant and collegial community. From organizing innumerable international symposia and conferences, to his exuberant talks and discussions, Charlie exuded a joy for scientific exploration and life. We send our heart-felt condolences to his family.

Andrea Markelz, December 31, 2020
Moti Lal Rustgi Professor of Physics
University at Buffalo
Buffalo, NY 14260 USA

Maurice F. Kimmitt

We have just received the sad news of the passing of our friend and colleague, Professor Maurice Kimmitt, of the University of Essex.

Maurice was active for many decades in the field of infrared, millimetre and terahertz waves and his book “Far-infrared techniques”, published by Pion Ltd. in 1970, was one of the first in the field. During his long career, which began at RRE Malvern (the Royal Radar Establishment) and continued at the University of Essex, Maurice made many seminal contributions in the field, beginning with work on (TEA) CO2 lasers and the photon-drag effect in semiconductors, measurement of the optical properties, including the absorption (at saturation levels), transmission and refraction of many semiconductor materials, two-photon absorption and carrier lifetimes. Maurice also carried out a great deal of work on far infrared detectors, including photon drag, HgCdTe and Schottky diodes. Among the sources he used, investigated or developed are CO2 lasers, p-Ge lasers, Smith–Purcell emitters, and last, but not least, free electron lasers (FELs), and he was particularly active in the latter field during the later years of his career at ENEA, Frascati.

Following his retirement from the University of Essex in the late 1980s, there was a remarkable renaissance in Maurice’s career when his services were sought out internationally as a research consultant and visiting professor in research laboratories around the world. These included appointments at the University of Buenos Aires, Dartmouth College in Hanover, New Hampshire, an Ivy League College, ENEA Frascati Research Centre, Rome (the Italian National Agency for New Technologies, Energy and Sustainable Economic Development), DLR, Berlin (the German National Aerospace Centre, and Heriot–Watt University, Edinburgh. Following the sudden tragic death of Professor John Walsh, Maurice’s colleague and collaborator at Dartmouth College in the late 1990s, leaving several graduate students stranded in the later stages of their PhD projects, Maurice spent several months in Dartmouth to support them through the final stages of their projects.

In 1998, DLR held a two-day symposium in Berlin in Maurice’s honour, and scientists came from all over the world to present papers as a tribute to him. The proceedings were published the following year in a special issue of the journal Infrared Physics and Technology. In the context of the International Series of Conferences on Infrared, Millimeter and Terahertz Waves, on the two occasions when the conference was held at the University of Essex in Colchester, Maurice was a member of the Local Organising Committee. He was awarded the Kenneth J. Button Prize for outstanding contributions to the science of the electromagnetic spectrum in 2004, and later served for a number of years on the Kenneth J. Button Prize Committee. In 2010, when the conference was held in Rome, Maurice was honoured by being appointed Honorary Chairman of the Conference.

Maurice will be greatly missed by members of the conference community, and we send our sincere condolences to his widow, Mhairi, who was well known in our community as she joined Maurice at many conferences as an accompanying person.

Terry J Parker January 24, 2020
Emeritus Professor of Physics
University of Essex
Colchester CO4 3SQ

Derek Martin

Professor Derek Martin died on 14 February 2020 aged 91. Derek was a pioneer of the study and use of the Terahertz electromagnetic spectrum. His most famous instrument, the Martin-Puplett polarising interferometer, was used by him and others in a variety of applications from measurement of the cosmic microwave background to diagnosis of plasma in nuclear fusion machines.

Derek was honorary secretary of the Institute of Physics for 10 years (1984 – 1994). He was instrumental in choosing the new chief executive and helped him to implement new strategies and transform the IOP into the influential and vigorous society, with greatly enlarged membership, that it became. He was an IOP representative at meetings of overseas national and international societies and a leader of the UK delegation to the International Union of Pure and Applied Physics. He was also editor of the journal Advances in Physics.

After obtaining a PhD from Nottingham in 1954 he came to Queen Mary College (now Queen Mary University of London) as an assistant lecturer in physics. He was promoted successively to lecturer, reader, and professor. For several years he served as head of department and later as dean of faculty. He was also a University of London senator. He was made an honorary fellow of Queen Mary in 1996.

He arrived at Queen Mary committed to a search for a better understanding of the exotic phenomena of superconductivity and of strong magnetism in solids. He decided to seek ways to generate and detect electromagnetic waves in an unexplored part of the spectrum, that between the infrared and microwaves, wavelengths around 1 mm, because he believed that such waves would probe the large-scale collective motions of atoms.

Before that could be done there were substantial technical impediments for him to overcome. One of his first steps was to build a miniature refrigerator to reach temperatures within a degree or two of absolute zero and to operate a superconducting detector at this ultra-low temperature in order to be able to detect signals of extremely low strength.

His belief was soon proved to be right and he embarked on the central-path of his scientific work: the development of ever-more subtle techniques for detecting and analysing submillimetre waves and applying them in studies of the structures of matter. This took him, and colleagues at Queen Mary, beyond solid state physics, into astronomy and cosmology, into the remote-sensing of ozone-related stratospheric chemistry from aircraft, high-altitude balloons and satellites, and into diagnostic studies of energy-generating plasma machines. His work rapidly gained wide recognition and many visitors came to Queen Mary to work with him and to learn the elegant and sensitive measurement techniques he had developed, then to return to pursue such work in their own laboratories in the USA, Japan, Australia, Canada, Italy, Germany and China.

He initiated several of the research areas in the physics department: polymer physics which grew into molecular electronics and condensed matter physics and the inventions of instruments which were developed by a company which became QMC Instruments, initially based at Queen Mary, but now at Cardiff. He also collaborated with colleagues in electrical engineering.

As a member and chairman of the Astronomy Committee of the Science Research Council through the 70s, he was one of the first to understand the importance of molecules in space and their detectability in the submillimetre wavelengths. He was centrally involved in proposing what eventually became the James Clerk Maxwell Telescope, the world’s largest and most successful submillimetre facility. This gave the UK a world-lead in the field which continues to this day.

He also initiated the participation of the UK in the first satellite-borne infrared telescope, IRAS, which revealed the rich infrared sky which had hitherto been obscured by the Earth’s atmosphere. Derek Martin invented the polarising Michelson interferometer, the Martin-Puplett design that was used successfully to make early observations of the cosmic microwave background from balloon and ground-based platforms.

Another measure of his huge legacy is that many of his colleagues at Queen Mary have been leading figures in the use of these ground-based and satellite-borne infrared and submillimetre telescopes. In addition, many of his students have gone on to occupy prestigious positions in astronomy and high-tech organisations in the UK and abroad.

Derek’s interest in instrumentation, and particularly for the experimentally difficult part of the electromagnetic spectrum where optical and radio techniques approach each other, led to millimetre-wave diplexers, power meters and other devices. These were later developed further by his students and associates who have commented that it had been a real pleasure to work with Derek, that he was always helpful and considerate, as well as being an outstanding scientist.

In recognition of the seminal importance of his work in measurement science, Derek was awarded a number of scientific prizes including the Kelvin Award of the Institute of Electrical Engineering, the Metrology Prize of the National Physical Laboratory and the Kenneth J Button Prize for pioneering terahertz polarization interferometry.

Derek spent 1966 as visiting professor at the University of California at Berkeley at the time of student unrest there. This perhaps stood him in good stead because, soon after his return, he was elected dean of the faculty of science in the college, just as the student revolts spread from the USA to universities in Europe. Queen Mary was less disrupted than many of the other leading universities here. One possible factor in this was the decision to replace the then-conventional rigid science-degree programmes with a modular science-degree geared to the developing interests of individual students. As dean for science, Derek had to find a pattern of implementation persuasive to senior and strong-minded academic colleagues across the faculty. That pattern has since spread to other faculties in the college and to many other universities.

However, notwithstanding these many and diverse activities, he remained primarily a teacher and researcher in his subject. His work has contributed substantially to the Queen Mary’s success and high international reputation.

Peter Kalmus
Queen Mary University of London


Richard Pantell

Richard H. Pantell, Professor Emeritus of Electrical Engineering at Stanford University, died March 26, 2019, at the age of 91. Richard Pantell was an outstanding scientist of extremely broad interests and knowledge. He designed novel microwave and millimeter wave devices and made remarkable contributions to Free Electron Lasers (FEL) physics and technology, as well as to nonlinear optics and infrared lasers. Richard Pantell was born in New York City on December 25th, 1927. After completing his secondary education, he enrolled in Electrical Engineering at the Massachusetts Institute of Technology, where he earned his bachelor’s and master’s degrees. He moved to Stanford in 1951, where he obtained his doctorate in 1954. He was then appointed assistant professor at Stanford and became full professor in 1964. In 1989, he became director of the multidisciplinary Ginzton Laboratory that included research groups from microwave engineering to laser physics and solid-state physics. He remained on the faculty until his retirement in 1994.

In the fifties, Richard Pantell joined the effort to develop high frequency microwave sources to reach the millimeter and submillimeter range overcoming the physical limitation in realizing resonant cavities at the fundamental frequency. This is testified by a number of high quality pioneering papers on resistive frequency multipliers, dielectric slow-wave structures, harmonic travelling wave tubes, backward wave oscillators, and the helical electron beam tube, which was a predecessor to electron cyclotron masers and gyrotrons.

With the advent of laser in 1960, Pantell and coworkers turned their attention and to the generation of sub-millimeter waves by optical methods. As early as 1962, Richard Pantell together with M. D. Domenico, J.R. Fontana and 0. Svelte published a method for generating submillimeter radiation by mixing of optical wavelengths. This method was successfully employed in single CdSe crystals and in other semiconductors. Pantell’s research on laser in the sixties covered external seeding, tunability of the Raman Laser mode coupling, non­linear absorption. In the community of terahertz parametric generation, Pantell is known as the person who discovered the so-called Stimulated Polariton Scattering (SPS) in Lithium Niobate leading to the realization of a continuously tunable submillimeter waves source. In this period, he also co-authored with H.E. Puthoff a world-famous book on the fundamentals of Quantum Electronics.

In the seventies he started a new research line on the generation of Cerenkov radiation as a light source in the optical region and in the ultraviolet. He also turned his attention to X-ray and y-ray emission from channeled relativistic electrons and positrons, which led to outstanding experimental results. Energy exchange between free electrons and an electromagnetic field became a hot topic of research again after John Madey’s first operation of the FEL. In this field too, Pantell searched for new schemes of operation, developing and successfully testing the so-called Gas Loaded FEL. As early as 1979, he published the first paper on laser-driven linear acceleration of electrons. This seminal work, reviewed in his FEL-Prize talk in 1996, set the guidelines for the design of all laser-driven linear accelerators. In FEL physics and technology Pantell also introduced the concept of optical resonators with a hole on axis to allow both outcoupling and the passage of the electron beam, and the design of a solenoid derived wiggler, which was successfully tested on a compact Far-Infrared FEL in the nineties. In this period, the coherent spontaneous emission by a bunched electron beam in FELs was also investigated. Later, he turned his interest to X-ray optics, neutron physics in materials analysis and medical applications. We are deeply grateful to Dick for his knowledge, expertise and sense of humour he shared with all his coworkers, students and friends, as well as for his legacy as a precursor in the field of infrared, millimetre and terahertz waves.

G.P. Gallerano, Y.C. Huang, J. F. Lampin, K. Mizuno, G. Neil, G. Nusinovich,
J.F. Schmerge, R. Temkin, M. Thumm
September 2019

Akiyoshi Mitsuishi

Akiyoshi Mitsuishi was born on October 15, 1925, in Taejon, South Korea. He spent his childhood and early life in Taejon, and spent high school life in Hiroshima, Japan. Then he went to Kyoto to study at Kyoto University. He received an undergraduate degree in 1948. He continued his graduate studies at Kyoto University. During the period he was particularly affected by Prof. Uchida in spectroscopy and by Prof. Yukawa, the first Nobel Prize Winner of Japan in theoretical physics. Mitsuishi joined the research staff of Osaka University in 1940, where he mainly studied the optical properties of solids working in Prof. Yoshinaga’s laboratory. Akiyoshi contributed largely to the construction of the famous Far Infrared (FIR) grating spectrometer of Osaka University. His important role was to develop optical components such as the pile-of-plates polarizer, alkali halide powder filters (so-called Yoshinaga filters) and woven metal mesh reflection filters. Yoshinaga filters are particularly useful for suppressing the higher orders of the grating and useful as cooled filters for cooled detectors. At the initial stage of FIR spectroscopy by use of this grating spectrometer, Mitsuishi and collaborators applied it to the measurements of reststrahlen bands of well-known NaCl, KCl, and KBr, at 100 K, 200 K and 300 K. He and collaborators realized that NaCl has another subpeak and KBr has also a small subpeak on the sharp rise of short wavelength side (1959) in addition to the measured results in 1930. Charles Kittel included that data in a revision of his world-famous text book ‘Introduction to Solid State Physics’. This made Mitsuishi famous world-wide. In succession he pushed forward to the study of material science in solids such as color centers in alkali halides, phase change of ferroelectric crystals, shallow impurity levels of the doped semiconductor, and localized impurity modes. His scientific activities are written in Invited Review Articles of Journal of Infrared, Millimeter, and Terahertz Waves Vol. 35 (2014) and in Infrared and Millimeter Waves (ed. K. J. Button) 16, Chap. 6 (1986).

Akiyoshi was willing to support our communities which are not only domestic but international. He was the President of a large academic community Applied Physics in Japan and in succession was a member of the most powerful academic organization, the Science Council of Japan. He was the first president of The Japan Society of Infrared Science and Technology. Internationally he was an honorable advisor of the British journal Infrared Physics and the international advisor of the Chinese journal Infrared Research.

Akiyoshi supported our conference series working as the Local Committee Chair of the Takarazuka Conference in 1984, Vice Chair of the Sendai Conference in 1994 and Honorary Chair of the Otsu Conference in 2003. He was really a great scientist and a broad-minded person.

Akiyoshi Mitsuishi was awarded ‘The Order of the Sacred Treasure, Gold Rays with Neck Ribbon’ by the Emperor as a Great Professor.

Kiyomi Sakai October 4, 2020
Research Center for Development of Far-Infrared Region
University of Fukui
Fukui, Japan

Armand Hadni

We have just received the sad news of the passing of our friend and colleague, Professor Armand Hadni of the University of Nancy, France, on Monday, August 26, 2019, at the age of 94.

Armand Hadni was born on February 17, 1925, in Paris. He received his PhD in 1955 at the Sorbonne, where there is a long tradition in optics, and especially in the infrared. Alfred Kastler and Jean Lecomte, two giants in the field, were in the Jury. Armand went on to become one of the pioneers of far infrared spectroscopy of solids, founding the Laboratory for the Far Infrared at the University of Nancy, where he was appointed Professor of Physics at a very early age. His work was focussed in two main areas, instrumentation and solid state spectroscopy.

In instrumentation, Armand studied echelette gratings and developed a small grating interferometer for the far infrared. He went on to study the fundamental role of “étendue geometrique”, or “throughput” in English, which led him to Fourier transform spectroscopy and the development of new detectors such as germanium bolometers, pyroelectric detectors and a VIDICON tube with a pyroelectric retina which was produced commercially by THOMSON-CSF.

Armand used these techniques to study a variety of solids at temperatures from 4 K to 300 K. His samples included ferroelectric crystals and high Tc superconductors, and he obtained significant new results on ferroelectric soft mode behaviour and phase transitions, Debye relaxations, surface layers and electronic transitions. In work on high Tc superconductors, he obtained new results on plasma frequencies, collision frequencies and Bose–Einstein condensation, and he developed a new phenomenological model to calculate all infrared properties from 4 K to 300 K.

In 1967 Armand published the first comprehensive book in this field, “Essentials of Modern Physics applied to the Study of the Infrared”. This was a major undertaking by any standards, an authoritative review in English of the state of the art at the time extending to 725 pages and published by Pergamon Press. In 2002 he was awarded the Kenneth J. Button Prize for outstanding contributions to the science of the electromagnetic spectrum.
Armand was also very generous with his time in supporting our community. He supported our conference series from the very start in 1974 in Atlanta, Georgia, USA, and in 1983 he was Chairman of the Programme Committee and a member of the International Committee of the 7th International Conference on Infrared and Millimetre Waves in Marseille. He went on to serve for more than 25 years on various conference committees, including the International Organising Committee, the International Advisory Committee and the Prize Committee.

Armand Hadni was a gifted scientist and a wonderful person, and he will be greatly missed by his friends and colleagues around the world. We send our sincere condolences to his wife, Francoise, who joined Armand at many of our conferences as an accompanying person, and to the rest of his family.

Terry Parker August 31, 2019
T. J. Parker Emeritus Professor of Physics
University of Essex
Colchester CO4 3SQ


T V George

Dr. T. V. George, a brilliant scientist, extraordinary leader of research on fusion energy and a wonderful friend to countless scientists in the international science community, passed away on May 10, 2015 after a long illness.

Dr. Thycodam Varkey George, known to everyone as T.V., was born in Kerala, India. He came to the United States for his graduate work, receiving the M. S. and Ph. D. degrees in Electrical Engineering from the University of Illinois, Urbana-Champaign. He served as a Professor at the Univ. Illinois before moving to Pittsburgh, Pennsylvania to become a Senior Engineer at the Westinghouse Research Laboratory. There he became interested in the rapidly-growing field of plasma physics and nuclear fusion energy. He soon took a position at the US Department of Energy (DOE) in the Washington DC area, where he served for over thirty years as a program manager. Dr. George oversaw many different research programs, but he was particularly well-known nationally and internationally for his oversight of the development of gyrotron-based, high-power Electron Cyclotron Resonance plasma heating systems. Under his leadership, the US went from developing relatively low-frequency gyrotrons at power levels of one-two hundred kilowatts to achieving megawatt power levels at the high frequencies needed for modern plasma physics research. Dr. George also served as a Program manager for fusion experiments at all size scales, from the very large to smaller, innovative confinement experiments within the US Fusion Energy Sciences Program. He retired from DOE in 2010.

Dr. George was a champion of collaboration in scientific research. He was a key member of the International Organizing Committee of this Conference from 1997 to 2012. He initiated many international exchanges, including a series of Workshops on Electron Cyclotron Heating Technology that are held directly after this Conference. Dr. George organized countless collaboration meetings between the United States and Japan, Europe, and Russia. He was on the organizing committee of the bi-annual Shenzhen Conference in China. T. V. George and his wife Achamma were gracious hosts to many visitors to the Washington, DC area for more than three decades. An invitation to the George home was a very special and festive occasion. T. V. and Achamma also traveled throughout the world, making countless friends on every continent. T.V.’s wisdom, optimism and infectious good humor will be especially remembered by the IRMMW-THz community.

Dr. T. V. George is survived by his wife, Achamma, and their three children Asha, Shobha and Sageev (wife, Donell). IOC Members – 2015


Hui-Chun Liu

Hui-Chun Liu was known for his groundbreaking work with semiconductor quantum devices, Hui-Chun Liu passed away on 23 October 2013, at age 53 in Shanghai, China; he had taken a bad fall and was in a coma the last nine days of his life. His sudden and unexpected death is a shock to the physics community.

Known to colleagues as H.C., he was born in Taiyuan, China, in 1960. He received his BSc in physics from Lanzhou University in 1982. After success-fully passing the selection process for the second-year China–US Physics Examination and Application program, H.C. went to the University of Pitts-burgh, where he received his PhD in applied physics in 1987 in the group of Daryl D. Coon. His major research interest was semiconductor nanoscience and quantum devices.

H.C. joined the Institute for Microstructural Sciences of the National Re-search Council Canada as a research associate in 1987 and rose rapidly through the ranks. In 1998 he was named to lead the council’s terahertz and imaging devices group and in 2000 he became a principal research officer – the highest rank, reserved for very few. In 2011 he returned to China to take a position at Shanghai Jiao Tong University, where as a chair professor he put together a new research group. H.C. had been recruited through the “1000 talents” program, which brings top-class minds to China from over-seas. He founded two high-tech companies in China: Debut Optoelectronic Sensors in Wuxi, and Ghopto Shanxi Guohui Optoelectronic Technology in Taiyuan.

Among H.C.’s honors were the Herzberg Medal from the Canadian Association of Physicists in 2000, the Bessel Prize from the Alexander von Humboldt Foundation in 2001, and the Jiangsu provincial high-level innovation-entrepreneur talent award in 2011. H.C. was granted more than a dozen patents, wrote or co-wrote more than 380 articles in refereed journals, and gave 95 invited presentations at international conferences. When H.C. was still in graduate school in the 1980s, the field of intersub-band transitions in semiconductor quantum wells was born. H. C. was one of the founders of the field of quantum well infrared photodetectors (QWIPs). As a junior researcher at National Research Council Canada, he started a world-leading re-search program on QWIPs. The ultrafast QWIP technologies he developed are being used in leading research laboratories and industries, including Harvard University, ETH-Zürich, and Northrop Grumman. His patented upconversion pixel-less im-agers have attracted considerable attention, as has his pioneering extension of QWIPs into the terahertz spectral region.

H.C.’s name has become synonymous with QWIP. He edited two volumes of the series Semiconductors and Semimetals and wrote a monograph on QWIPs. He served as chair or co-chair of various QWIP workshops, was twice chair of the International Conference on Intersubband Transitions in Quantum Wells, and was a member of several steering and advisory committees overseeing the strategic development of terahertz technology in China.

In addition to his laying the foundations for the field of QWIPs, H.C. demonstrated two-photon absorption in QWIPs, studied various nonlinear optical phenomena through intersubband transitions, and developed an intersubband Raman laser. Early in his career, he did innovative analysis on resonant tunneling di-odes. More recently, he was focusing on terahertz quantum cascade lasers and, with his collaborators, achieved a record-high operating temperature, which is significant, since increasing the lasers’ operating temperature is the most important challenge in the field.

H.C. was like a brother to many of his colleagues around the world. A unique leader, he was generous with and fiercely protective of his staff, was attentive to their well-being, and knew instinctively how to draw out the best skills of each team member. He instilled a sense of common purpose in all. His calm and positive demeanor greatly influenced his colleagues and especially his students.

H.C.’s unfailing support and loyalty will be deeply missed, and he will al-ways be fondly remembered.

Tucson, September 2014 Harald Schneider, Qing Hu, Emmanuel Dupont, Xi-Cheng Zhang, Chao Zhang, and Jun-Cheng Cao

Masanori Hangyo

The co-initiator and mentor of terahertz science and technology in Japan

Masanori Hangyo inspired research on terahertz (THz) science and technologies in Japan and led the THz community as a mentor of outstanding capability. Hangyo, who passed away in Osaka on October 25, 2014, was born in Toyama, Japan, in 1953 and spent his childhood and early life, up to his high school days, there. He then went to study at Kyoto University, and in 1976 received an undergraduate degree in physics. He continued his graduate studies at Kyoto University and completed his Ph.D. in 1981. After graduating from Kyoto University, Hangyo joined the research staff of Osaka University. He mainly studied the optical properties of solids there, working in Prof. A. Mitsuishi’s laboratory, which was known worldwide as a result of its spectroscopic studies on solid state materials in the far-infrared region.

Initially, Hangyo studied solids by using Raman spectroscopy. But later, he and his colleagues started studying solid materials by using far-infrared spectroscopy. They constructed a dispersive interferometer for the mm and sub-mm region consisting of a Calcinotron and multipliers as the radiation source, and a Mach-Zehnder interferometer. By using this spectrometer, Hangyo was able to measure the optical properties of some solid materials. These experiments were rather time consuming and demanding, but in 1988, he came to know of Terahertz Time Domain Spectroscopy (THz-TDS), learning about it from Dr. Sakai who excitedly told Hangyo about the THz-TDS technique reported at the IRMMW Conference that year.

In 1990, Hangyo was promoted to associate professor of the Research Center for Superconducting Materials and Electronics (RCSE) of Osaka University, when Dr. Sakai, an associate professor, took over as director of Laboratory for Quantum Electronics of the Communications Research Laboratory (CRL) (currently NICT) in Kobe. Dr. Sakai formed a THz-TDS research group at a new national research institute. The group included Hangyo and Dr. Masahiko Tani, who had just joined the CRL as a research member, and Prof. Shin-ichi Nakashima, the successor to Prof. A. Mitsuishi. Hangyo proposed the emission of THz radiation from high-Tc superconductors by irradiation using femtosecond laser pulses and succeeded in demonstrating it experimentally. Based on THz emissions from high-Tc superconductors, Hangyo went on to demonstrate the visualization of the supercurrent flow. In 1996, he was promoted to professor of the RCSE, where he formed his own THz-TDS team. Leading his group he published many excellent papers such as “Poor Man’s THz- TDS” and “Application of Alanine Spectra.” In the last 10 years of his career, Hangyo focused his interest on THz meta-materials.

In 2004, the Research Center consolidated into the Institute of Laser Engineering, where Hangyo was promoted to vice president of the Institute. He served as a steering committee member of the 182nd (THz) and the 187th (meta-material) Committee of the Japan Society for the Promotion of Science (JSPS), and he also served as the president of the THz Technology Forum in Japan from 2013. In 1996, he was awarded the Toyama Prize in Physics.

Hangyo was dearly loved by many people—from his students to senior scientists—not only because of his dedication to THz science and his significant scientific achievements, but also because of his friendly and mature personality.

Kiyomi Sakai, Masahiko Tani, Takeshi Nagashima, Makoto Nakajima
July 2015


Mario Sorolla Ayza

Mario Sorolla Ayza, a pioneer in the application of photonic band-gap structures, meta-materials, enhanced transmission phenomena and plasmonic structures to modern millimeter wave antennas and circuits, passed away on November 1st, 2012 after a cancer-related surgery in Pamplona, Spain. He was 54. The international millimeter, infrared and terahertz wave community will miss his unique and far-ranging intellect, the clarity of his thought and exceptional human qualities. During his career he published more than 150 papers, 2 books, 1 book chapter, nearly 300 conference communications (more than 30 invited) and 10 patents. Widely considered to be a maverick in academia and highly regarded for his scientific success, he also will be always remembered and respected for his visionary leadership and high ethical standards.

Born in Vinaròs at the Spanish Mediterranean coast, on October 19th, 1958, Mario earned the Telecommunication Engineer degree from the Polytechnic University of Catalonia, in Barcelona, Spain, in 1984, and the Ph.D. degree from the Polytechnic University of Madrid in Madrid, Spain, in 1991. Although during those years he devoted most of his time in an academic environment closely linked to the Euratom-Ciemat Spanish Nuclear Fusion Experiment and the Institut für Plasmaforschung (IPF) at the Stuttgart University in Stuttgart, Germany, he had already then some sporadic experiences in industry (Tagra S.A.) designing antennas and radiofrequency electronic devices for space and ground applications.

He designed monolithic microwave ICs for Satellite Communications related with the European Space Agency (ESA). At IPF Stuttgart he was from 1987 to 1988 an Invited Scientist working closely with Manfred Thumm, who left a profound mark on Mario and definitely influenced his future career. Mario was involved in the design and test of oversized waveguide components for high-power microwaves (28, 56, 70, and 140 GHz), such as non-linear diameter tapers, gradual bends, mode converters, etc., for Euratom- CIEMAT in Madrid, Spain, and the Max-Planck-Institut für Plasmaphysik, Garching, Germany.
His academic career took off in 1991 when he was appointed Director of the
Communications Engineering Department at Enginyeria La Salle, Universitat Ramón Llull in Barcelona, where he was simultaneously, Professor of Electromagnetic Fields and Waves, Microwaves, and photonics. In 1993 he joined the Universidad Pública de Navarra (UPNA), Navarre, Spain, where he was promoted to full Professor in 2001. He was Head of the Electrical and Electronic Engineering Department (2002-2005), Leader of the communications, Signal and Microwaves Research Group (2007-2012) and Principal Investigator of the Millimeter and Terahertz Waves Laboratory since its creation. His exceptional scientific career was recognized with the Research Career Award granted by UPNA in 2009.

Mario always strongly advocated technology transfer. He initiated in 2008 together with his partners a spin-off company: TAFCO Metawireless S.L. which has grown steadily since then. There Mario played a leading role with respect to the vision and strategy, positioning the company in the aerospace and energy industry. His double success in academia and business was recognized by the Asociación Navarra de Ingenieros de Telecomunicación with the Engineer of the Year 2010 Award.

Although Mario’s accomplishments are of great value to UPNA and TAFCO Metawireless S.L., it is his drive and motivation for greatness and his endless generosity that mark his indelible and everlasting legacy. No matter the complexity or magnitude of the project, he always delivered high quality results while adding his personal and unforgettable touch of kindness. Mario is survived by his wife Puri and his daughters Carolina and Viviana.

Mainz, September 2013
Miguel Beruete,
Francisco Falcone,
Miguel Navarro-Cia and
Manfred Thumm


Kenneth J. Button

Ken was born on October 11, 1922 in Rochester, New York and died on August 30, 2010 in Indialantic, Florida. Ken did undergraduate and graduate work in physics at the University of Rochester after serving for four years in the U.S. Army Infantry during WW II. He began his research career in 1952 at the newly-formed MIT Lincoln Laboratory, conducting pioneering work that led to the book Microwave Ferrites and Ferrimagnetics, co-authored with Benjamin Lax. In 1962, he helped to found the MIT National Magnet Laboratory on the MIT campus in Cambridge. In 1965, he convinced H. A. Gebbie of the NPL in the UK to bring to the MIT Magnet Lab a copy of the newly discovered 0.337 mm wavelength cyanide laser. Using that laser, Button, Gebbie and Lax collaborated to study cyclotron resonance in semiconductors at magnetic fields of up to 18 T and temperatures down to 40K. This THz laser spectrometer coupled with magnetic tuning of semiconductor bands opened up a major new field of research that led to many significant publications in the 1960s and 1970s. Ken held the position of Senior Scientist at MIT and headed the research group on quantum electronics until his retirement in 1988. Ken will be especially remembered by numerous graduate students, postdoctoral associates, research staff members and visiting scientists that he mentored during his years at MIT.

Ken had a remarkable career as a scientist and as a conference organizer, book author, book editor and journal founder/editor. Ken served six years on the IEEE-MTT Administrative Committee. He received their Distinguished Service Award in 1980 and their Certificate of Recognition in 1981. At various times, Ken was Vice-President of the IEEE Quantum Electronics Society, President of the New England Section of the Optical Society; Member of the Board of Directors of the Massachusetts Engineers’ Council; Member of the IEEE Energy Committee, and Chairman of Commission D (Physical Electronics) of the International Union of Radio Science (URSI). After serving as the Program Chairman of the first conference on “Submillimeter Waves and Their Applications” in 1974, Ken founded the continuing series of conferences (International Conference on Infrared and Millimeter Waves), serving as the General Chairman. Ken also served as the Editor of an Academic Press series of sixteen books on Infrared and Millimeter Waves. He was the Founding Editor of the International Journal of Infrared and Millimeter Waves and served as Editor from 1980 to 2004. Ken was a Fellow of the American Physical Society and the IEEE.

Ken Button, outstanding scientist, colleague and friend, will live on in the hearts and minds of those who were fortunate to have known him.

Contributed by IRMMW-THz IOC members, September 2011.