Uburyo bwo Gushushanya Bessel Beam

Kugira ngo icyarimwe ibikoresho byo ku mpande zombi z'aho bihurira bishongerwe kandi bigashyiraho umugozi ukomeye cyane, aho umurongo uhuza laser ugomba kuba wibanzwe neza n'icyitegererezo, ibyo bikaba bisaba cyane uburyo bwo gutunganya neza uburyo bwo gusudira. Byongeye kandi, bitewe n'ubukana bunini bw'umuraba wa Gaussian nyuma yo gucukumbura, ubushyuhe bw'aho umurongo uhurira ntibungana, bigatuma habaho inenge ntoya n'izidafite agaciro mu gace kagizweho ingaruka na laser, ibi bikaba bigira ingaruka ku bwiza bw'icyitegererezo cyo gusudira.

Ikoranabuhanga ryo gushushanya urumuri rw'ahantu rishobora gukoreshwa mu gukora imirasire ya Bessel yo mu rwego rwa zeru kugira ngo ikwirakwizwe neza mu buryo bunoze ingufu z'umurima w'icyuma gifata urumuri. Ubu buryo bugabanya ubukana bw'imbaraga z'umurongo kandi bwongera uburebure bw'icyuma gifata urumuri, bityo byongera uburebure bw'ubujyakuzimu n'ubugari bw'agace k'ubushyuhe gakorwa na laser. Kubera iyo mpamvu, bigabanya ibisabwa mu buryo bwo gupima neza uburyo bwo gupima urumuri, bikongera ireme n'ubushobozi bwo gupima urumuri.

1. Ikorwa n'Ishusho y'Ibipimo by'Imirasire y'Ibutare Idahinduka

Mu 1987, Durnin yatanze bwa mbere igitekerezo cy’umuraba wa Bessel wo mu rwego rwa zeru, ugaragaza imiterere yihariye idahindagurika: ikwirakwizwa ryawo ry’ubukana bw’urumuri rwo mu kirere ntirihinduka mu gihe cyo gukwirakwira, kandi ingano y’ahantu hagati ihora yegereye umupaka w’aho hagati. Byongeye kandi, imiraba ya Bessel igaragaza imiterere yo kwivura ubwayo mu gihe cyo gukwirakwira. Iyo ahantu hagati habuze, urumuri ruyikikije ruzahurira hagati kugira ngo "rusane" ahantu hagati. Imiterere y’imibare y’aho umuraba wa Bessel wo mu rwego rwa zeru ukwirakwira ni:

Muri iyo mvugo:

• J0 ​igaragaza imikorere ya Bessel yo muri zeru.
• r na φ ni ibintu bya radial na angular coordinate, uko bikurikirana.
• z ni intera yo gukwirakwiza.
• Kr na Kz ni ibintu bihindura umuraba unyuranamo n'ibihindura umuraba mu gihe kirekire, uko bikurikirana.

Ahantu hakomeye hagati y’umuraba wa Bessel ufite zeru ufite ubushobozi bukomeye bwo gufunga, bigatuma imirasire y’urumuri igera kuri TW/cm² cyangwa irenga, ishobora gutuma ibikoresho birushaho kwinjiza neza. Icy'ingenzi kurushaho, ni uko imiraba ya Bessel ifite zeru itanga ubushobozi bwo gukwirakwiza ibintu mu buryo burambuye kandi ikagira ubukana buto, bityo bigatuma habaho ubushyuhe bungana kandi bigahagarika ikorwa ry’ibisembwa byo gusudira.

Ishusho ikurikira igaragaza igereranya ry'uburebure bw'imirasire ya Bessel n'imirasire ya Gaussian munsi y'ubushobozi bumwe bwo gufunga. Imirasire ya Bessel ifite uburebure bunini bwo gushimangira mu gihe igumana umurambararo w'ahantu hagenzurwa na micron.

Hari uburyo bwinshi bwo gukora imirasire ya Bessel yo mu rwego rwa zero, kandi uburyo butatu bw'ingenzi bukurikira ni bwo busanzwe:

Uburyo bwo Gupfuka Imbuto: Uburyo bwo gupfuka imbuto, nk'uko izina ribigaragaza, burimo gukoresha agace k'imbuto kugira ngo hakorwe imirasire ya Bessel. Ubu ni nabwo buryo bwa mbere bwagize ingaruka nziza mu gukora imirasire ya Bessel. Ishusho iri hepfo igaragaza uburyo bwo gupfuka imbuto mu gukora imirasire ya Bessel. Umuraba w'indege unyura ku gace k'imbuto uhereye ibumoso maze hagatangira gukwirakwira.

Nyuma yaho, lenzi nziza ikora impinduka ya Fourier, bigatuma habaho icyuma cya Bessel inyuma ya lenzi. Intera yo gukwirakwiza idahindagurika Zmax ifitanye isano n'umurambararo d w'agace k'urukiramende n'uburyo lenzi ibonamo imibare.

Nubwo ubu buryo bushobora gukora imirasire ya Bessel idakora neza, ubushobozi bwo guhindura ingufu ni buke cyane, bigatuma bigorana gukoresha mu bijyanye no gutunganya laser.

Uburyo bwo Guhindura Umucyo w'Icyaro: Uburyo bwo gukora urumuri rwa Bessel rufite umurongo wa zeru ni uburyo bwo guhindura uburyo urumuri rukwirakwira mu buryo busanzwe. Kubwibyo, urumuri rwa Bessel rufite umurongo wa zeru rushobora no gukorwa hakoreshejwe uburyo bwo guhindura urumuri rw'ahantu. Uburyo bwo guhindura urumuri rw'ahantu ni ubwoko bw'igikoresho cya optoelectronic modulation kigenzura ubukana bw'urumuri n'uburyo rukwirakwira mu buryo bunyuze mu bimenyetso by'amashanyarazi. Ububasha bwa Bessel bufite umurongo wa zeru bushobora gukorwa hakoreshejwe uburyo bwa lens bufata ibara ry'urumuri, nk'uko bigaragara ku ishusho iri hepfo, ku gice cy'akazi cya modulator y'urumuri rw'ahantu.

Uburyo bwa Axicon: Axicon ni kimwe mu bintu bikunze gukoreshwa cyane mu gukora imirasire ya Bessel. Iyo umurasire wa Gaussian ukunze kugaragara ukanyura muri axicon, ikwirakwizwa ryawo mu byiciro rirahinduka, rigahinduka umurasire wa Bessel udatakaza ingufu, nk'uko bigaragara ku ishusho iri hepfo.

Bitewe n'igiciro gito, uburyo bworoshye bwo gukoresha, hamwe n'uburyo bwo kwangiza cyane imirasire y'ibirahure, ndetse n'uburyo ikoreshwa neza cyane, imirasire ni yo mahitamo y'ibanze yo gukora imirasire ya Bessel mu buryo bugufi cyane mu bijyanye no gutunganya imirasire ya Bessel. Ishusho iri hepfo igaragaza ishusho y'uburyo imirasire igabanuka kandi igahererekanywa n'umurasire wa Bessel udafite gahunda. Mu guhindura uburyo bwo kongera no kwerekeza amashusho ya 4f, intera yo gukwirakwiza idahindagurika, inguni ya kimwe cya kabiri cy'umurasire, n'inguni yo kuzunguruka mu cyerekezo cyo gukwirakwiza imirasire ya Bessel bishobora kugenzurwa byoroshye.

Iyo umurimbo wa Bessel ugizwe na zeru ufite inguni ya Ɵ1 n'intera ya Zmax idafite diffraction inyura muri sisitemu ya 4f igizwe na lens (L1) na lens ishingiye ku ntego (L2), ingano za geometrike zizakomeza gukandamizwa. Ingufu zo ku ruhande ni hafi M=f1/f2=5, naho ingufu zo ku ruhererekane ni hafi M2=25. Bityo, ishusho ya nyuma y'umurimbo wa Bessel ugizwe na zeru iri mu rugero ishobora gugaragazwa n'ibipimo bya geometrike:

Ibipimo bya jeometrike by'umuraba wa Bessel byafashwe mu gishushanyo cy'ikirahure cya quartz munsi y'inguni zitandukanye z'amakone n'ubwiyongere bw'umuraba.

Ikwirakwizwa ry'ubukana bw'umuraba wa Bessel mu gice cyo hagati cy'ibyiciro

• r na z: Ibice bya radial na axial coordinate, uko bikurikirana.
• λ: Uburebure bw'uburebure bwo hagati bwa laser.
• w: 1/e² y'umuraba wa Gaussian wabaye.
• P0: Ingufu nyinshi za laser ya pulse ngufi cyane.
• β1: Inguni y'igice cy'umuraba wa Bessel nyuma yo gukandagira umuraba.
• k: Vektori y'umuraba.
• J0: Umukorere wa Bessel wo muri Zero-order.

Ingano y'ubukana bw'umuraba wa Bessel uri mu kirahuri cya quartz: Ibumoso hari ikwirakwizwa ry'ubucucike bw'ingufu z'urumuri ku cyerekezo cyo gukwirakwiza n'icyerekezo cyambukiranya, naho iburyo hari ikwirakwizwa ry'ubucucike bw'ingufu z'urumuri ku ruhande rw'umurongo n'icyerekezo cyambukiranya.

2. Ibiranga Femtosecond Pulse Bessel Beam muri Fused Silica Glass

Ishusho (a) igaragaza mikorografi z'imikoranire hagati y'imirasire ya femtosecond pulse Bessel beams na fused silica glass ku ngufu zitandukanye za pulse. Ubugari bwa laser pulse buhagaze kuri 220 fs, kandi inguni ya kimwe cya kabiri cy'umurasire wa Bessel imbere mu gipimo ni 12.4°. Bigaragara ko agace kagizweho ingaruka na laser gagaragaza imiterere isanzwe y'umurongo umwe. Iyo ingufu za laser pulse ziri munsi ya 9.5 μJ, igipimo cyo kurekura cy'ibintu biri mu gace k'ibanze kiriyongera, kikagaragara nk'agace k'umukara muri mikorografi.

Iyo ingufu za laser pulse zirenze 9.5 μJ, igipimo cyo kugarura urumuri (refractive index) cy'ibintu biri mu gace k'ibanze kiragabanuka, kikagaragara nk'agace k'umweru muri mikorografi, kandi uburebure bw'agace k'umweru bwiyongera uko ingufu za pulse ziyongera. Mu gukosora icyitegererezo, twabonye imiterere y'agace k'umweru ku ngufu za pulse za 15.4 μJ munsi ya mikorosikopi ya elegitoroniki yo gushakisha, nk'uko bigaragara ku Ishusho (b). Byafatwa umwanzuro ko nanopore ifite umurambararo wa hafi 200 nm ibaho mu gace kafite igipimo cyo kugarura urumuri cyagabanutse.

Binyuze mu gushushanya imirasire ya ion no gupima mikorosikopi ya elegitoroniki, twemeje ko hari nanopore (Ishusho ya c). Kubwibyo, kugira ngo tugabanye ingaruka mbi ziterwa na laser, ingufu za pulse imwe ntizigomba kurenza 9.5 μJ mu gihe cyo gusudira laser.

3. Kugera ku busudizi bw'ubuziranenge hagati y'indorerwamo za silica zivanze hakoreshejwe Bessel Ultrashort Pulse Laser.

Ishusho (a) igaragaza mikorografi igaragara hejuru y'ubuso bw'icyitegererezo. Bigaragara ko umurongo wa laser weld umeze kimwe kandi woroshye. Nubwo hakiri inenge nke za mikoroporo zikwirakwira mu gace gasutswe, muri rusange, ni nziza cyane kurusha umurongo wa laser weld wa Gaussian. Ibipimo bigaragaza ko ubugari bw'umurongo wa weld ari hafi 18 μm, kandi intera iri hagati y'imirongo ya weld ni 40 μm. Ishusho (b) igaragaza mikorografi igaragara ku ruhande rw'umurongo wa weld w'icyitegererezo.

Bigaragara ko icyuho kiri hagati y’ibipimo kibura burundu nyuma yo gutunganya laser, kandi ibikoresho biri hafi y’aho bihurira byahujwe mu kintu kimwe nyuma yo gukora igikorwa cyo gukonjesha no gushonga. Ibipimo bigaragaza ko uburebure bw’agace k’ubushyuhe buterwa na laser bugera kuri μm 227. Ibi bigaragaza ko mu gihe cyo gusudira laser hakoreshejwe ibi bipimo, uburebure bw’umurongo w’imbere bushobora kugera kuri μm 227, bikubye inshuro enye ugereranyije n’ubushyuhe bwa laser ya Gaussian mu bihe bimwe.

4. Ni hehe wagura amalensi ya Bessel?

Wavelength Opto-Electronic itanga lenses nziza za Bessel zikoreshwa mu gutunganya laser. Uburyo bwo guhindura uburebure bw'umuraba usohoka hakoreshejwe guhindura ingano y'umurambararo w'umuraba winjira ni cyo kintu gikurura cyane iyi sisitemu ya Bessel optique.