[No. 88] Juntaro Ishii

My nine years at Keio University were very meaningful, allowing me to meet wonderful mentors and friends and to discover the joy of research. It has been about 15 years since I started working at a research institute in Tsukuba, and I still often find myself looking back at my university textbooks.

I believe it was when I was in the fifth grade of elementary school that a science documentary series called "Cosmos," supervised by the American astronomer Dr. Carl Sagan, was broadcast on television. As an elementary school student, I didn't understand the scientific explanations well, but I was strongly intrigued by the diverse visuals about the "Big Bang" and the "theory of relativity." My elementary school teacher at the time told me, "If you're interested in space, you should study physics at university in the future," which gave me a vague feeling that "physics seems interesting."

In my third year of high school, I was given the chance to apply to the Keio University Faculty of Science and Technology through a designated school recommendation. When I consulted my high school physics teacher, he advised me, "Keio's Department of Physics has excellent professors," so I applied for Cluster I (Mechanical, Electrical, Instrumentation, and Physics).

The content and pace of the classes were vastly different from high school, so I was honestly quite bewildered at first. However, by teaching each other what we didn't understand with my classmates, I gradually got used to university lectures, and from my second year, I advanced to my desired Department of Physics. For extracurricular activities, I was invited to join the Faculty of Science and Technology Athletic Association Swimming Club (Gin-ei Kai), being told, "Swimming will help you lose weight." My routine involved attending morning practice at a swimming club near the university several times a week before heading to my classes. Perhaps because I wasn't a very dedicated member, the diet had no effect, and unfortunately, my weight has been "monotonically increasing" ever since.

When I became a third-year student and moved from Hiyoshi to the Yagami Campus, lectures in the Department of Physics became the main focus, and I felt that both the quality and quantity of the classes had leveled up. In physics experiments, in particular, we sometimes worked late into the evening and struggled with writing reports. The Department of Physics had a small class size of about 45 students per year, creating an atmosphere like a single class in middle or high school, which brought us much closer to the professors. For my research lab assignment upon entering my fourth year, I chose Professor Uehara's laboratory in "Laser Spectroscopy." Under the guidance of Professor Uehara and Professor Sasada, I conducted my graduation research on the theme of "Noise Spectroscopy of Semiconductor Lasers." Although it was called "research," at the time I barely knew my left from my right. I was doing all I could just to build experimental apparatuses using lathes and drill presses and to conduct experiments as instructed by my professors. Before I knew it, my graduation research was over.

In graduate school, I continued to belong to Professor Uehara's laboratory. However, I began to work on laser spectroscopy research of highly excited molecules in the vacuum ultraviolet and extreme ultraviolet regions at the Microwave Physics Laboratory of RIKEN (Wako, Saitama), which had a collaborative relationship with the Uehara lab. I worked under the guidance of principal investigator Kasuya and researcher Tsukiyama. At that time, the Microwave Physics Laboratory had many researchers specializing in physics and chemistry, as well as numerous students and graduate students from universities such as Keio University, Tokyo University of Science, Tokyo Institute of Technology, and Chiba Institute of Technology, who were there as trainees. I believe I gained many valuable experiences through various interactions with the researchers and trainees from other universities. As I progressed with my master's research, I became strongly interested in the profession of a "researcher" and decided to proceed to the Doctoral Programs. Eight of my peers advanced to the Doctoral Programs in the Department of Physics. I remember that early in the new semester, Professor Kawamura (who I believe was the Department Head at the time) gave us a rather stern word of encouragement: "A doctorate is like a grain of rice stuck to the sole of your foot—it's annoying if you don't remove it, but just because you've removed it doesn't mean you can eat it (i.e., get a job). Aim for research that is world-class." At the time, the social climate still had lingering effects of the bubble economy, and I personally felt rather optimistic, thinking, "Things will work out somehow."

In the Doctoral Programs, I continued to work on the spectroscopy of highly excited molecules. One day, while conducting an experiment where I combined laser beams and directed them at the target molecules, I discovered the generation of a strong infrared light that was completely different from what I had expected. Initially, I became pessimistic, thinking, "Did I make a mistake in the experiment?" because the expected signal was not observed. However, the strong infrared light continued to be observed with good reproducibility. It turned out that this signal was an emission called ASE (Amplified Spontaneous Emission), and by actively using this emission, we found that we could detect transitions between states of highly excited molecules with high sensitivity. Although ASE was already well-known in fields like laser physics, we were able to demonstrate its usefulness as a research tool for highly excited molecules, and these results led to my doctoral dissertation.

In my third year of the Doctoral Programs, I began to think seriously about my career path after graduation. I remember my supervisor, Professor Uehara, advising me, "There are many different kinds of jobs related to 'research' in the world. Don't be fixated on your field of study from your student days; if there's a job or workplace that needs you, you should tackle it with a positive attitude." Fortunately, I was hired as a researcher at the National Metrology Institute of Japan (now the National Institute of Advanced Industrial Science and Technology), Agency of Industrial Science and Technology, Ministry of International Trade and Industry.

At the National Metrology Institute of Japan, I began to work on research into temperature standards based on the principle of black-body radiation and precision measurement technology for infrared thermal radiation, which are used to calibrate infrared radiation thermometers and thermal imaging devices (thermography). Apart from "measuring light," this research was in a technical field vastly different from my student research, and as a researcher, I was starting from scratch. However, my supervisor at work advised me, "Don't rush, take your time to study thoroughly," so I gradually advanced my research, starting by reading textbooks. Fortunately, my research progressed smoothly, and about five years after joining, I was able to achieve results in my initial task: "the development of national standards for radiation thermometry near room temperature."

Around that time, the "infrared (ear) thermometer" was commercialized as a new type of thermometer, following mercury and electronic ones. Because it could measure body temperature in about one second, it quickly became widespread in hospitals and homes in Japan. On the other hand, since this new thermometer operated on a new principle of measuring infrared thermal radiation from the surface of the skin or eardrum, ensuring the reliability of the measurement data became an issue. Our research group hurried to develop a world-class "standard black-body furnace" to serve as a benchmark for performance testing and scale calibration of the new thermometers. We also collaborated with the government (Ministry of Economy, Trade and Industry; Ministry of Health, Labour and Welfare), thermometer manufacturers, users, and medical experts to participate in creating the Japanese Industrial Standard (JIS) that would serve as the technical standard for performance testing of these new thermometers. Shortly thereafter, SARS (Severe Acute Respiratory Syndrome) became prevalent, mainly in Asian countries, and preventing its spread became an urgent international issue. At that time, at the request of national metrology institutes in countries like Singapore and Taiwan, we provided the standard black-body furnaces and calibration techniques we had developed, which helped in screening febrile patients at airports and seaports. This experience was very meaningful to me as an instance where the standard technology I had developed contributed, even in a small way, to solving a societal problem.

From 2002 to 2003, I had the opportunity to spend a year conducting research abroad at the National Physical Laboratory (NPL), the UK's national standards laboratory. During my stay in the UK, I had many memorable experiences, both professionally and personally. The Optical Radiation Standards group at NPL, where I worked, had two managers: a Science Head, who "leads research activities," and a Management Head, who is "in charge of the management and administration of the research group." Both were excellent researchers, but in terms of research work, the Science Head acted as the accelerator and the Management Head as the brake. In fact, when I stayed late after the official end of the workday (as is common in Japanese workplaces), the Management Head came to me and seriously advised, "If the work assigned to you is beyond your capabilities and you find yourself having to work overtime to finish it, you should consult me. I can negotiate with the Science Head on your behalf." (Of course, from the next day, I made sure to go home without working overtime.) It was a very interesting experience, especially when compared to the research environment in Japan, which can easily become "research-supremacist."

As a researcher specializing in metrology standards, I intend to continue working on advancing national standards, with a focus on radiation thermometry. In standards research, the primary approach is the pursuit of "accuracy." However, I also want to actively engage in developing new measurement methods to solve the measurement needs in industry and science where people say, "I want to measure it, but I can't." Furthermore, in the field of metrology standards, international cooperation and collaboration based on the "Metre Convention" are crucial. For several years now, I have been serving as the chairman of a committee of temperature standards researchers from Asia-Pacific countries. I am facing the difficult challenge of how to enhance the presence of Japan and other Asian nations by leveraging the diversity of values and national circumstances in a world of "standards" that has historically been led by Europe.

In my private life, about three years ago, I resolved to start practicing a wind instrument called the oboe. I secretly hope to be able to play together with my daughter (4 years old), who has started learning the piano. Also, as my metabolic syndrome is progressing, I am determined to finally succeed in the great diet plan that I failed at during my university swimming club days.