Mhedziso ye pulsed lasers

Overview ofpulsed lasers

Nzira yakananga yekugadziralaserpulses ndeyekuwedzera modulator kune kunze kweinoenderera mberi laser.Iyi nzira inogona kuburitsa inokurumidza picosecond pulse, kunyangwe iri nyore, asi kutambisa simba rechiedza uye peak simba haigone kudarika inoenderera mwenje simba.Naizvozvo, imwe nzira yakanyatso shanda yekugadzira laser pulses ndeye kumodula mune laser cavity, kuchengetedza simba panguva isiri-yenguva yechitima chekupuruzira uye kuiburitsa panguva-nguva.Iwo mana maitiro akajairwa anoshandiswa kugadzira pulses kuburikidza nelaser cavity modulation kuwana switching, Q-switching (kurasikirwa switching), kubuda mhango, uye mode-kukiya.

Iyo yekuwana switch inogadzira mapfupi pulses nekugadzirisa simba repombi.Semuyenzaniso, semiconductor kuwana-switched lasers inogona kugadzira pulses kubva kune mashoma nanoseconds kusvika zana picoseconds nezvino modulation.Kunyangwe iyo pulse simba yakadzikira, iyi nzira inochinjika zvakanyanya, sekupa inogadziriswa yekudzokorora frequency uye pulse width.Muna 2018, vaongorori vepaYunivhesiti yeTokyo vakashuma femtosecond kuwana-inochinja semiconductor laser, inomiririra budiriro mumakumi mana-makore tekinoroji bhodhoro.

Akasimba nanosecond pulses anowanzo kugadzirwa neQ-switched lasers, ayo anoburitswa mukufamba nzendo dzinoverengeka mugomba, uye simba rekupuruzira riri muhuwandu hwemamiriyole akati wandei kusvika kune akati wandei, zvichienderana nehukuru hwehurongwa.Simba repakati (kazhinji pasi pe1 μJ) picosecond uye femtosecond pulses inogadzirwa zvikuru nemodhi-yakakiyiwa lasers.Kune imwe kana anopfuura ultrashort pulses mune laser resonator inotenderera ichitenderera.Imwe neimwe intracavity pulse inofambisa kupomba kuburikidza neinobuda coupling girazi, uye iyo refrequency inowanzo iri pakati pe10 MHz uye 100 GHz.Mufananidzo uri pazasi unoratidza zvakazara kupararira (ANDi) dissipative soliton femtosecondfiber Laser mudziyo, mazhinji ayo anogona kuvakwa uchishandisa Thorlabs standard components (fiber, lens, gomo uye displacement tafura).

Cavity emptying technique inogona kushandiswaQ-kuchinja laserskuwana mapfupi pulses uye mode-akakiyiwa lasers kuwedzera pulse simba pamwe yakaderera refrequency.

Nguva domain uye frequency domain pulses
Iyo mutsara chimiro chekupuruzira nenguva kazhinji iri nyore uye inogona kuratidzwa neGaussian uye sech² mabasa.Pulse time (inozivikanwawo se pulse width) inonyanya kuratidzwa nehhafu yehupamhi hwehupamhi (FWHM) kukosha, kureva, hupamhi pane iyo simba remaziso rinenge hafu yesimba repamusoro;Q-switched laser inogadzira nanosecond mapfupi pulses kuburikidza
Mamodhi-akakiyiwa lasers anoburitsa ekupedzisira-pfupi pulses (USP) mukurongeka kwemakumi emapicoseconds kusvika kufemtoseconds.Magetsi anomhanya-mhanya anogona chete kuyera kusvika kumakumi epicoseconds, uye mapfupi pulses anogona chete kuyerwa neyakajeka tekinoroji senge autocorrelators, FROG uye SPIDER.Nepo nanosecond kana kureba pulses isingachinji hupamhi hwekupuruzira pavanenge vachifamba, kunyangwe nenzendo refu, ultra-short pulses inogona kukanganiswa nezvinhu zvakasiyana:

Kupararira kunogona kukonzera kupuruzira kukuru, asi kunogona kudzokororwa nekupararira kwakapesana.Dhiagiramu inotevera inoratidza kuti Thorlabs femtosecond pulse compressor inotsiva sei microscope dispersion.

Nonlinearity kazhinji haina kukanganisa zvakananga kupuruzira hupamhi, asi inowedzera bandwidth, ichiita kuti iyo pulse iite nyore kupararira panguva yekuparadzira.Chero chero rudzi rwefiber, kusanganisira mamwe midhiya anowanikwa ane bandwidth mashoma, anogona kukanganisa chimiro chebhanhire kana ultra-short pulse, uye kuderera kwebhanhire kunogona kutungamirira pakuwedzera munguva;Pane zvakare zviitiko apo hupamhi hwepurusi hwepuruzi yakasimba inorira inova ipfupi kana iyo spectrum inova nhete.