PECS XII Tomohiro Tetsumoto

Research

PECS XII Return Report

Tomohiro Tetsumoto

Dates: July 17 - 21, 2016
Location: University of York, York, UK

1. Outline of the Conference

 From July 17 to 21, I attended PECS XII held at the University of York in England (Fig. 1). As the name "Photonic and Electromagnetic Crystal Structures" suggests, this conference is held every two years in a different location. The next conference will be hosted by M. Loncar and will be held near Harvard University in Boston. It was a very high-level conference with top-notch researchers from all over the world (almost everyone I could think of who is a photonic crystal researcher was there). https://www.york.ac.uk/physics/pecs-xii/technicalprogram/fullprogram/ The number of participants was very high. (There were also some great names such as E. Yablonovitch, J. Pendry, and F. Cappasso (via skype)). The only disappointment was the cancellation of Painter's presentation. Instead, the sponsor, Nat. Photonics, gave a talk titled "Ten years of Nat. Photonics," in which the opening slide showed Dr. Tanabe's presentation of the world's first 106The paper on photonic crystal resonators that exceeded the

One of the unique features of this year's conference was the discussion session. The topics of discussion were as follows: "Why does the π/2 shift occur when light enters the resonator? Why does the π/2 shift occur when light is input to the resonator? The moderator, T. Krauss, was in charge well, and the discussions were lively, though sometimes digressing. What I felt there was that people from all over the world had the same awareness of the issues. Some of the topics mentioned above have been raised in Tanabe Lab. It was interesting to hear other people's opinions about such common problems. I thought it was a good trial.

I was also impressed by the strong research capabilities of Japanese research groups in the field of photonic crystals. In contrast to the WGM resonator field, where there are almost no Japanese researchers, in the photonic crystal field, there are many leading research groups including Noda Lab, which is pioneering various applications in the photonic crystal field based on ultra-high Q resonator fabrication technology, Baba Lab for slow light and ultra-high sensitivity biosensing, NTT's Notomi Lab for optical signal processing, and the Arakawa-Iwamoto Lab for quantum optics. The Noda Lab. is pioneering various applications in the field of crystallography, Baba Lab. On the other hand, other groups seem to have followed the Japanese group and steered their research toward other fields such as plasmons and metamaterials, rather than competing with them. This is a wise decision in the field of photonic crystals, where applications have been slow to emerge. The cost of photonic crystals is so low that it is difficult to know whether they can be used or not, even though high technology is required to fabricate them. I have the impression that many new applications of photonic crystals have emerged in recent years, but otherwise, the Japanese group may have been left behind in terms of applications. I felt the importance of continuous participation in academic conferences and consideration of research directions to avoid isolation in research fields and lagging behind when new fields emerge. Tanabe Lab. at Keio University is hardly known in the industry, so we felt the need to disseminate our research with impact.

Fig. 1 (a) Accommodations at York University. (b) A full view of one block of accommodations. (b) A full view of one block of accommodations, with the building in the back of the photo as one set, and many of these (there were A to K on the map).
Fig. 1 (a) Accommodations at York University. (b) A full view of one block of accommodations. (b) A full view of one block of accommodations, with the building in the back of the photo as one set, and many of these (there were A to K on the map).

2. Regarding your own presentation

This time, I gave a poster presentation on the isolated mode of coupling resonator formation using fiber-coupled photonic crystal resonators. The presentation was given to less than 10 people, many of whom had various backgrounds in the field of photonic crystals, and many asked questions about basic matters such as the principle of resonator formation. On the other hand, those who are close to my specialty asked me about my future direction. Although I said that I would conduct experiments on optical signal processing, the only functional advantage over existing devices is very low insertion loss. In order to take advantage of this advantage, we would like to consider coupling with devices of other platforms such as toroids and applications in the field of quantum optics as a promising direction.

3. Topic Introduction

T. Cunningham, et al. , "Photonic Crystal Enhanced Microscopy for Cell Membrane Imaging and Digital Resolution Biomolecular Sensing".

Cellular imaging using coevolutionary wavelength change of standing waves in grating structures. Cellular changes such as tumor invasion, stem cell differentiation, cell death, and cancer metastasis occur when cells are attached to thin films (or cultured), and a method that satisfies the requirements of label-free, quantifiable, high spatial resolution, and long-term availability is needed to observe these changes in detail. In this study, we showed that cell imaging that satisfies the above requirements is possible by attaching cells to a grating made of polymer and ITO, based on the local resonance wavelength change at the cell attachment site. The Tanabe Lab was interested in the cell cycle at one time, but at that time, there were promising tools for this purpose in the world. I was reminded of the importance of broadening one's perspective by investigating related research and attending academic conferences.

A. Schulz, et al. , "Photonic Crystal Waveguides in a Kagome Lattice".

W1-type waveguides, in which one line of the periodic structure of a triangular lattice is filled in, are mainly used for slow light generation using photonic crystal waveguides. However, W1 waveguides must be designed to operate at the band edge, where dispersion and loss are high, and even when optimized, the group refractive index is limited to about 150. This study shows that slow light with a group refractive index exceeding 150 can be realized outside of the band edge by using a photonic crystal waveguide with a Kagome lattice structure (numerical analysis shows a group refractive index of over 10,000). It seems that defects above and below the waveguide act like coupling resonators to realize slow light. The group refractive index was measured experimentally, and the performance was comparable to that of existing devices. I had the impression that Kagome lattices are often used in photonic crystal fiber applications, but I had never thought of using them as waveguides. From what I have heard, there are many advantages to slow light, and I expect that there will be a report showing high performance in the near future.