Incamake ya lasers zikoresha pulse

Incamake yalaser zikoresha pulse

Uburyo butaziguye bwo gukoralaserpulses ni ukongeramo modulator inyuma ya laser ikomeza. Ubu buryo bushobora gukora picosecond pulse yihuta cyane, nubwo byoroshye, ariko ingufu z'urumuri zipfa ubusa n'imbaraga zo hejuru ntibishobora kurenza imbaraga z'urumuri ruhoraho. Kubwibyo, uburyo bwiza bwo gukora pulses za laser ni uguhindura mu cyuho cya laser, kubika ingufu mu gihe kitari cyo mu cyuho cy'umurongo w'ingufu no kuzirekura ku gihe. Uburyo bune busanzwe bukoreshwa mu gukora pulses binyuze mu guhindura ikirere cya laser ni uguhindura ikirere, guhindura Q (guhindura ikirere), gusohora igicucu, no gufunga ikirere.

Ingufu zo gupima amashanyarazi zitanga imivuduko migufi binyuze mu guhindura imbaraga za pompe. Urugero, laser zikoresha uburyo bwa semiconductor gain-switched zishobora gukora imivuduko kuva kuri nanosegonda nke kugeza kuri picosegonda ijana binyuze mu buryo bwa current modulation. Nubwo ingufu za pulse ari nke, ubu buryo buragoye cyane, nko gutanga frequency ihinduka isubiramo n'ubugari bwa pulse. Mu 2018, abashakashatsi bo muri Kaminuza ya Tokyo batangaje ko laser ya semiconductor ya femtosecond gain-switched, igaragaza iterambere mu nzitizi y'ubuhanga yamaze imyaka 40.

Imivuduko ikomeye ya nanosecond muri rusange ikorwa na lazeri za Q-switched, zisohoka mu ngendo nyinshi zizenguruka mu mwobo, kandi ingufu za pulse ziri hagati ya millijoule nyinshi na joule nyinshi, bitewe n'ingano y'iyi sisitemu. Ingufu ziciriritse (muri rusange ziri munsi ya 1 μJ) picosecond na femtosecond ahanini zikorwa na lazeri za mode-locked. Hariho imivuduko imwe cyangwa myinshi ya ultrashort muri resonator ya lazeri izenguruka buri gihe. Buri mivuduko ya intracavity yohereza pulse binyuze mu ndorerwamo ihuza umusaruro, kandi isubiramo muri rusange riri hagati ya 10 MHz na 100 GHz. Ishusho iri hepfo igaragaza dispersion isanzwe (ANDi) dissipative soliton femtosecondigikoresho cya laser ya fibre, inyinshi muri zo zishobora kubakwa hakoreshejwe ibice bisanzwe bya Thorlabs (fibre, lens, mount na displacement table).

Uburyo bwo gukuramo imyobo mu mwobo bushobora gukoreshwa kuriImashini za laser zikoresha Q-switchedkubona imivuduko migufi na lazeri zifunganye kugira ngo wongere ingufu z'imivuduko hamwe no kugabanuka guke.

Imiterere y'aho ibintu biherereye n'impinduka z'aho ibintu biherereye
Imiterere y'umurongo w'umuvuduko w'amaraso ukurikije igihe muri rusange yoroshye cyane kandi ishobora kugaragazwa n'imikorere ya Gaussian na sech². Igihe cy'umuvuduko w'amaraso (kizwi kandi nka pulse width) gikunze kugaragazwa n'agaciro k'ubugari bwa kimwe cya kabiri cy'uburebure (FWHM), ni ukuvuga ubugari aho imbaraga z'amatara ziba nibura kimwe cya kabiri cy'imbaraga z'umuvuduko w'amashanyarazi; laser ya Q-switched ikora imivuduko migufi ya nanosecond binyuze muri
Imashini zikoresha uburyo bwa "mode-locked lasers" zikora "ultra-short pulses" (USP) mu buryo bwa "picoseconds" icumi na "femtoseconds". Ikoranabuhanga ryihuse rishobora gupima "picoseconds" icumi gusa, kandi "pulses" ngufi zishobora gupimwa gusa hakoreshejwe ikoranabuhanga rya optique gusa nka "autocorrelators", "FROG" na "SPIDER". Nubwo "nanosecond" cyangwa "long pulses" zidahindura ubugari bwa "pulse" mu gihe zigenda, ndetse no mu ntera ndende, "ultra-short pulses" zishobora kugira ingaruka ku bintu bitandukanye:

Gutatana bishobora gutuma umuvuduko munini w'amaraso ugenda waguka, ariko bishobora kongera gukandamizwa hamwe n'uburyo butandukanye. Ishusho ikurikira igaragaza uburyo Thorlabs femtosecond pulse compressor igabanya itatana rya mikorosikopi.

Ubusanzwe kudahuza umurongo n'umurongo (Nonlinearity) ntabwo bigira ingaruka ku bugari bw'imitsi, ariko byongera umuvuduko w'ingufu, bigatuma umuvuduko w'ingufu ukwirakwira mu gihe cyo gukwirakwira. Ubwoko ubwo aribwo bwose bwa fibre, harimo n'ubundi buryo bwo gukwirakwiza umuvuduko w'ingufu bufite umuvuduko muto, bushobora kugira ingaruka ku miterere y'umuvuduko w'ingufu cyangwa umuvuduko muke cyane, kandi kugabanuka k'umuvuduko w'ingufu bishobora gutuma igihe kigenda gihita; Hari kandi n'igihe ubugari bw'umuvuduko w'ingufu zishyushye cyane buba bugufi iyo umuvuduko w'ingufu ugabanutse.