Enhanced ZnO based UV photonics and related applications
2015.07.23 16:31
| seminar Date | |
|---|---|
| Date & Time | 2015/07/23, 1:30PM |
| Venue | E4, B401 |
| Speaker | Prof. Gilles Lérondel (Univ. of Technology of Troyes) |
Enhanced ZnO based UV photonics and related applications
2015/07/23, Thu, 1:30PM, E4 B401
Prof. Gilles Lérondel, Univ. of Technology of Troyes
Widedirectbandgapaswellaslargeexcitonbindingenergyandrelativelyhighrefractiveindex,areonlyafewoftheintrinsicpropertiesmakingzincoxideextremelyrelevantforUVphotonicsandrelatedapplications.DespitenumerousstudiesonZnOsincethefirstobservationatroomtemperatureofUVstimulatedemission[1]inepitaxialthinfilm,resonantlight-matterinteractionviaperiodicpatterningattheemissiondiffractionlimit(∽100nm),stillremainamajorissuewhateverthemateriali.e.thinfilmsornanowires.WewillreviewsomeofourlatestresultsobtainedtowardsthisgoalonwaveguidinghighqualityepitaxialthinfilmsgrownonsapphireeitherbyPLDorOCVD.Wewillstartwiththeobservationofrandomlasing[1]andhighgainandlowloss[2]insuchathinfilm.WewillthenshowhowhighgainandlowlosscanbeusedforanewkindofefficientopticalenergytransferbetweenZnOandultrathinluminescentfilms[3].Wewillthenfinallydiscussaboutthepatterningissueofsuchhighqualityepitaxialthinfilmusingtop-downapproach.Whileresonantpatterningisdesirableforafullcontrolofthespontaneousemissionrate,micronscalestructuringcombinedwithin-planewaveguidingcanalsoleadtoenhancedstimulatedemissioni.e.lowerthresholdandhigherinternalquantumefficiency[4].Suchwaveguidingenhancedpropertiesareespeciallyrelevantforsolidstatelightingandsensingapplications.
Contact: Prof. Yong-Hoon Cho (yonghcho@kaist.ac.kr, 2549)
