CHU, WHWHCHUMING-FENG SHIH2018-09-102018-09-10200900304018http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000266131400023&KeyUID=WOS:000266131400023http://scholars.lib.ntu.edu.tw/handle/123456789/348852https://www.scopus.com/inward/record.uri?eid=2-s2.0-65249085596&doi=10.1016%2fj.optcom.2009.02.067&partnerID=40&md5=ac2505731c5c6522627898df637f3d82We find theoretically that the optical modulation instability can spontaneously happen in the noninstantaneous defocusing medium when there is a coherent feedback. It requires both above-threshold gain and phase matching for the instability to happen, very similar to the oscillation condition of a laser. The theoretical result is in good agreement with our experimental observation. © 2009 Elsevier B.V. All rights reserved.Coherent feedback; Modulation instability; Noninstantaneous; Self-defocusingCoherent feedback; Defocusing; Experimental observations; Modulation instability; Noninstantaneous; Optical modulations; Self-defocusing; Theoretical results; Threshold gains; Feedback; Modulation; Stabilityjournal article10.1016/j.optcom.2009.02.0672-s2.0-65249085596WOS:000266131400023