CLEOPR 2022 Ryo Sugano


CLEO-PR 2022 Participation Report

31st July -5th August 2022, Sapporo Convention Center

Ryo Kanno, 2nd year master's student

About CLEO-PR2022

The 2022 conference was held as a hybrid conference, and there were many participants from India and other West Asian countries, as well as from the Pacific Rim, both offline and online. The conference was held in Sapporo, Japan, and there were many Japanese participants, and explanations were given in Japanese at the poster session, etc., making the conference easy to understand for an international conference.
One drawback of CLEO is that there is no on-demand service. Therefore, the online advantages of CLEO were not so apparent, even though it was a hybrid event. However, there were food and beverages available at every corner of the venue, and there was also space near the entrance for sponsors, some of whom are also members of our laboratory.

2. Presentation by the presenter

Title: Low-cost photonic crystal spectrometer using up-conversion
Presenter: Ryo Sugano
Affiliation: Keio University
Presentation No.: CFP8I-01 (Fri, Aug 5th)

A spectrometer that converts telecommunication wavelength bands to visible light using upconversion was presented.
It uses a random photonic crystal waveguide with a chirped structure in which the waveguide width is gradually narrowed, and the position of the localized light leakage changes according to the input wavelength. This localized light is very wavelength-dependent, making it possible to perform spectroscopy, and by wavelength-converting the leaked light, it is possible to take images using an inexpensive CMOS camera instead of an expensive IR camera. The conventional method used in our laboratory has the problem that it takes a long time to obtain spectral results. To solve this problem, deep learning was used to shorten the time to less than subseconds.
I was able to hear all the questions, but I regret that my answers were compromised by my inability to translate them into English.

3. presentations attended

Title: Strong Phase-Noise Suppression of a Kerr Comb via synchronization to an Optical
Parametric Oscillator
Presenter: Jae K. Jang
Affiliation: Columbia University
Presentation No.: CTuP6A-02 (Tue, Aug 2nd)

This is a study of mode-locked Kerr solitons on Lipson & Gaeta SiN synchronized with a third-order parametric oscillator, which serves as the master oscillator and transfers its excellent phase noise characteristics to the Kerr comb, dramatically improving phase noise. The parametric oscillator is the master oscillator, and its excellent phase noise characteristics are transferred to the Kerr comb, resulting in a dramatic improvement in phase noise.
Each resonator has a heater for thermal control, and the thickness of the SiN film is 730 nm.

Title: Integrated Silicon photodetectors in Silicon Nitride-on-SOI platform
Presenter: Shankar Kumar Selvaraja
Affiliation: Indian Institute of Science
Presentation No. CThP8F-01 (Thu, Aug 4th)

The presentation showed that the SiN-Si multilayer junction was operated in the 850 nm band, with the goal of using it for detector integration and short-distance transmission. The junction loss is 2.3 dB/coupler, which is a little higher than other multi-layer studies, but the fact that a series of experiments have been conducted is a threat.
The thickness of the SiN film is 0.4 µm, and since some previous papers have used a ring detector on the SiN side, it does not seem that the primary goal is to set up a comb, but it seems that WDM is also being considered.

Title: Enhancement of Fiber-to-Waveguide Coupling Efficiency of Silicon Nitride Integrated Optical Circuits
Presenter: Xiaotian Zhu
Affiliation: City University of Hong Kong
Presentation No. CTh12D-07 (Thu, Aug 4th)

This is a study of efficient bonding of SMF and SiN. Insertion loss is reduced by adding silica glass with high refractive index. The sample difference is not that large. The multi-layers and three-step process are very large, and the wavelength dependence on the gap seems to be large, so the loss is small in the C-band band, but it may be a problem when the movable band is expanded in the future. The SiN film seems to have a thickness of 1.0 µm, which suggests that the company is aiming to generate combs in the future.