Isizukulwana seVector Vortex Inaliti yeMiqadi kunye nokuSasazwa kwabo kwi-Trbulent Atmosphere

I-Atmospheric turbulence isoloko ibeka umngeni omkhulu ekusasazeni okuzinzile kwee-lasers, ngokukodwa ukuhanjiswa kwexesha elide kwiinkqubo zonxibelelwano lwe-free-space optical (FSOC). Ukunciphisa iziphumo ezibi ze-atmospheric turbulence, kukho imfuneko engxamisekileyo yokuphuhlisa imiqadi ye-optical ekhethekileyo.

Ulwazi lwePhepha:

Kolu phononongo, iimpawu zokusasaza zeVector Vortex Needle Beams (VVPBs) kwindawo ekhululekileyo zihlalutywa ngokwethiyori kwaye zithathwe, kunye nokuziphatha kwazo kwisiphithiphithi se-atmospheric esilinganiswe ngamanani. Iziphumo zokulinganisa zibonisa ukuba phantsi kweemeko ezifanayo, ii-VVPB zibonisa i-scintillation indices ephantsi kunye ne-beam engaphantsi kwe-beam ejikelezayo kuneeBeams eziqhelekileyo ze-Pinhole (PBs) ngexesha lokuhanjiswa kwexesha elide. Ukongeza, zombini ii-VVPBs kunye nee-PBs zenziwe ngokomfuniselo, kwaye izalathiso zazo ze-scintillation kunye ne-beam wander zilinganiswa kwindawo yelabhoratri enesiphithiphithi esibangelwa yi-thermal. Idatha yokuvavanya iqinisekisa ukufunyaniswa kweengcamango, iqinisekisa ukuba ii-VVPB zineenzuzo ezibalulekileyo ekunciphiseni imiphumo ye-turbulence. Ezi ziphumo kulindeleke ukuba zibe neempembelelo ezibalulekileyo kuphuhliso lonxibelelwano lwe-optical indawo yasimahla kunye nobuchwepheshe bokubona kude.

Oku kulandelayo ngamalungu eenkqubo zovavanyo kunye neziphumo:

Ukuqinisekisa iziphumo zethiyori, saqala ngokulinga ii-VVPB kunye nee-PBs, kwaye emva koko silinganise amandla azo okusasaza kwindawo enesiphithiphithi. Ukuseta umfuniselo kuboniswe kumzobo ongezantsi. Umqadi welaser owenziwe ngomgca we-laser kwi-532 nm wandiswa kwaye emva koko wahlulwa kwiindlela ezimbini nge-50:50 ye-beam splitter (BS1) ukwenza i-interferometer ye-Mach-Zehnder. Ukukhanya kwindlela nganye kubonakaliswe yi-modulator yokukhanya kwendawo yesigaba kuphela (SLM) ukulungelelanisa isigaba kunye ne-amplitude ye-beam yesiganeko. Imiqadi ehlengahlengisiweyo idlule kwiinkqubo ezimbini ze-4f, ezibonisa ukukhanya kwinqwelomoya yokugqibela yenkqubo ye-4f enokukhulisa ubunye. Iinqwelomoya zokugqibela zenkqubo nganye ye-4f zaye zadityaniswa ngokugqibeleleyo kwi-BS4, enokuthi ithathwe njengomthombo wendiza. Iilensi ezimbini ze-cylindrical (i-CA1 kunye ne-CA2) zibekwe kwiiplani ezigxininisiweyo ze-lens ze-L1 kunye ne-L3, ngokulandelanayo, ukucoca imiyalelo engafunekiyo ye-diffraction kunye nengxolo yangasemva. Ukukhanya okuphuma kwi-BS4 kwenze umqadi omnye odlula kwipleyiti eshushu ukuvelisa isiphithiphithi. Emva kokudlula kwi-plate evuthayo, i-beam irekhodwe ngesixhobo esidibeneyo (CCD). Iihologram ezifakwe kwiiSLM ezimbini zenziwe ngekhompyutha. I-amplitude kunye nesigaba kwii-SLM ezimbini ziyafana, ngaphandle kokuba isigaba esongezelelweyo π/2 salayishwa kwi-SLM2. Oku kwenza ukukhanya kubonakaliswe kwii-SLM kwiindlela ze-1 kunye ne-2 ye-orthogonal, evumela ukubunjwa kwe-VVPBs. Ukongeza, ngokuvala indlela enye kunye nokutshintsha ihologram, iiPBs nazo zinokuveliswa. Ke ngoko, olu cwangciso lovavanyo lwenza ukuba isizukulwana esifanelekileyo seVVPBs kunye neePBs.

Umfanekiso woku-1Ukusekwa kovavanyo lokuvelisa ii-VVPB kunye nokuphanda ukusasazwa kwazo kwiindawo eziphazamisayo, kubandakanywa i-expander ye-beam (BE), iilensi (L1-L4), i-charge-coupled device (CCD), i-beam splitters (BS), i-modulators yokukhanya kwendawo (SLM1 kunye ne-SLM2), kunye ne-circular apertures (CA1 kunye ne-CA2).

Umfanekiso wesi-2Ukuthelekiswa phakathi kweziphumo zokulinganisa (umqolo wokuqala) kunye neziphumo zokuhlalutya (umqolo wesibini) wokusabalalisa ukuqina okuqhelekileyo kwi-VVPBs kwi-z = 400 mm indiza. Umqolo wesithathu ubonisa uthelekiso lwamacandelo phakathi komqolo wokuqala nowesibini. Ikholamu yokuqala ibonisa ubunzulu obupheleleyo, ikholamu yesibini ibonisa i-x-component, kwaye ikholamu yesithathu ibonisa u-y-component. Ibha emhlophe ibonisa i-3 mm. Amanani (a) ukuya ku-(f) anemilinganiselo efanayo.

Umzobo 3Ibonisa imodeli yokulinganisa yee-VVPBs ezisasazeka kwindawo enesiphithiphithi.

Umzobo 4Ukuguquguquka kwe-Axial intensity ye-VVPBs (umqolo wokuqala) kunye ne-PBs (umqolo wesibini) phantsi kobunzima obuhlukeneyo besiphithiphithi.

Umfanekiso wesi-5Ukuhanjiswa kwe-Beam centroid ukusuka kwi-1000 intensity realizations ye-VVPBs (umqolo wokuqala) kunye ne-PBs (umqolo wesibini) kwii-turbulence intensities ezahlukeneyo.

Umfanekiso wesi-6Iindawo ze-Beam ze-VVPB ezirekhodwe yi-analyzer yeprofayili ye-beam kwindawo ekhululekile kwi-1 m ukusuka kwi-BS4: (a) ukusabalalisa ubuninzi obupheleleyo, (b) i-x-component, kunye (c) ne-y-component. Iphaneli nganye inomlinganiselo omalunga ne-7×5 mm².

Umzobo 7Iziphumo zovavanyo ezibonisa ukuhluka kwe (a) isalathisi se-scintillation kunye (b) ne-beam wander kunye nobushushu bepleyiti eshushu kuzo zombini ii-PB kunye ne-VVPB.

Iiparamitha kunye neenkcukacha zohlobo lwesigaba semodyuli yokukhanya kwendawo esetyenziswe kolu vavanyo lulandelayo:

Qaphela: Iimodeli ezahlukeneyo ziyahluka kwinqanaba lokumodareyitha kunye nokusetyenziswa kokukhanya. Ngeemfuno ezithile, nceda uqhagamshelane nomphathi wentengiso kwingingqi yakho ngeenkcukacha.

Ingxelo yokugqibela:

I-spatial light modulator (SLM) sisixhobo esingundoqo se-optoelectronic esisebenzisa i-electro-optic effect ye-liquid crystal materials ukulawula ngokuguquguqukayo ukusasazwa kwendawo yamaza okukhanya (kubandakanya i-amplitude, isigaba, okanye i-polarization). Njengesixhobo esinamandla kakhulu kwi-optics yanamhlanje kunye neefotonics, yenza kube lula, ukuchaneka, kunye nokuguqulwa okuguquguqukayo kokusasazwa kokukhanya esithubeni. Okwangoku, iindlela eziphambili zokuvelisa imiqadi ye-vortex ziquka indlela yepleyiti yesigaba sokuvunguza, imodyuli yokukhanya kwendawo, ihologram eyenziwe ngekhompyutha, indlela yokuguqula imo, i-metasurface, njl.

Ulwazi lwenqaku:

https://doi.org/10.1063/5.0248643