Abstract
The whispering gallery is located in the dome of St Paul's Cathedral in London. If two people stand on opposite sides of the gallery and one of them whispers into the wall, the other can hear his or her words. The reason for this strange effect is that sound bounces along the wall as a surface wave with low loss, and so can be heard far away. This phenomenon, known as whispering gallery mode (WGM), was discovered by Lord Rayleigh in the 18th century. It has found new notoriety in the past few decades in the optics domain: ultra-high Q-factor, i.e., ultralow loss, optical resonators, based on WGMs have been demonstrated, opening up exciting new research frontiers in low-power nonlinear optics, optomechanics, optical processing, and sensing (1, 2). In PNAS, Wang et al. manage to demonstrate what eluded researchers for many years: a semiconductor microlaser emitting a unidirectional low-divergence beam based on optical WGMs (3).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
