SPIE Photonics West 2016 Tomohiro Tetsumoto

2016-01-18 2022-09-24 miyahara

Research

Report on participation in SPIE PHOTONICS WEST 2016

Tomohiro Tetsumoto, 1st year doctoral student, Tanabe Laboratory

1. Outline of the Conference

I attended SPIE Photonics West 2016 held in San Francisco, U.S.A. (Fig.1 (a)(b)) SPIE is an American optical society along with OSA. The size of the conference was quite large, with three categories (LASE, OPTO, and BIOS) and three venues. The quality of the presentations varied widely, but one professor said that CLEO was full of research that had been published in papers, while PW sometimes contained interesting and novel research that would have been dismissed at other conferences. Another point worth mentioning is the large scale of the corporate exhibition (Fig. 1 (c)). Many companies exhibited, though not as many as at CLEO Europe, which I attended last year. This may be one of the reasons why I had an impression that there were many presentations from companies in the sessions I attended (this may be due to the fact that I visited sessions on silicon photonics, MOEMS, etc.).

2. Regarding your own presentation

This time, I gave an oral presentation on the formation of coupled resonators using fiber-coupled photonic crystal resonators. Although I was in a bit of a hurry to improve the data and revise the manuscript until just before the presentation, I was able to give the presentation calmly. After the presentation, there were two questions: one was how the critical coupling between the fiber and the resonator was realized, and the other was whether EIT could be realized in this system. Although I could understand the intention of both questions, there was a slight delay in my response, so I would like to improve my speaking reflexes. I also had an impression that it was difficult to convey the point that the experiment was conducted with the fibers in constant contact with each other.

3. Topic Introduction

[9759-7] Ultrafast third-harmonic spectroscopy of single nanoantennas fabricated using helium-ion beam lithography

I attended the session on FIB fabrication technology. The background of the research was the need to localize optical modes in a very small volume in order to realize ultrafast optical transistors, and the presentation was about the fabrication of bow-tie type nano antennas and their performance. In this presentation, FIB with He+ ions was introduced. In the presentation, an antenna with an amazing nano gap of 6 nm in gap length was introduced (Fig. 2(a)). The antenna fabricated with He+ ions showed higher nonlinearity (Fig. 2(b)) and better polarization dependence than the antenna fabricated with Ga+ ions (gap = 20 nm). Microscopy GmbH, and Univ. Bielefeld. The relationship is beneficial to both the university and the company, as the developed advanced technology is effectively used for basic research at the university, and the findings are immediately fed back to the company side.

FIB is a simple method in that it does not require lithography and can directly create patterns, enabling highly accurate microfabrication. On the other hand, FIB is not good at large-area pattern fabrication, and has the problems of non-smooth stitching at the pattern joints and long drawing time. Although we usually see beautifully finished structures, it is necessary to take into account the effects of ion scattering and to remove the effects of substrate electrification. In general, I got the impression that this technology is still more for research and development than for industrial use, as it is suitable for metal processing of fine patterns such as plasmon research.

[9759-14] Packaging and micro-structuring for enabling multi-functional fiber-cladding photonics and lab-in-fiber

A presentation from the University of Toronto, Canada. The presentation is about the fabrication of waveguides, liquid channels, and other optical elements in optical fibers by femtosecond laser imaging. Although processing using femtolasers to modify glass is a familiar topic, this is the first time I have heard of a presentation on the integration of various elements as in this case. In the presentation, interesting applications such as shape sensing of fibers (Opt. Express, 21(20), 24076-24086 (2013)) were introduced. I was impressed by the fact that the technology can be used in a variety of ways if it is mastered. In fact, they seem to be actively collaborating with companies, and Oz Optics (a VOA company) is one of the joint authors of the following article.

[9742-34] Integrated nanophotonic devices for optical interconnections

Fig. 4(a) shows the structure of the device, which consists of a waveguide and a side-coupled ring resonator, and eight side-coupled waveguides with the same coupling coefficient. There is a ring resonator side-coupled to a waveguide, and inside the ring resonator are eight side-coupled waveguides with the same coupling coefficient. The light entering the eight waveguides from the ring resonator is coupled at different positions and has different phase relationships, so the light emitted into space becomes their super modes and has angular orbital momentum. Since light with angular orbital momentum (optical orbital angular momentum: OAM) has numerous eigenstates, it can be used to increase the information capacity of data communications. In the presentation, it was shown that the shape of the OAM beam emitted from each mode of the ring resonator is different (Fig. 4(b)) and that the shape of the OAM beam was experimentally controlled by using a phase shifter (Scientific Reports 5, 10958 (2015).) The paper uses IMEs for fabrication (the paper does not seem to mention the use of IMEs for this element, so it may be for other devices).