Yintoni i-laser ye-cryogenic

Ingcamango yeelaser ezisebenza kumaqondo obushushu aphantsi ayintsha: ilaser yesibini kwimbali yayiyinto ebangela i-cryogenic. Ekuqaleni, le ngcamango yayinzima ukuphumeza ukusebenza kwamaqondo obushushu aphantsi, kwaye umdla womsebenzi wamaqondo obushushu aphantsi waqala ngeminyaka yoo-1990 ngokuphuhliswa kweelaser ezinamandla aphezulu kunye nee-amplifier.

Ngamandla aphezuluimithombo yeleza, iziphumo zobushushu ezifana nokulahlekelwa yi-depolarization, ilensi yobushushu okanye ukugoba kwekristale yelaser kunokuchaphazela ukusebenza kweumthombo wokukhanyaNgokuphola kubushushu obuphantsi, iziphumo ezininzi eziyingozi zobushushu zinokucinezelwa ngempumelelo, oko kukuthi, i-gain medium kufuneka ipholiswe ukuya kwi-77K okanye i-4K. Isiphumo sokupholisa siquka ikakhulu:

Ukuqhuba kwe-gain medium ngendlela ephawulekayo kuthintelwe kakhulu, ikakhulu kuba indlela ephakathi ekhululekileyo yentambo iyanda. Ngenxa yoko, i-gradient yobushushu yehla kakhulu. Umzekelo, xa ubushushu buncitshiswa ukusuka kwi-300K ukuya kwi-77K, ukuqhuba kwe-thermal yekristale ye-YAG kunyuka nge-factor yesixhenxe.

I-thermal diffusion coefficient nayo iyancipha kakhulu. Oku, kunye nokuncipha kwe-gradient yobushushu, kubangela ukuba i-thermal lensing ingasebenzi kakuhle kwaye ngaloo ndlela amathuba okuqhekeka koxinzelelo anciphe.

I-thermo-optical coefficient nayo iyancitshiswa, nto leyo enciphisa ngakumbi isiphumo seelensi yobushushu.

Ukwanda kwe-absorption cross section ye-rare earth ion kubangelwa ikakhulu kukuncipha kokwandiswa okubangelwa yi-thermal effect. Ke ngoko, amandla okugcwala ayancitshiswa kwaye ukwanda kwe-laser kuyanyuswa. Ke ngoko, amandla e-threshold pump ayancitshiswa, kwaye ii-pulses ezimfutshane zinokufunyanwa xa i-Q switch isebenza. Ngokwandisa ukudluliselwa kwe-output coupler, ukusebenza kakuhle kwe-slope kunokuphuculwa, ngoko ke i-parasitic cavity loss effect ayibalulekanga kangako.

Inani lamasuntswana enqanaba eliphantsi lilonke le-quasi-three-level gain medium liyancitshiswa, ngoko ke amandla okupompa asezantsi ayancitshiswa kwaye ukusebenza kakuhle kwamandla kuyaphucuka. Umzekelo, i-Yb:YAG, evelisa ukukhanya kwi-1030nm, inokubonwa njengenkqubo ye-quasi-three-level kubushushu begumbi, kodwa inkqubo ye-four-level kwi-77K. Er: Kunjalo nakwi-YAG.

Ngokuxhomekeke kwindlela yokufumana inzuzo, ubunzulu beenkqubo ezithile zokucima ziya kuncipha.

Xa zidityaniswe nezi zinto zingasentla, ukusebenza kobushushu obuphantsi kunokuphucula kakhulu ukusebenza kwelaser. Ngokukodwa, iilaser zokupholisa kubushushu obuphantsi zinokufumana amandla aphezulu kakhulu ngaphandle kwemiphumo yobushushu, oko kukuthi, umgangatho olungileyo wemitha unokufumaneka.

Umba omnye ekufuneka uqwalaselwe kukuba kwikristale yelaser ekrwada, ububanzi bokukhanya okukhazimlisiweyo kunye nokukhanya okufunxwayo kuya kuncipha, ngoko ke uluhlu lokutshintsha ubude bomda luya kuba mncinci, kwaye ububanzi bomgca kunye nokuzinza kobude bomda welaser epompelweyo kuya kuba nzima ngakumbi. Nangona kunjalo, esi siphumo sidla ngokungaqhelekanga.

Ukupholisa okubangelwa yi-cryogenic kudla ngokusebenzisa i-coolant, efana ne-nitrogen engamanzi okanye i-helium engamanzi, kwaye ngokufanelekileyo i-refrigerant ijikeleza ngetyhubhu enamathele kwi-crystal ye-laser. I-coolant izaliswa kwakhona ngexesha okanye iphinda isetyenziswe kwi-loop evaliweyo. Ukuze kuthintelwe ukuqina, kudla ngokuba yimfuneko ukubeka i-crystal ye-laser kwigumbi le-vacuum.

Ingcamango yeekristale zelaser ezisebenza kumaqondo obushushu aphantsi ingasetyenziswa nakwizikhulisi. I-Titanium sapphire ingasetyenziselwa ukwenza i-positive feedback amplifier, amandla aphakathi okukhupha kwi-watts ezilishumi.

Nangona izixhobo zokupholisa ezibangela i-cryogenic zinokuba nzimaiinkqubo zelaser, iinkqubo zokupholisa eziqhelekileyo azisoloko zilula, kwaye ukusebenza kakuhle kokupholisa okubangelwa yi-cryogenic kuvumela ukunciphisa ubunzima.