Uhlolojikelele lwama-lasers we-pulsed

Uhlolojikelele lwei-pulsed lasers

Indlela eqondile kakhulu yokukhiqizalaseri-pulses iwukwengeza i-modulator ngaphandle kwelaser eqhubekayo. Le ndlela ingakhiqiza i-picosecond pulse eshesha kakhulu, nakuba ilula, kodwa imoshe amandla okukhanya namandla aphakeme ayikwazi ukudlula amandla okukhanya aqhubekayo. Ngakho-ke, indlela esebenza kahle kakhulu yokukhiqiza ama-laser pulses iwukumodela endaweni ye-laser, ukugcina amandla ngesikhathi esingekho sesitimela esishayelayo futhi siwakhiphe ngesikhathi. Izindlela ezine ezijwayelekile ezisetshenziselwa ukukhiqiza ama-pulses ngokusebenzisa i-laser cavity modulation ukushintshwa kwenzuzo, ukushintsha kwe-Q (ukulahlekelwa ukushintsha), ukukhipha umgodi, kanye nokukhiya imodi.

Ukushintsha kwenzuzo kukhiqiza ama-pulses amafushane ngokumodela amandla epompo. Isibonelo, ama-lases ashintshwayo e-semiconductor angakwazi ukukhiqiza ama-pulses ukusuka kuma-nanosecond ambalwa ukuya kuma-picoseconds ayikhulu ngokushintshashintsha kwamanje. Nakuba amandla okushaya kwenhliziyo ephansi, le ndlela ivumelana nezimo kakhulu, njengokuhlinzeka imvamisa yokuphindaphinda okulungisekayo kanye nobubanzi bokushaya kwenhliziyo. Ngo-2018, abacwaningi eNyuvesi yaseTokyo babika nge-laser ye-semiconductor eshintshiwe ye-femtosecond, emele impumelelo ebhodleleni lobuchwepheshe leminyaka engama-40.

Ama-nanosecond pulses aqinile ngokuvamile akhiqizwa ama-lasers ashintshiwe ka-Q, akhishwa ohambweni oluthile lokuzungeza emgodini, futhi amandla okushaya kwenhliziyo asebangeni lama-millijoules ambalwa ukuya kuma-joule amaningana, kuye ngosayizi wesistimu. Amandla amaphakathi (ngokuvamile ngaphansi kuka-1 μJ) ama-picosecond kanye nama-femtosecond pulses akhiqizwa ikakhulukazi ama-laser akhiywe ngemodi. Kukhona i-ultrashort pulses eyodwa noma ngaphezulu ku-laser resonator ejikeleza ngokuqhubekayo. I-Intracavity pulse ngayinye idlulisa ukushaya kwenhliziyo ngesibuko esihlanganisa okukhiphayo, futhi imvamisa imvamisa iphakathi kuka-10 MHz no-100 GHz. Isibalo esingezansi sibonisa i-soliton femtosecond evamile ngokuphelele yokuhlakazeka (ANDi).idivayisi ye-fiber laser, iningi lazo elingakhiwa kusetshenziswa izakhi ezijwayelekile ze-Thorlabs (fiber, lens, mount and displacement table).

I-cavity emptying technique ingasetshenziselwaAmalaser ashintshiwe nge-Qukuthola ama-pulses amafushane nama-lasers akhiywe kwimodi ukuze kukhuliswe amandla okushaya kwenhliziyo nge-refrequency ephansi.

Isizinda sesikhathi nama-pulses wesizinda semvamisa
Umumo womugqa wokushaya kwenhliziyo ngesikhathi ngokuvamile ulula futhi ungavezwa ngemisebenzi ye-Gaussian kanye ne-sech². Isikhathi se-Pulse (esaziwa nangokuthi ububanzi be-pulse) sivame ukuvezwa ivelu yobubanzi obuyingxenye yobude (FWHM), okungukuthi, ububanzi lapho amandla okubona afinyelela khona okungenani uhhafu wamandla aphezulu; I-laser eshintshwayo ye-Q ikhiqiza i-nanosecond short pulses ngokusebenzisa
Ama-laser akhiywe kumodi akhiqiza ama-ultra-short pulses (USP) ngokulandelana kwamashumi ama-picoseconds ukuya kuma-femtoseconds. Ama-electronics anesivinini esikhulu angakala kuphela amashumi ama-picoseconds, futhi ama-pulse amafushane angalinganiswa kuphela ngobuchwepheshe be-optical obufana nama-autocorrelators, FROG kanye ne-SPIDER. Ngenkathi ama-nanosecond noma ama-pulses amade angakwazi ukushintsha ububanzi be-pulse yawo njengoba ehamba, ngisho nasezindaweni ezide, ama-ultra-short pulses angathinteka yizinto ezihlukahlukene:

Ukuhlakazeka kungabangela ukushaya kwenhliziyo okukhulu, kodwa kungacindezelwa futhi ngokuhlakazeka okuphambene. Umdwebo olandelayo ubonisa ukuthi i-Thorlabs femtosecond pulse compressor inxephezela kanjani ukusabalalisa ngesibonakhulu.

I-nonlinearity ngokuvamile ayithinti ngokuqondile ububanzi be-pulse, kodwa ikhulisa umkhawulokudonsa, okwenza ukushaya kwenhliziyo kube lula ukuhlakazeka ngesikhathi sokusakazeka. Noma yiluphi uhlobo lwefiber, kuhlanganise nezinye imidiya yokuzuza enomkhawulokudonsa olinganiselwe, zingathinta ukuma komkhawulokudonsa noma i-ultra-short pulse, futhi ukwehla komkhawulokudonsa kungaholela ekwandiseni isikhathi; Kukhona futhi izimo lapho ububanzi be-pulse ye-pulse etshiyoza ngamandla buba bufushane lapho i-spectrum iba mincane.