Mfundo Yopangira Laser

N’chifukwa chiyani tiyenera kudziwa mfundo ya lasers?

Kudziwa kusiyana pakati pa ma lasers, ulusi, ma disc, ndi ma semiconductor lasers wambalaser ya YAGZingathandizenso kumvetsetsa bwino ndikukhala ndi zokambirana zambiri panthawi yosankha.

Nkhaniyi ikuyang'ana kwambiri pa sayansi yotchuka: chiyambi chachidule cha mfundo yopanga laser, kapangidwe kake ka laser, ndi mitundu ingapo yodziwika bwino ya laser.

Choyamba, mfundo yopanga laser

Laser imapangidwa kudzera mu mgwirizano pakati pa kuwala ndi zinthu, zomwe zimadziwika kuti stimulated radiation amplification; Kumvetsetsa stimulated radiation amplification kumafuna kumvetsetsa malingaliro a Einstein okhudza kutulutsa kwadzidzidzi, kuyamwa kwamphamvu, ndi kuwala kolimbikitsidwa, komanso maziko ena ofunikira a chiphunzitso.

Maziko a Chiphunzitso 1: Chitsanzo cha Bohr

Chitsanzo cha Bohr chimapereka kapangidwe ka mkati mwa maatomu, zomwe zimapangitsa kuti zikhale zosavuta kumvetsetsa momwe ma laser amachitikira. Atomu imapangidwa ndi nucleus ndi ma electron kunja kwa nucleus, ndipo ma orbitals a ma electron si okhazikika. Ma electron ali ndi ma orbitals enaake okha, omwe orbital yamkati imatchedwa ground state; Ngati electron ili mu ground state, mphamvu yake ndi yotsika kwambiri. Ngati electron idumpha kuchokera mu orbit, imatchedwa started state yoyamba, ndipo mphamvu ya started state yoyamba idzakhala yayikulu kuposa ya ground state; orbit ina imatchedwa second excited state;

Chifukwa chomwe laser ingachitikire ndichakuti ma elekitironi amasuntha m'njira zosiyanasiyana mu chitsanzo ichi. Ngati ma elekitironi amatenga mphamvu, amatha kuthamanga kuchokera ku ground state kupita ku excited state; Ngati elekitironi ibwerera kuchokera ku excited state kupita ku ground state, imatulutsa mphamvu, yomwe nthawi zambiri imatulutsidwa ngati laser.

Maziko a Chiphunzitso 2: Chiphunzitso cha Einstein Cholimbikitsa Kutulutsa Ma Radiation

Mu 1917, Einstein adapereka lingaliro la kuwala kolimbikitsidwa, komwe ndi maziko a chiphunzitso cha ma laser ndi kupanga laser: kuyamwa kapena kutulutsa kwa zinthu kwenikweni kumachitika chifukwa cha kuyanjana pakati pa munda wa kuwala ndi tinthu tomwe timapanga zinthu, ndipo chinsinsi chake chachikulu ndi kusintha kwa tinthu pakati pa mphamvu zosiyanasiyana. Pali njira zitatu zosiyana pakuyanjana pakati pa kuwala ndi zinthu: kutulutsa kodzidzimutsa, kutulutsa kolimbikitsidwa, ndi kuyamwa kolimbikitsidwa. Pa dongosolo lomwe lili ndi tinthu tambirimbiri, njira zitatuzi nthawi zonse zimakhalapo ndipo zimagwirizana kwambiri.

Kutulutsa mpweya mwadzidzidzi:

Monga momwe chithunzichi chikusonyezera: elekitironi pa mlingo wa mphamvu zambiri E2 imasinthasintha yokha kupita ku mlingo wa mphamvu zochepa E1 ndipo imatulutsa photon yokhala ndi mphamvu ya hv, ndi hv=E2-E1; Njira yosinthira yodzidzimutsa komanso yosagwirizana iyi imatchedwa kusintha kwadzidzidzi, ndipo mafunde owala omwe amatuluka ndi kusintha kwadzidzidzi amatchedwa kuwala kwadzidzidzi.

Makhalidwe a kutulutsa kwadzidzidzi: Photon iliyonse ndi yodziyimira payokha, yokhala ndi mayendedwe ndi magawo osiyanasiyana, ndipo nthawi yochitika nayonso ndi yachisawawa. Ndi ya kuwala kosakhazikika komanso kosokonezeka, komwe si kuwala komwe laser imafuna. Chifukwa chake, njira yopangira laser iyenera kuchepetsa mtundu uwu wa kuwala kosadziwika. Ichi ndi chimodzi mwazifukwa zomwe kutalika kwa ma laser osiyanasiyana kumakhala ndi kuwala kosadziwika. Ngati ilamulidwa bwino, gawo la kutulutsa kwadzidzidzi mu laser linganyalanyazidwe. Laser ikayera kwambiri, monga 1060 nm, yonse ndi 1060 nm, Mtundu uwu wa laser uli ndi liwiro lokhazikika la kuyamwa ndi mphamvu.

Kuyamwa kolimbikitsidwa:

Ma electron omwe ali ndi mphamvu zochepa (zozungulira zochepa), atatha kuyamwa ma fotoni, amasamutsira ku mphamvu zapamwamba (zozungulira zapamwamba), ndipo njirayi imatchedwa kuyamwa kolimbikitsidwa. Kuyamwa kolimbikitsidwa ndikofunikira kwambiri ndipo ndi imodzi mwa njira zofunika kwambiri zopopera. Gwero la pampu ya laser limapereka mphamvu ya photon kuti ipangitse tinthu tating'onoting'ono mu gain medium kupita ku kusintha ndikudikirira kuwala kolimbikitsidwa pa mphamvu zapamwamba, kutulutsa laser.

Ma radiation oyambitsidwa:

Ikawotchedwa ndi kuwala kwa mphamvu yakunja (hv=E2-E1), elekitironi yomwe ili pamlingo wapamwamba wa mphamvu imasangalatsidwa ndi photon yakunja ndikudumphira kumlingo wotsika wa mphamvu (mzere wapamwamba umathamangira ku mzere wotsika). Nthawi yomweyo, imatulutsa photon yomwe ili yofanana ndi photon yakunja. Njirayi simatenga kuwala koyambirira koyambitsa, kotero padzakhala ma photon awiri ofanana, omwe angamveke pamene elekitironi imatulutsa photon yomwe idalowetsedwa kale. Njira yowunikira iyi imatchedwa stimulated radiation, yomwe ndi njira yotsutsana ndi stimulated absorption.

Pambuyo poti chiphunzitsocho chamveka bwino, ndikosavuta kupanga laser, monga momwe zasonyezedwera pachithunzi pamwambapa: pansi pa mikhalidwe yabwinobwino ya kukhazikika kwa zinthu, ma elekitironi ambiri amakhala mu mkhalidwe wa nthaka, ma elekitironi ali mu mkhalidwe wa nthaka, ndipo laser imadalira kuwala kolimbikitsidwa. Chifukwa chake, kapangidwe ka laser ndikulola kuyamwa kolimbikitsidwa kuchitika kaye, kubweretsa ma elekitironi pamlingo wapamwamba wa mphamvu, kenako kupereka chisangalalo chomwe chimapangitsa kuti ma elekitironi ambiri amphamvu kwambiri adutse mu kuwala kolimbikitsidwa, kutulutsa ma photon. Kuchokera apa, laser ikhoza kupangidwa. Kenako, tikuwonetsa kapangidwe ka laser.

Kapangidwe ka laser:

Gwirizanitsani kapangidwe ka laser ndi mikhalidwe yopanga laser yomwe yatchulidwa kale imodzi ndi imodzi:

Mkhalidwe wa zochitika ndi kapangidwe kofanana:

1. Pali njira yopezera mphamvu yomwe imapereka mphamvu yowonjezera mphamvu monga njira yogwirira ntchito ya laser, ndipo tinthu take tomwe timayatsidwa tili ndi kapangidwe ka mphamvu koyenera kupanga mphamvu yosonkhezera (makamaka yomwe imatha kupopera ma elekitironi kupita ku ma orbital amphamvu kwambiri ndikukhalapo kwa nthawi inayake, kenako nkutulutsa ma photoni mu mpweya umodzi kudzera mu mphamvu yosonkhezera);

2. Pali gwero lakunja losonkhezera (gwero la pampu) lomwe limatha kupompa ma elekitironi kuchokera pamlingo wotsika kupita pamlingo wapamwamba, zomwe zimapangitsa kuti tinthu tating'onoting'ono tisinthe pakati pa milingo yapamwamba ndi yotsika ya laser (mwachitsanzo, pamene pali tinthu tating'onoting'ono tochuluka kuposa tinthu tating'onoting'ono tochepa), monga nyali ya xenon mu ma laser a YAG;

3. Pali malo ozungulira omwe amatha kupangitsa kuti laser izungulire, kuwonjezera kutalika kwa ntchito ya laser, kuwunikira mawonekedwe a mafunde a kuwala, kuwongolera njira yofalitsira kuwala, ndikuwonjezera mwachangu ma radiation frequency kuti akonze monochromaticity (kuonetsetsa kuti laser imatulutsa mphamvu inayake).

Kapangidwe kofananako kakuwonetsedwa pachithunzi pamwambapa, chomwe ndi kapangidwe kosavuta ka laser ya YAG. Kapangidwe kena kangakhale kovuta kwambiri, koma pakati pake ndi ichi. Njira yopangira laser ikuwonetsedwa pachithunzichi:

Kugawa kwa laser: nthawi zambiri kumagawidwa malinga ndi njira yopezera mphamvu kapena mawonekedwe a mphamvu ya laser

Gulu lapakati la phindu:

Laser ya kaboni dioxide: Gain medium ya laser ya carbon dioxide ndi helium ndilaser ya CO2,ndi kutalika kwa laser kwa 10.6um, komwe ndi chimodzi mwa zinthu zoyambirira za laser zomwe zinayambitsidwa. Kuwotcherera koyambirira kwa laser kunkachokera makamaka ku laser ya carbon dioxide, yomwe pakadali pano imagwiritsidwa ntchito kwambiri powotcherera ndi kudula zinthu zosakhala zachitsulo (nsalu, pulasitiki, matabwa, ndi zina zotero). Kuphatikiza apo, imagwiritsidwanso ntchito pamakina a lithography. Laser ya carbon dioxide singathe kufalikira kudzera mu ulusi wa kuwala ndipo imayenda m'njira zowunikira zamlengalenga, Tongkuai yoyambirira idapangidwa bwino kwambiri, ndipo zida zambiri zodulira zidagwiritsidwa ntchito;

LAZA ya YAG (yttrium aluminum garnet): Makristalo a YAG okhala ndi ma ayoni achitsulo a neodymium (Nd) kapena yttrium (Yb) amagwiritsidwa ntchito ngati njira yopezera mphamvu ya laser, yokhala ndi kutalika kwa mphamvu yotulutsa ya 1.06um. LAZA ya YAG imatha kutulutsa mphamvu zambiri, koma mphamvu yapakati ndi yotsika, ndipo mphamvu yayikulu imatha kufika nthawi 15 kuposa mphamvu yapakati. Ngati ndi laser ya pulse makamaka, mphamvu yopitilira singatheke; Koma imatha kufalikira kudzera mu ulusi wa kuwala, ndipo nthawi yomweyo, kuchuluka kwa kuyamwa kwa zinthu zachitsulo kumawonjezeka, ndipo ikuyamba kugwiritsidwa ntchito pazinthu zowunikira kwambiri, zomwe zimagwiritsidwa ntchito koyamba m'munda wa 3C;

Laser ya fiber: Kampani yomwe imagwiritsa ntchito magetsi a ytterbium monga njira yopezera mphamvu, yokhala ndi kutalika kwa 1060nm. Imagawidwanso m'ma laser a fiber ndi disc kutengera mawonekedwe a chipangizocho; Fiber optic imayimira IPG, pomwe disc imayimira Tongkuai.

Laser ya semiconductor: Gain medium ndi semiconductor PN junction, ndipo kutalika kwa mafunde a laser ya semiconductor kuli pa 976nm. Pakadali pano, ma semiconductor near-infrared lasers amagwiritsidwa ntchito makamaka pophimba, ndi malo owala pamwamba pa 600um. Laserline ndi kampani yoyimira ma semiconductor lasers.

Yogawidwa motsatira mawonekedwe a mphamvu: Pulse laser (PULSE), quasi continuous laser (QCW), continuous laser (CW)

Laser ya pulse: nanosecond, picosecond, femtosecond, laser ya pulse ya frequency yapamwamba (ns, pulse width) nthawi zambiri imatha kupeza mphamvu yayikulu, kukonza ma frequency apamwamba (MHZ), imagwiritsidwa ntchito pokonza zinthu zosiyanasiyana za mkuwa woonda ndi aluminiyamu, komanso kuyeretsa kwambiri. Pogwiritsa ntchito mphamvu yayikulu, imatha kusungunula zinthu zoyambira mwachangu, ndi nthawi yochepa yogwira ntchito komanso malo ochepa omwe amakhudzidwa ndi kutentha. Ili ndi ubwino pokonza zinthu zoonda kwambiri (pansi pa 0.5mm);

Quasi continuous laser (QCW): Chifukwa cha kuchuluka kwa kubwerezabwereza komanso kutsika kwa ntchito (pansi pa 50%), m'lifupi mwa kugunda kwa mtimaLaza ya QCWimafika 50 us-50 ms, kudzaza kusiyana pakati pa kilowatt level continuous fiber laser ndi Q-switched pulse laser; Mphamvu yayikulu ya quasi continuous fiber laser imatha kufika kuwirikiza ka 10 mphamvu yapakati pa ntchito yopitilira. Ma laser a QCW nthawi zambiri amakhala ndi njira ziwiri, imodzi ndi yopitira patsogolo pa mphamvu yochepa, ndipo inayo ndi yopitira patsogolo ya laser yokhala ndi mphamvu yayikulu yowirikiza ka 10 mphamvu yapakati, yomwe imatha kukwaniritsa zinthu zokhuthala komanso yotenthetsera kwambiri kutentha, komanso kuwongolera kutentha mkati mwa mtunda wochepa kwambiri;

Laser Yosalekeza (CW): Iyi ndi yomwe imagwiritsidwa ntchito kwambiri, ndipo ma laser ambiri omwe amapezeka pamsika ndi ma laser a CW omwe nthawi zonse amatulutsa laser yogwiritsira ntchito kuwotcherera. Ma laser a fiber amagawidwa m'ma laser amtundu umodzi ndi mitundu yambiri malinga ndi kukula kwa ma core diameter osiyanasiyana ndi mawonekedwe a beam, ndipo amatha kusinthidwa malinga ndi zochitika zosiyanasiyana zogwiritsidwa ntchito.