Ukujabula kwama-harmonics esibili ku-spectrum ebanzi

Ukujabula kwama-harmonics esibili ku-spectrum ebanzi

Kusukela ekutholweni kwemiphumela ye-optical ye-second-order nonlinear optical ngawo-1960, sekuvuse isithakazelo esikhulu kubacwaningi, kuze kube manje, ngokusekelwe emiphumeleni yesibili ye-harmonic, kanye nemvamisa, ikhiqize kusukela ku-ultraviolet eyeqisayo kuya ebhendini elikude le-infrared.ama-laser, ithuthukise kakhulu ukuthuthukiswa kwe-laser,opticalukucutshungulwa kolwazi, ukuma kwe-microscopic enesinqumo esiphezulu neminye imikhakha. Ngokusho nonlinearopticskanye nethiyori ye-polarization, umphumela we-optical nonlinear oda olinganayo uhlobene eduze ne-crystal symmetry, futhi i-coefficient engaqondile ayiyona i-zero kuphela kumidiya ye-symmetric ye-inversion engekho emaphakathi. Njengomphumela oyisisekelo we-second-order nonlinear, i-harmonics yesibili ivimbela kakhulu isizukulwane sabo kanye nokusetshenziswa okuphumelelayo ku-quartz fiber ngenxa yefomu le-amorphous kanye ne-symmetry of center inversion. Njengamanje, izindlela ze-polarization (i-polarization ye-optical, i-polarization eshisayo, i-polarization yensimu kagesi) ingabhubhisa ngokwenziwa ukulinganisa kwe-inversion yesikhungo sezinto ezibonakalayo se-fiber optical, futhi ithuthukise ngokuphumelelayo i-second-order nonlinearity ye-fiber optical. Kodwa-ke, le ndlela idinga ubuchwepheshe bokulungiselela obuyinkimbinkimbi futhi obudingayo, futhi ingahlangabezana nezimo zokumadanisa izigaba zamaza ngamaza ahlukene. I-optical fibre resonant ring esekelwe kumodi yodonga lwe-echo ikhawulela isasasa le-spectrum elibanzi lama-harmonics esibili. Ngokuphula i-symmetry yesakhiwo esingaphezulu se-fiber, i-harmonics yesibili engaphezulu ku-fiber yesakhiwo esikhethekile ithuthukiswa ngezinga elithile, kodwa namanje incike ku-pulse yepompo ye-femtosecond enamandla aphezulu kakhulu. Ngakho-ke, ukukhiqizwa kwemiphumela ye-optical ye-second-order nonlinear optical kuzo zonke izakhiwo ze-fiber kanye nokuthuthukiswa kokusebenza kahle kokuguqulwa, ikakhulukazi ukukhiqizwa kwe-harmonics yesibili ye-wide-spectrum kumandla aphansi, ukupompa optical okuqhubekayo, yizinkinga eziyisisekelo ezidinga ukuxazululwa. emkhakheni we-nonlinear fiber optics namadivayisi, futhi anokubaluleka okubalulekile kwesayensi kanye nenani elibanzi lesicelo.

Ithimba labacwaningi e-China lenze isiphakamiso sohlelo lokuhlanganisa isigaba sekristalu se-gallium selenide esine-micro-nano fiber. Ngokusebenzisa i-high-order yesibili engaqondile kanye nokuhleleka okude kwamakristalu e-gallium selenide, i-wide-spectrum ye-second-harmonic excitation kanye nenqubo yokuguqulwa kwama-multi-frequency iyatholakala, okuhlinzeka ngesixazululo esisha sokuthuthukisa izinqubo ze-parametric eziningi i-fiber kanye nokulungiswa kwe-broadband yesibili-harmonicimithombo yokukhanya. Ukuvuswa okuphumelelayo komphumela we-harmonic wesibili kanye nesamba semvamisa esikimini kuncike kakhulu kulezi zimo ezintathu ezibalulekile ezilandelayo: ibanga elide lokusebenzisana kokukhanya phakathi kwe-gallium selenide kanyei-micro-nano fiber, i-oda eliphezulu lesibili elingelona i-linearity kanye ne-oda lebanga elide lekristalu ye-gallium selenide enezingqimba, kanye nezimo zokufanisa isigaba semodi eyisisekelo yokuphindaphinda nokuphindaphinda kabili ziyaneliswa.

Esivivinyweni, i-micro-nano fiber elungiselelwe isistimu yokuthwebula i-flame scanning inendawo yekhoni efanayo ngokulandelana kwe-millimeter, ehlinzeka ngobude besenzo obungaqondile bokukhanya kwepompo kanye negagasi lesibili le-harmonic. I-polarizability yesibili ye-nonlinear ye-crystal ehlanganisiwe ye-gallium selenide idlula u-170 pm/V, ephakeme kakhulu kune-polarizability yangaphakathi engaqondile ye-fiber optical. Ngaphezu kwalokho, uhlaka olude oluhlelekile lwe-crystal ye-gallium selenide luqinisekisa ukuphazanyiswa kwesigaba esiqhubekayo se-harmonics yesibili, okunikeza ukudlala okugcwele ukuze kuzuze ubude besenzo esikhulu esingaqondile ku-micro-nano fiber. Okubaluleke nakakhulu, ukufanisa isigaba phakathi kwemodi yesisekelo sokumpompa (HE11) kanye nemodi yesibili ye-harmonic high order (EH11, HE31) ibonakala ngokulawula ububanzi bekhoni bese ulawula ukuhlakazeka kwe-waveguide ngesikhathi sokulungiswa kwe-micro-nano fiber.

Izimo ezingenhla zibeka isisekelo sokuthakazelisa okusebenzayo nokubanzi kwebhendi ye-harmonics yesibili ku-micro-nano fiber. Ukuhlolwa kukhombisa ukuthi ukukhishwa kwe-harmonics yesibili ezingeni le-nanowatt kungafinyelelwa ngaphansi kwephampu ye-laser ye-1550 nm picosecond pulse, futhi i-harmonics yesibili nayo ingajatshuliswa ngokuphumelelayo ngaphansi kwephampu ye-laser eqhubekayo yobude obufanayo, futhi amandla omkhawulo anjengalokhu. aphansi njengama-microwatts angamakhulu amaningana (Umfanekiso 1). Ngaphezu kwalokho, lapho ukukhanya kwepompo kunwetshwa kumaza amathathu ahlukene e-laser eqhubekayo (1270/1550/1590 nm), ama-harmonics amasekhondi amathathu (2w1, 2w2, 2w3) namasiginali amathathu esamba sesamba (w1+w2, w1+w3, w2+) w3) zibhekwa kumaza wamaza amaza ayisithupha wokuguqulwa kwefrikhwensi. Ngokushintsha ukukhanya kwepompo ngomthombo wokukhanya we-ultra-radiant light-emitting diode (SLED) enomkhawulokudonsa ongu-79.3 nm, i-harmonic ye-wide-spectrum ebanzi enomkhawulokudonsa ongu-28.3 nm iyakhiqizwa (Umfanekiso 2). Ngaphezu kwalokho, uma ubuchwepheshe bokufaka umhwamuko wamakhemikhali bungasetshenziswa esikhundleni sobuchwepheshe bokudlulisa okomile kulolu cwaningo, futhi izingqimba ezimbalwa zamakristalu e-gallium selenide zingatshalwa ebusweni be-micro-nano fiber ngokuhamba kwamabanga amade, ukusebenza kahle kwesibili kokuguqulwa kwe-harmonic kulindeleke. ukuze ithuthukiswe.

I-FIG. 1 Isistimu yokukhiqiza i-harmonic yesibili futhi iphumela kusakhiwo se-fiber yonke

Umfanekiso 2 Ukuxutshwa kwe-Multi-wavelength kanye ne-harmonics yesibili ye-spectrum ebanzi ngaphansi kokumpompa okuqhubekayo