Academic lecture of Institute of Photonics Technology (No. 113)

Topic: Towards a perfect hollow-core fiber
Date: June 14, 2018
Time: 10:00 a.m.
Venue: Room 405, Tsang Hin-chi Science Hall
Speaker:  Associate researchfellow Ying-ying WANG
Host: Researchfellow Long JIN

Abstract: The invention of optical fiber in the 20th century has not only revolutionized the way people communicate but also brought about significant changes in optical sensing, laser and many emerging research fields. However, in the 21st century, with the dramatic increase of the global internet traffic, there's a general fear of a possible capacity crunch in the near future, which is grounded in the intrinsic material imperfection of silica optical fiber, i.e. Rayleigh scattering loss (RSL), chromatic dispersion, and Kerr nonlinearity. In other research fields, the pursuit for higher laser power, higher sensitivity of specific physical quantities and many new requirements in biophotonics, quantum optics, etc. also calls for a revolution in the optical fiber itself. Hollow-core fiber (HCF), allowing light to travel in a quasi-vacuum optical environment with unique merits of low nonlinearity, low dispersion, low latency and potentially low loss, points out a promising avenue for solving the upcoming key problems in these areas. The investigation on the ultimate limit of HCF has become a hot research topic with intense attention worldwide. In this talk, we review our recent progress towards a “perfect hollow core fiber, including our unique understanding of the guidance mechanism of anti-resonant type HCF, the novel design and fabrication of several HCF structures, and several applications in lasers, sensing and potentially optical communications. In particular, our newly fabricated conjoined-tube HCF exhibits an ultralow loss of 2 dB/km at 1512 nm and a < 16 dB/km bandwidth of 335 nm, beating all of the existing types of HCF. It could be a potential rival to the silica optical fiber in the future for solving the communication capacity crunch issue.