CLEO 2016 Shun Fujii

Research

CLEO 2016 Return Report

Shun Fujii, 1st year master's student

About the Conference

This year's CLEO (Conference on Lasers and Electro-Optics) was held in San Jose, USA from June 4 to 10 as usual. The San Jose Convention Center, where the conference was held, was a very clean place with easy access from the station. Later I found out that it was because the local hockey team, the San Jose Sharks, had made it to the playoffs, and the fans were at their peak of excitement thanks to their victory. The local hockey team, the San Jose Sharks, had made it to the playoffs, and the excitement of the fans was at its peak thanks to their victory. This time, I stayed at the Arena Hotel, a seven-minute walk from the station, and walked to the conference venue. I did not end up taking the VTA, which was involved in a commotion at last year's FiO in San Jose, and everything seemed to go without a hitch, but as I was rushing to catch the train home, I was tangled up with a large black man. I tried to ignore him, but he chased after me, shook my hand, and asked me, "Where did you come from? What are you doing here? How long have you been here?" In the end, he let me go with a "good stay" or something like that, and I was able to get away with it. During the conference, I was with Mr. Kato and Mr. Suzuki, and many people from Loncar and Weiner Labs were also there, so I was able to join in the conversation with the seniors who had not seen each other for a long time. I was shocked at first to see such a large number of people as Lipson, Gaeta, Vahala, Kippenberg, Weiner, Chembo, Erkintalo, and so on. Unlike domestic conferences, there were many Microcomb sessions, and it was very good that I could attend every day without getting bored. The food, which I had been worried about, was not a problem.

2. About your own presentation

This time, I made a presentation in Microresonator combs I session. The content of the presentation was mainly on CW-CCW combs, the same as my thesis and thesis presentation. I was the first presenter of the session and it seemed to go relatively smoothly, but I was unexpectedly nervous and skipped some phrases in the beginning of the session. I got used to it and the 12-minute presentation went by quickly, but I did not have time to turn to the audience. I had three questions: What is the power ratio? What is the power ratio? Are the scattering points intentionally attached or does the coupling affect the CW side? Although I understood the intent of the questions, I could not hear them clearly, and I realized how difficult it is to answer questions in English. I also realized the difficulty of the Q&A session in English, and the fact that Chembo, who was in the front row, asked me a question accelerated my impatience. I would like to answer calmly and take revenge at the next opportunity.

3. Contents of the presentation you attended

[STu3Q.5]
"Demonstration of a Soliton Frequency Comb in a High-Q Silica Microresonator" Gr. Vahala
The Vahala group has achieved a soliton stabilization with a repetition rate of 22 GHz using a wedge-silica disk, which has already been published in Optica. The Vahala group has continued to produce impactful research using silica wedge in this field where silicon-nitride has become the mainstream. The Vahala group also presented an ultra-high Q resonator integrating a silica wedge with a nitride waveguide at the post deadline, and also presented a new resonator using a silica wedge with a nitride waveguide at the post deadline.[JTh4B.7]The ability to fix the coupling is a great advantage, and the fact that this was achieved with silica is expected to be a threat. The ability to fix the coupling is a great advantage, and the fact that this has been achieved with silica is expected to pose a threat.

[STu4Q.6]
"Coupling Ideality of Integrated Silicon Nitride.
Microresonators for Nonlinear Photonics" Gr. Kippenberg
A study on coupling of silicon nitride ring resonators. The design of a pulley coupler along the ring makes it easier to obtain phase matching conditions. Specifically, coupling to higher-order modes, which has existed in the past, can be reduced, and the Q value at critical coupling can be improved. This is a point of view that has not been considered before, and its effect was demonstrated in experiments, but I felt that it is not clear whether this will actually become the mainstream. Since phase matching is an extremely important factor in nonlinear phenomena, there may be some value in gaining an understanding of these factors. Especially in the case of SiN resonators, where coupling is determined at the design stage, this kind of knowledge is a research that could become a common understanding in the entire field.

[STu1H.4]
"Modelocked Mid-Infrared Frequency Combs in a Silicon Microresonator" Gr. Gaeta
First-demonstration of mode-locked carcom generation in the mid-infrared region (2.4-3.2 μm) using a Silica microring resonator with a PIN structure, where the PIN-junction is used to control the free-carrier generated by 3PA (3-photon absorption). The PIN-junction is used to control the free-carrier generated by 3PA (3-photon absorption). The soliton step was confirmed by detuning the laser, and it was confirmed that the laser is mode-locked in the mid-infrared band. Mode-locking is also achieved by changing the applied voltage of the reverse bias, which can effectively change the detuning. In the post deadline, the same presenter presented "Dual comb of mid-infrared band" using the above silicon microresonator. The mid-infrared band is convenient for chemical and bioanalytical spectroscopy, including atmospheric analysis, so it is inevitable to move toward dual comb spectroscopy. There were many other presentations on dual comb spectroscopy at this year's CLEO, indicating that it is attracting a lot of attention.

[SW1E.4].
"Generation of an optical frequency comb in the green with silicon nitride microresonators" Gr. Bowers
J. Bowers Gr. at UCSB reported the generation of combs in visible light (green) via 3rd harmonic generation & 3rd sum frequency generation in a SiN resonator. Bowers' gr. seems to focus on silicon photonics, but there is a possibility that he will enter microcomb in the future since Kippenberg is included in his joint name. The presentation was a simple one, in which the harmonics of the comb expanded in the IR region were observed in the visible light band. I had wondered why there had been no study on third harmonic generation in the 780 nm band, while there had been a report on visible comb using SiN resonators via second harmonic generation by Lipson Gr. The reason was not clear.
[SF2O.4]
"On-Chip UV Dispersive Wave Generation" Gr. Vahala
The main feature of the Silica waveguide is that it uses SCG (supercontinuum generation) instead of THG (THG-like harmonic generation). The main feature of the dispersive wave is that it does not use harmonic waves like THGs, but rather SCG (supercontinuum generation). Vahala's group has demonstrated in a waveguide, so it may be only a matter of time before we see it in a resonator. Vahala Gr. can make structures with controlled dispersion, so it is clear that they have many ideas using Silica as a platform.

Shun Fujii
Shun Fujii Presentation