SPIE Photonics West 2018 Den Kumagai

2018-01-17 2022-09-24 miyahara

Research

SPIE Photonics West 2018 Participation Report

PD Den Kumagai

Outline

We attended SPIE Photonics West 2018 held in San Francisco from January 27-February 1, 2018. San Francisco was warmer than Japan, especially on the warmest days, with a maximum temperature of 18°C. The weather was wonderful. SPIE Photonics West is the largest conference in the field of photonics, attracting about 30,000 participants. There were large sessions on lasers, optics, and bio, and there were (a few) many presenters, especially in the bio-related fields. Since many prominent researchers are invited as Invited speakers, it is a good conference to make connections and have face to face discussions with colleagues. I would like to report on my presentation and other interesting talks at the conference.

Announcement

The presentation entitled "Saturable absorption by carbon nanotubes on silica microtoroids for stable mode locking" was given. The details of the presentation were about the preparation of CNTs by CVD method and the evaluation of saturable absorption properties by pump-probe experiments. The audience was not so large, about 30 people, probably because of the late presentation time and the time for the poster session and reception in the evening. Many of the questions were simple, such as "What was the initial Q value and what happened to it? Since solitons are realized only by so-called dispersive design, it is unlikely that much attention will be paid unless mode synchronization using saturable absorbers is demonstrated.

3. lectures

●MG Suh (Caltech) - Microcomb LIDAR using counter-propagating solitons
Although Vahala's talk was on the program, Suh of the Vahala group gave a presentation on dual-comb spectroscopy and LIDAR applications based on micro optical resonators instead. First of all, gas sensing using dual-comb solitons was explained. Absorption spectra of H13CN gas measured with a dual comb in the 1550 nm band were found to be comparable to those obtained with conventional high-performance scanning lasers. The application to high-resolution sensing at the chip scale is expected (see http://science.sciencemag.org/content/354/6312/600 for details).
Next, LIDAR applications were explained. He showed the distance measurement of the dual comb lidar by collimating the light from the end of the fiber. Although it is lab-scale, it can accurately measure up to 26 meters, and theoretically can measure up to 26 kilometers (which is amazing, apparently) with high accuracy. This also shows that highly accurate chip-scale measurements are becoming more practical (for details, please refer to the following page).https://arxiv.org/abs/1705.06697(See Figure 1.). In addition, they introduced that three solitons (pump, Raman, and Stokes) were obtained from the same device, although they have not been published yet. Personally, I feel that we are far from the total chip base in reality, but the presentation showed the high level of technology of the Vahala group.

Unknown (EPFL) - Dissipative Kerr solitons in optical microresonators
Although Kippenberg's talk was on the program, a group member gave a presentation on dissipative cur solitons (DKS) instead. He talked about the fundamentals of DKS, such as the need to minimize noise (e.g., thermal) and the need for fine tuning of detuning in order to bring the soliton to a stable soliton state. As for the latest research, he presented the application to high-capacity optical communications (Journal Club article). https://www.nature.com/articles/nature22387The presentation covered applications such as high-speed profiling of the shape of bullets fired from a gun, astro-com, and LIDAR-like applications.
In addition, as a memo note, it is important to accurately measure the roughness of fluoride resonators and surfaces because the roughness has a significant effect on the Q-value. Chembo et al. used white interference light to measure surface roughness with high accuracy. Also related to dark solitons, Miro Erkintalo (New Zealand) and his group reported that it is feasible for large resonators such as fiber systems.
(in Japanese history) https://link.springer.com/article/10.1140/epjd/e2017-80133-7).