N’chifukwa chiyani tiyenera kudziwa mfundo ya lasers?
Kudziwa kusiyana pakati pa semiconductor wamba lasers, ulusi, zimbale, ndiYAG laserzingathandizenso kumvetsetsa bwino ndikuchita nawo zokambirana zambiri panthawi yosankha.
Nkhaniyi imangoyang'ana kwambiri pa sayansi yodziwika bwino: mawu oyamba achidule a mfundo ya m'badwo wa laser, kapangidwe kake ka ma lasers, ndi mitundu ingapo wamba ya lasers.
Choyamba, mfundo ya m'badwo laser
Laser amapangidwa mwa kuyanjana pakati pa kuwala ndi zinthu, zomwe zimadziwika kuti kukulitsa ma radiation; Kumvetsetsa kukwezedwa kwa ma radiation kumafuna kumvetsetsa malingaliro a Einstein a kutulutsa kochitika modzidzimutsa, kuyamwa kokondoweza, ndi cheza chokondoweza, komanso maziko ena ofunikira.
Zongopeka Maziko 1: Bohr Model
Mtundu wa Bohr makamaka umapereka mawonekedwe amkati a maatomu, kupangitsa kuti zikhale zosavuta kumvetsetsa momwe ma laser amachitikira. Atomu imapangidwa ndi nyukiliyasi ndi ma elekitironi kunja kwa phata, ndipo ma orbitals a ma elekitironi samangokhalira kusuntha. Ma elekitironi ali ndi ma orbital okha, omwe mkati mwa orbital amatchedwa dziko lapansi; Ngati electron ili pansi, mphamvu yake ndi yotsika kwambiri. Ngati electron ikudumpha kuchokera ku orbit, imatchedwa dziko loyamba lokondwa, ndipo mphamvu ya dziko loyamba lokondwa lidzakhala lalitali kuposa la dziko lapansi; Njira ina imatchedwa dziko lachisangalalo lachiwiri;
Chifukwa chomwe laser imatha kuchitika ndi chifukwa ma elekitironi amasuntha m'njira zosiyanasiyana munjira iyi. Ngati ma electron amatenga mphamvu, amatha kuthamanga kuchokera pansi kupita kumalo okondwa; Ngati electron ibwerera kuchokera ku dziko lokondwa kupita ku dziko lapansi, idzatulutsa mphamvu, yomwe nthawi zambiri imatulutsidwa ngati laser.
Theoretical Basis 2: Einstein's Stimulated Radiation Theory
Mu 1917, Einstein adapereka chiphunzitso cha radiation yolimbikitsa, yomwe ndi maziko owerengera ma lasers ndi laser kupanga: kuyamwa kapena kutulutsa zinthu kumakhala chifukwa cha mgwirizano pakati pa gawo la radiation ndi tinthu tating'onoting'ono tomwe timapanga zinthu, komanso maziko ake. kwenikweni ndi kusintha kwa particles pakati pa magulu osiyanasiyana amphamvu. Pali njira zitatu zosiyana polumikizana pakati pa kuwala ndi zinthu: kutulutsa kochitika, kutulutsa kosonkhezeredwa, ndi kuyamwa mosonkhezeredwa. Kwa dongosolo lomwe lili ndi tinthu tambirimbiri, njira zitatuzi zimakhalapo nthawi zonse ndipo zimagwirizana kwambiri.
Kutulutsa kochitika:
Monga momwe chithunzichi chikusonyezera: electron pa mlingo wapamwamba wa mphamvu E2 imasintha mwadzidzidzi ku mlingo wochepa wa mphamvu E1 ndipo imatulutsa photon ndi mphamvu ya hv, ndi hv = E2-E1; Kusintha kwachisawawa ndi kosagwirizana kumeneku kumatchedwa kusintha kwachisawawa, ndipo mafunde a kuwala omwe amatulutsidwa ndi kusintha kodzidzimutsa amatchedwa kuwala kochitika modzidzimutsa.
Makhalidwe a kutulutsa kochitika modzidzimutsa: Photon iliyonse imakhala yodziyimira payokha, yokhala ndi mayendedwe ndi magawo osiyanasiyana, ndipo nthawi yochitika imakhalanso mwachisawawa. Ndi kuwala kosagwirizana ndi chipwirikiti, komwe sikuli kuwala kofunikira ndi laser. Chifukwa chake, njira yopangira laser iyenera kuchepetsa kuwala kosokera kwamtunduwu. Ichi ndi chimodzi mwazifukwa zomwe kutalika kwa ma lasers osiyanasiyana kumakhala ndi kuwala kosokera. Ngati ziwongoleredwa bwino, gawo la kutulutsa kwadzidzidzi mu laser likhoza kunyalanyazidwa. Laser yoyera, monga 1060 nm, yonse ndi 1060 nm, Laser yamtundu uwu imakhala ndi kukhazikika kokhazikika komanso mphamvu.
Kukoka mayamwidwe:
Ma electron pamagulu otsika a mphamvu (otsika orbitals), atatha kuyamwa ma photon, kusintha kwa mphamvu zapamwamba (ma orbitals apamwamba), ndipo njirayi imatchedwa stimulated mayamwidwe. Mayamwidwe olimbikitsidwa ndi ofunikira komanso imodzi mwazinthu zazikulu zopopa. Gwero la mpope la laser limapereka mphamvu ya photon kuti ipangitse tinthu tating'onoting'ono tomwe titha kusintha ndikudikirira ma radiation olimbikitsidwa pamilingo yamphamvu kwambiri, kutulutsa laser.
Ma radiation olimbikitsa:
Mukayatsidwa ndi kuwala kwa mphamvu zakunja (hv = E2-E1), electron pa mlingo wapamwamba wa mphamvu imakondwera ndi photon yakunja ndikudumphira ku mphamvu yochepa (yokwera kwambiri imathamangira kumalo otsika). Panthawi imodzimodziyo, imatulutsa photon yomwe ili yofanana ndi photon yakunja. Izi sizimamwa kuwala koyambirira kosangalatsa, kotero padzakhala mafotoni awiri ofanana, omwe amatha kumveka ngati ma elekitironi amalavulira photon yomwe idalowetsedwa kale, Njira iyi ya luminescence imatchedwa ma radiation olimbikitsa, omwe ndi njira yosinthira kuyamwa kolimbikitsidwa.
Pambuyo pa chiphunzitsocho, ndi chophweka kwambiri kupanga laser, monga momwe tawonetsera pamwambapa: pansi pazikhalidwe za kukhazikika kwa zinthu, ma electron ambiri ali pansi, ma elekitironi pansi, ndipo laser amadalira. kulimbikitsa ma radiation. Choncho, mapangidwe a laser ndi kulola kuti mayamwidwe osonkhezera ayambe kuchitika, kubweretsa ma elekitironi ku mlingo wapamwamba wa mphamvu, ndiyeno kupereka chisangalalo chochititsa kuti ma elekitironi ambiri apite patsogolo, kumasula ma photons, Kuchokera apa, laser ikhoza kupangidwa. Kenako, tikuwonetsa mawonekedwe a laser.
Laser kapangidwe:
Fananizani kapangidwe ka laser ndi mibadwo ya laser yomwe tatchula kale imodzi ndi imodzi:
Mkhalidwe wa zochitika ndi kapangidwe kofananira:
1. Pali sing'anga yopindulitsa yomwe imapereka mphamvu yokulitsa ngati sing'anga yogwira ntchito ya laser, ndipo tinthu tating'onoting'ono tomwe timakhala ndi mphamvu yopangira mphamvu yopangira ma radiation (makamaka amatha kupopera ma elekitironi kupita ku orbitals yamphamvu kwambiri ndipo imakhalapo kwa nthawi yayitali. , ndiyeno kumasula ma photon mu mpweya umodzi kupyolera mu cheza chokondoweza);
2. Pali gwero lachisangalalo lakunja (gwero la mpope) lomwe limatha kupopa ma elekitironi kuchokera kumunsi kumtunda kupita kumtunda, zomwe zimapangitsa kuti tinthu tating'onoting'ono tidutse pakati pa milingo yapamwamba ndi yotsika ya laser (ie, pakakhala tinthu tambiri tambiri tambiri kuposa tinthu tating'ono ting'onoting'ono tomwe timatulutsa mphamvu zambiri kuposa momwe timakhalira. particles otsika mphamvu), monga nyali xenon mu YAG lasers;
3. Pali phokoso la resonant lomwe lingathe kukwaniritsa laser oscillation, kuonjezera kutalika kwa ntchito ya laser yogwira ntchito, kuyang'ana mawonekedwe a mawonekedwe a kuwala, kuwongolera njira yofalitsa mtengo, kukulitsa mafupipafupi okhudzidwa ndi ma radiation kuti apititse patsogolo monochromaticity (kuwonetsetsa kuti laser imatulutsidwa ndi mphamvu inayake).
Kapangidwe kofananirako kakuwonetsedwa pachithunzi pamwambapa, chomwe ndi chosavuta cha YAG laser. Zomangamanga zina zitha kukhala zovuta kwambiri, koma maziko ake ndi awa. Njira yopangira laser ikuwonetsedwa pachithunzichi:
Gulu la laser: nthawi zambiri limagawidwa ndikupeza sing'anga kapena mawonekedwe amphamvu a laser
Pezani magulu apakati:
Carbon dioxide laser: The kupeza sing'anga carbon dioxide laser ndi helium ndiCO2 laser,yokhala ndi kutalika kwa laser kwa 10.6um, yomwe ndi imodzi mwazinthu zakale kwambiri za laser kuti zikhazikitsidwe. Kuwotcherera koyambirira kwa laser kunali makamaka zochokera ku carbon dioxide laser, yomwe panopa imagwiritsidwa ntchito kwambiri pakuwotcherera ndi kudula zinthu zopanda zitsulo (nsalu, mapulasitiki, nkhuni, etc.). Kuphatikiza apo, imagwiritsidwanso ntchito pamakina a lithography. Mpweya wa carbon dioxide laser sungathe kufalikira kudzera mu ulusi wa kuwala ndikuyenda kudutsa njira zowoneka bwino, Tongkuai oyambirira anachitika bwino, ndipo zida zambiri zodulira zidagwiritsidwa ntchito;
LAG (yttrium aluminium garnet) laser: Makhiristo a YAG okhala ndi neodymium (Nd) kapena yttrium (Yb) ma ion zitsulo amagwiritsidwa ntchito ngati njira yopezera laser, yokhala ndi kutalika kwa 1.06um. Laser ya YAG imatha kutulutsa ma pulse apamwamba, koma mphamvu yapakati ndi yotsika, ndipo mphamvu yapamwamba imatha kufika nthawi 15 mphamvu yapakati. Ngati makamaka ndi laser pulse, kutulutsa kosalekeza sikungakwaniritsidwe; Koma imatha kupatsirana kudzera mu ulusi wa kuwala, ndipo nthawi yomweyo, kuchuluka kwa mayamwidwe azinthu zachitsulo kumawonjezeka, ndipo kumayamba kugwiritsidwa ntchito pazinthu zowonetsera kwambiri, zoyamba kugwiritsidwa ntchito m'munda wa 3C;
Fiber laser: Zomwe zilipo pamsika zimagwiritsa ntchito ytterbium doped fiber ngati njira yopezera phindu, yokhala ndi kutalika kwa 1060nm. Imagawidwanso mu fiber ndi disc lasers kutengera mawonekedwe a sing'anga; Fiber optic imayimira IPG, pomwe chimbale chimayimira Tongkuai.
Laser ya semiconductor: Sing'anga yopindula ndi semiconductor PN mp3, ndipo kutalika kwa laser semiconductor kumakhala makamaka pa 976nm. Pakadali pano, ma semiconductor apafupi ndi infrared lasers amagwiritsidwa ntchito kwambiri povala, okhala ndi mawanga opepuka pamwamba pa 600um. Laserline ndi bizinesi yoyimira ma semiconductor lasers.
Zodziwika ndi mawonekedwe a mphamvu: Pulse laser (PULSE), quasi continuous laser (QCW), laser continuous (CW)
Pulse laser: nanosecond, picosecond, femtosecond, laser yothamanga kwambiri iyi (ns, pulse wide) imatha kukwaniritsa mphamvu zapamwamba kwambiri, ma frequency apamwamba (MHZ) processing, omwe amagwiritsidwa ntchito pokonza zamkuwa woonda ndi aluminiyamu zosiyana, komanso kuyeretsa nthawi zambiri. . Pogwiritsa ntchito mphamvu yapamwamba kwambiri, imatha kusungunula zinthu zoyambira, ndi nthawi yochepa yochitapo kanthu komanso malo ochepa omwe akhudzidwa ndi kutentha. Ili ndi ubwino pokonza zipangizo zowonda kwambiri (pansi pa 0.5mm);
Quasi continuous laser (QCW): Chifukwa cha kuchuluka kwa kubwereza komanso kutsika kwa ntchito (pansi pa 50%),laser QCWkufika 50 us-50 ms, kudzaza kusiyana pakati pa kilowatt mlingo mosalekeza CHIKWANGWANI laser ndi Q-switched kugunda laser; Pachimake mphamvu ya quasi mosalekeza CHIKWANGWANI laser akhoza kufika nthawi 10 mphamvu pafupifupi pansi mosalekeza mode ntchito. Ma lasers a QCW nthawi zambiri amakhala ndi mitundu iwiri, imodzi ndi kuwotcherera mosalekeza ndi mphamvu yochepa, ndipo inayo ndi kuwotcherera kwa laser yokhala ndi mphamvu yayikulu nthawi 10 kuposa mphamvu yapakati, yomwe imatha kukwaniritsa zida zokulirapo komanso kuwotcherera kutentha, komanso kuwongolera kutentha mkati mwa mtundu waung'ono kwambiri;
Continuous Laser (CW): Awa ndi omwe amagwiritsidwa ntchito kwambiri, ndipo ma lasers ambiri omwe amawonedwa pamsika ndi ma CW lasers omwe mosalekeza amatulutsa laser pakuwotcherera. Ma lasers a Fiber amagawidwa kukhala ma single-mode-mode-mode-mode-mode lasers molingana ndi mainchesi osiyanasiyana apakati ndi mikhalidwe ya mtengo, ndipo amatha kusinthidwa kuti akhale ndi mawonekedwe osiyanasiyana ogwiritsira ntchito.
Nthawi yotumiza: Dec-20-2023
