FiO/OSA 2013 Ryodai Fushimi


FIO2013@ORLANDO, FLORIDA Conference Participation Report

Ryota Fushimi, 1st year master's student, Tanabe Laboratory, Graduate School of Science and Engineering

October 15, 2013

A significant proportion of the invited lectures were of overwhelmingly high quality compared to the regular lectures.
Below I will focus on the research that I am particularly interested in.

(Conference plenary lecture)
John E. Bowers, "Silicon photonic integrated circuits and lasers"

He is a leading researcher on Si optical circuits. In his lecture, he explained the current status and background of optical circuits, and then described each element that forms a circuit. Among them, the coupling of SiN waveguides with Si waveguides by nanotapering is one of the most relevant to his research.
In the IME chip, a silica layer is sandwiched between the Si and SiN layers, so it cannot be done in the same way and requires a grating coupler, but if the two layers are adjacent, they can be combined by nanotapering.
Nanotapers are used in spot-size converters and other devices, but there has been little research on their design. We believe that more detailed research on each element is interesting for the development of the field of optical circuits, and we feel that the nanotaper is a good place to start.

Jared F. Bauters,, "Integration of Ultra-Low-Loss Silica Waveguides with Silicon Photonics", IEEE Photonics Conference 2012, September 27, (2012)
Listening to the session on optical circuits, it is clear that the direction of research is shifting from the pursuit of top data to the construction of practical systems. With the move toward industrialization (first of all, optical interconnects), we do not know whether to make maximum use of IMEs and go fabless, or to emphasize speed and accumulate know-how on our own, but we believe that only through experimentation can our research be recognized worldwide.

Jonathan C. Knight, "The Good Bits and Pieces of Microstructured Fibers"

Hollow fibers are hollow structured fibers. Hollow fibers are hollow structured fibers. The characteristic feature of hollow fibers is that they can guide mid-infrared light, which would not be transmitted, or rather absorbed, by ordinary optical fibers. It can even propagate CO2 laser light with a wavelength of 10.6 μm. This is safer than using mirrors or other means to pass through space. Although it is dangerous if the fiber is damaged, this research has various possible industrial applications.

Fei Yu,, "Low loss silica hollow core fibers for 3-4 μm spectral region," Opt. Express 20, 11153-11158 (2012)
General Introduction to Photonic Crystals Session
Nanobeam resonators were widely discussed in the sessions on photonic crystals. The main purpose was for sensor applications, but the ease of design guideline of simply changing the radius linearly may have contributed to the popularity of this trend. Some slot resonators were also introduced.

(FW4E.2) J. Burr, "Giant Slow Wave Resonances in Coupled Periodic Silicon Optical Waveguides"

(FW4E.5) S. Makino,, "Structural Dependence of Nonlinear Characteristics in Coupled Resonator Optical Waveguides Based on Slotted Nanobeam Cavities".

The appeal of this resonator lies in its overwhelmingly small mode volume: the effective mode volume of the L3 resonator is about 0.75, while that of the slot resonator is as small as 0.1. Miller also said that a moderate Q & very small V resonator is necessary to make an optical device comparable to a quantum dot in electronic devices. In my opinion, this is not a realistic device. In my opinion, the structure with small mode volume, such as a slot resonator with moderate Q, rather than a PhC resonator with higher Q, will be the center of the future to make a realistic device. Although plasmon has a small mode volume, it is not easy to control the resonance frequency, so the realistic solution may be a PhC resonator.