I-laser eshayayo enezinga eliphezulu lokuphindaphinda

I-laser eshayayo enezinga eliphezulu lokuphindaphinda

Ezweni elincane kakhulu lokuxhumana phakathi kokukhanya nezinto, ama-pulse e-repetition rate pulses (ama-UHRP) asebenza njengababusi besikhathi abanembile - ajikeleza izikhathi ezingaphezu kwezigidigidi ngomzuzwana (1GHz), abambe izigxivizo zeminwe zamaseli omdlavuza ekucabangeni kwe-spectral, ephethe inani elikhulu ledatha ekuxhumaneni kwe-optical fiber, futhi alinganise ama-wavelength coordinates ezinkanyezi kuma-telescope. Ikakhulukazi ekugxumeni kobukhulu bokuthola be-lidar, ama-terahertz ultra-high repetition rate pulsed lasers (100-300 GHz) aba amathuluzi anamandla okungena kungqimba lokuphazamiseka, eshintsha imingcele yokuqonda okunezinhlangothi ezintathu ngamandla okuphatha i-spatiotemporal ezingeni le-photon. Njengamanje, ukusebenzisa izakhiwo ezincane zokwenziwa, njengezikhala ezincane ezidinga ukunemba kokucubungula kwe-nanoscale ukuze kukhiqizwe ukuxubana kwamagagasi amane (i-FWM), kungenye yezindlela eziyinhloko zokuthola ama-pulse e-optical rate repetition rate aphezulu kakhulu. Ososayensi bagxile ekuxazululeni izinkinga zobunjiniyela ekucutshungulweni kwezakhiwo ezinhle kakhulu, inkinga yokulungisa imvamisa ngesikhathi sokuqala kwe-pulse, kanye nenkinga yokusebenza kahle kokuguqulwa ngemva kokukhiqizwa kwe-pulse. Enye indlela ukusebenzisa imicu engeyona eye-linear kakhulu nokusebenzisa umphumela wokungazinzi kokuguquguquka noma umphumela we-FWM ngaphakathi kwe-laser cavity ukuze kushukunyiswe ama-UHRP. Kuze kube manje, sisadinga "i-time shaper" enekhono kakhulu.

Inqubo yokukhiqiza i-UHRP ngokufaka ama-pulse e-ultrafast ukuze kuvuselelwe umphumela we-FWM ohlakazayo ichazwa ngokuthi “ukuvutha kwe-ultrafast”. Ngokungafani nohlelo lwe-microring cavity olushiwo ngenhla oludinga ukupompa okuqhubekayo, ukulungiswa okunembile kokukhipha ukuze kulawulwe ukukhiqizwa kwe-pulse, kanye nokusetshenziswa kwemidiya engeyona eye-linear kakhulu ukuze kwehliswe umkhawulo we-FWM, lokhu “kuvutha” kuncike ezicini zamandla aphezulu ama-pulse e-ultrafast ukuze kuvuselelwe i-FWM ngqo, futhi ngemva “kokucima”, kufinyelele i-UHRP ezisekelayo.

Isithombe 1 sibonisa indlela eyinhloko yokufeza ukuzihlela kwe-pulse ngokusekelwe ekuvuseleleni kwe-pulse yembewu okusheshayo kwemigodi yendandatho ye-fiber ehlakazayo. I-pulse yembewu emfushane efakwe ngaphandle (isikhathi T0, imvamisa yokuphindaphinda F) isebenza "njengomthombo wokushisa" ukuvusa insimu ye-pulse enamandla aphezulu ngaphakathi kwe-cavity yokuhlakazeka. Imojula yokuthola yangaphakathi kweseli isebenza ngokubambisana ne-spectral shaper ukuguqula amandla e-pulse yembewu abe yimpendulo ye-spectral efana nekamu ngokulawulwa kwamalunga endaweni ye-frequency yesikhathi. Le nqubo idlula imikhawulo yokupompa okuqhubekayo kwendabuko: i-pulse yembewu iyavala lapho ifika emkhawulweni we-FWM wokuhlakazeka, futhi i-cavity yokuhlakazeka igcina isimo sokuzihlela se-pulse ngebhalansi enamandla ye-gain and loss, kanye nemvamisa yokuphindaphinda kwe-pulse engu-Fs (ehambelana ne-intrinsic frequency FF kanye ne-period T ye-cavity).

Lolu cwaningo lwenze nokuqinisekiswa kwethiyori. Ngokusekelwe kumapharamitha asetshenziswe ekusethweni kokuhlola kanye ne-1psi-laser ye-pulse esheshayonjengensimu yokuqala, ukulingisa ngezinombolo kwenziwa enqubweni yokuziphendukela kwemvelo yesizinda sesikhathi se-pulse kanye nemvamisa ngaphakathi kwe-laser cavity. Kwatholakala ukuthi i-pulse idlule ezigabeni ezintathu: ukuhlukana kwe-pulse, i-pulse oscillation ngezikhathi ezithile, kanye nokusatshalaliswa kwe-pulse okufanayo kuyo yonke i-laser cavity. Lo mphumela wezinombolo uphinde uqinisekise ngokugcwele izici zokuzihlela ze-i-laser ye-pulse.

Ngokuqala umphumela wokuxubana kwamagagasi amane ngaphakathi kwesikhala sendandatho yefayibha echithekayo ngokusebenzisa ukusha kwe-pulse yembewu okusheshayo, ukukhiqizwa kokuzihlela kanye nokugcinwa kwama-pulse e-frequency aphindaphindayo angaphansi kwe-THZ (ukukhishwa okuzinzile kwamandla angu-0.5W ngemva kokucima kwembewu) kufezwe ngempumelelo, okuhlinzeka ngohlobo olusha lomthombo wokukhanya wensimu ye-lidar: Ukuphindaphinda kwayo kwezinga le-sub-THZ kungathuthukisa isinqumo sefu lephuzu ezingeni le-millimeter. Isici sokuzigcina se-pulse sinciphisa kakhulu ukusetshenziswa kwamandla esistimu. Isakhiwo se-fiber yonke siqinisekisa ukusebenza okuzinzile okuphezulu ebhendini lokuphepha kwamehlo elingu-1.5 μm. Uma sibheka esikhathini esizayo, lobu buchwepheshe kulindeleke ukuthi buqhube ukuvela kwe-lidar efakwe emotweni iye ekuncipheni (ngokusekelwe kuzihlungi ezincane ze-MZI) kanye nokutholwa kwebanga elide (ukwandiswa kwamandla kuya ku-> 1W), futhi kuhambisane nezidingo zokuqonda zezindawo eziyinkimbinkimbi ngokusebenzisa ukusha kwe-multi-wavelength edidiyelwe kanye nokulawulwa okuhlakaniphile.