?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Sub-wavelength+near+field+imaging+techniques+at+terahertz+frequencies&rft.creator=Giordano%2C+MC&rft.creator=Viti%2C+L&rft.creator=Mitrofanov%2C+O&rft.creator=Scamarcio%2C+G&rft.creator=Mastel%2C+S&rft.creator=Hillenbrand%2C+R&rft.creator=Ercolani%2C+D&rft.creator=Sorba%2C+L&rft.creator=Vitiello%2C+MS&rft.description=Near-field+imaging+techniques+at+terahertz+(THz)+frequencies+are+severely+restricted+by+diffraction.+To+date%2C+different+detection+schemes+have+been+developed%2C+based+either+on+sub-wavelength+metallic+apertures+or+on+sharp+metallic+tips.+However+high-resolution+THz+imaging%2C+so+far%2C+has+been+relying+predominantly+on+detection+techniques+that+require+either+an+ultrafast+laser+or+a+cryogenically-cooled+THz+detector%2C+at+the+expenses+of+a+lack+of+sensitivity+when+high+resolution+levels+are+needed.+Here%2C+we+demonstrate+two+novel+near-field+THz+imaging+techniques+able+to+combine+strongly+sub-wavelength+spatial+resolution+with+highly+sensitive+amplitude+and+phase+detection+capability.+The+first+technique+exploits+an+interferometric+optical+setup+based+on+a+THz+quantum+cascade+laser+(QCL)+and+on+a+near-field+probe+nanodetector%2C+operating+at+room+temperature.+By+performing+phase-sensitive+imaging+of+THz+intensity+patterns+we+demonstrate+the+potential+of+our+novel+architecture+for+coherent+imaging+with+sub-wavelength+spatial+resolution+improved+up+to+17+%CE%BCm.+The+second+technique+is+a+detector-less+s-SNOM+system%2C+exploiting+a+THz+QCL+as+source+and+detector+simultaneously.+This+approach+enables+amplitude-+and+phase-sensitive+imaging+by+self-mixing+interferometry+with+spatial+resolution+of+60-70+nm.&rft.subject=Terahertz+radiation%2C+Near+field%2C+Near+field+optics%2C+Quantum+cascade+lasers%2C+Signal+detection%2C+Sensors%2C+Spatial+resolution&rft.publisher=SPIE&rft.contributor=Razeghi%2C+M&rft.contributor=Brown%2C+GJ&rft.contributor=Lewis%2C+JS&rft.contributor=Leo%2C+G&rft.date=2018-01-26&rft.type=Proceedings+paper&rft.publisher=Conference+on+Quantum+Sensing+and+Nano+Electronics+and+Photonics+XV&rft.language=eng&rft.source=+++++In%3A+Razeghi%2C+M+and+Brown%2C+GJ+and+Lewis%2C+JS+and+Leo%2C+G%2C+(eds.)+Proceedings+of+the+Quantum+Sensing+and+Nano+Electronics+and+Photonics+XV.++++SPIE%3A+Bellingham+(WA)%2C+USA.+(2018)+++++&rft.format=text&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F10060151%2F1%2FMitrofanov_Sub-wavelength%2520near%2520field%2520imaging%2520techniques%2520at%2520terahertz%2520frequencies_AAM.pdf&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F10060151%2F&rft.rights=open