Observation of an exceptional point in a chaotic optical microcavity

• Published in: Physical review letters Vol. 103; no. 13; p. 134101
• Main Authors: Lee, Sang-Bum, Yang, Juhee, Moon, Songky, Lee, Soo-Young, Shim, Jeong-Bo, Kim, Sang Wook, Lee, Jai-Hyung, An, Kyungwon
• Format: Journal Article
• Language: English
• Published: United States 25-09-2009
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.103.134101

We present spectroscopic observation of an exceptional point or the transition point between mode crossing and avoided mode crossing of neighboring quasieigenmodes in a chaotic optical microcavity of a large size parameter. The transition to the avoided mode crossing was impeded until the degree of deformation exceeded a threshold deformation owing to the system's openness also enhanced by the shape deformation. As a result, a singular topology was observed around the exceptional point on the eigenfrequency surfaces, resulting in fundamental inconsistency in mode labeling.