Amagqabantshintshi ngeelaser zepulsed

Isishwankathelo sei-pulsed lasers

Eyona ndlela ithe ngqo yokuvelisalaseriipulses kukongeza imodyuli ngaphandle kwelaser eqhubekayo. Le ndlela inokuvelisa i-picosecond pulse ekhawulezayo, nangona ilula, kodwa inkunkuma yamandla okukhanya kunye namandla aphezulu ayinakudlula amandla okukhanya aqhubekayo. Ke ngoko, indlela esebenzayo ngakumbi yokuvelisa i-laser pulses kukumodareyitha kwi-laser cavity, ukugcina amandla ngexesha elingekho kuloliwe we-pulse kwaye uyikhulule ngexesha. Iindlela ezine eziqhelekileyo ezisetyenziselwa ukuvelisa i-pulses ngokusebenzisa i-laser cavity modulation kukutshintsha kwenzuzo, ukutshintshwa kwe-Q (ilahleko yokutshintsha), ukukhupha umbhobho, kunye nokuvalwa kwendlela.

Ukutshintsha inzuzo kuvelisa iipulses ezimfutshane ngokumodareyitha amandla empompo. Ngokomzekelo, i-semiconductor gain-switched lasers inokuvelisa i-pulses ukusuka kwii-nanoseconds ezimbalwa ukuya kwikhulu le-picoseconds ngokumodareyitha kwangoku. Nangona amandla e-pulse ephantsi, le ndlela iguquguquka kakhulu, njengokubonelela ngokuphindaphinda okuphindaphindiweyo kunye nobubanzi be-pulse. Ngo-2018, abaphandi kwiYunivesithi yaseTokyo babika i-laser ye-semiconductor ye-femtosecond, emele impumelelo kwi-bottleneck yezobuchwepheshe ye-40.

Iipulses ezinamandla ze-nanosecond ngokubanzi ziveliswa ngama-lasers a-Q-switched, akhutshwa kwiihambo ezininzi ezijikelezayo kwi-cavity, kwaye i-pulse energy ikuluhlu lwee-millijoules ezininzi ukuya kwii-joules ezininzi, kuxhomekeke kubukhulu benkqubo. Amandla aphakathi (ngokubanzi ngaphantsi kwe-1 μJ) i-picosecond kunye ne-femtosecond pulses iveliswa ikakhulu yi-mode-locked lasers. Kukho enye okanye ngaphezulu i-ultrashort pulses kwi-laser resonator ejikeleza ngokuqhubekayo. I-Intracavity pulse nganye ihambisa i-pulse ngesipili sokudibanisa imveliso, kwaye i-refrequency iphakathi kwe-10 MHz kunye ne-100 GHz. Lo mzobo ungezantsi ubonisa i-dispersion eqhelekileyo ngokupheleleyo (ANDi) dissipative soliton femtosecondisixhobo se-fiber laser, uninzi lwayo lunokwakhiwa kusetyenziswa amacandelo asemgangathweni we-Thorlabs (ifayibha, ilensi, intaba kunye netafile yokufuduswa).

Indlela yokukhupha i-Cavity ingasetyenziselwaQ-utshintshe i-lasersukufumana iipulses ezimfutshane kunye ne-mode-lock lasers ukunyusa amandla e-pulse kunye ne-refrequency ephantsi.

Ixesha lommandla kunye ne-frequency domain pulses
Ubume bomgca we-pulse kunye nexesha ngokubanzi lulula kwaye lunokubonakaliswa yiGaussian kunye nemisebenzi ye-sech². Ixesha le-Pulse (elikwaziwa ngokuba yi-pulse width) lidla ngokubonakaliswa yi-half-height wide (FWHM) ixabiso, oko kukuthi, ububanzi apho amandla okukhanya angaphantsi kwesiqingatha samandla aphezulu; I-laser etshintshiweyo ye-Q yenza i-nanosecond pulses emfutshane
Iilaser ezitshixwayo kwimowudi zivelisa i-ultra-short pulses (USP) ngokolandelelwano lwamashumi eepicoseconds ukuya kwi-femtoseconds. Isantya esiphezulu sombane sinokulinganisa amashumi eepicoseconds kuphela, kwaye iipulse ezimfutshane zinokulinganiswa kuphela ngobuchwephesha bokukhanya obufana ne-autocorrelators, FROG kunye ne-SPIDER. Ngelixa i-nanosecond okanye ii-pulses ezinde zingenakukwazi ukutshintsha ububanzi bazo be-pulse njengoko zihamba, nangaphezu kwemigama emide, ii-pulses ezifutshane kakhulu zinokuchatshazelwa zizinto ezahlukeneyo:

Ukusasazwa kunokubangela ukubethelwa kwe-pulse enkulu, kodwa kunokunyanzeliswa kunye nokusasazwa okuchaseneyo. Lo mzobo ulandelayo ubonisa indlela iThorlabs femtosecond pulse compressor ibuyekeza ngayo ukusasazwa kwemicroscope.

Ukungahambelani ngokuqhelekileyo akuchaphazeli ngokuthe ngqo ububanzi be-pulse, kodwa kwandisa i-bandwidth, okwenza i-pulse ithinteke ngakumbi ekuhlakazeni ngexesha lokusasazwa. Naluphi na uhlobo lwefiber, kubandakanywa nezinye i-media ezifumana i-media kunye ne-bandwidth elinganiselwe, inokuchaphazela ukuma kwe-bandwidth okanye i-ultra-short pulse, kunye nokuncipha kwe-bandwidth kunokukhokelela ekwandiseni ixesha; Kukwakho iimeko apho i-pulse ububanzi be-pulse ekhatywa ngamandla iba mfutshane xa i-spectrum iba mxinwa.