Umgaqo Wokwenza I-Laser

Kutheni kufuneka sazi umgaqo we-laser?

Ukwazi umahluko phakathi kweeleser ze-semiconductor eziqhelekileyo, iifayibha, iidiski, kunyeIleyiza ye-YAGinokunceda ekuqondeni ngcono nasekubandakanyeni kwiingxoxo ezingakumbi ngexesha lenkqubo yokukhetha.

Eli nqaku ligxile kakhulu kwisayensi ethandwayo: intshayelelo emfutshane kumgaqo wokwenziwa kwe-laser, ulwakhiwo oluphambili lwee-laser, kunye neentlobo ezahlukeneyo ze-laser eziqhelekileyo.

Okokuqala, umgaqo wokuveliswa kwe-laser

I-laser iveliswa ngokusebenzisana phakathi kokukhanya nezinto, okwaziwa ngokuba kukukhulisa imisebe okushukunyiswayo; Ukuqonda ukukhulisa imisebe okushukunyiswayo kufuna ukuqonda iingcamango zika-Einstein zokukhupha okuzenzekelayo, ukufunxwa okushukunyiswayo, kunye nokukhushulwa kwemisebe, kunye nezinye iziseko eziyimfuneko zethiyori.

Isiseko sethiyori 1: Imodeli yeBohr

Imodeli yeBohr ikakhulu inika ulwakhiwo lwangaphakathi lweeathom, okwenza kube lula ukuqonda indlela ezenzeka ngayo iilaser. Iathom yenziwe yinucleus kunye neee-electron ezingaphandle kwenucleus, kwaye ii-orbitals zeee-electron azixhomekekanga. Ii-electron zine-orbitals ezithile kuphela, apho i-orbital engaphakathi ibizwa ngokuba yimeko yomhlaba; Ukuba i-electron ikwimeko yomhlaba, amandla ayo aphantsi. Ukuba i-electron itsiba iphuma kwi-orbit, ibizwa ngokuba yimeko yokuqala yovuyo, kwaye amandla emeko yokuqala yovuyo aya kuba phezulu kunemeko yomhlaba; Enye i-orbit ibizwa ngokuba yimeko yesibini yovuyo;

Isizathu sokuba i-laser inokwenzeka kukuba ii-electron ziya kuhamba ngeendlela ezahlukeneyo kule modeli. Ukuba ii-electron zifunxa amandla, zinokubaleka ukusuka kwimeko yomhlaba ukuya kwimeko yovuyo; Ukuba i-electron ibuya kwimeko yovuyo ukuya kwimeko yomhlaba, iya kukhupha amandla, adla ngokukhululwa ngendlela ye-laser.

Isiseko sethiyori 2: Ithiyori ka-Einstein yokuVuselelwa kweMisebe

Ngo-1917, uEinstein wacebisa ithiyori yemitha evuselelweyo, eyisiseko sethiyori se-laser kunye nemveliso ye-laser: ukufunxwa okanye ukukhutshwa kwezinto ngokuyintloko sisiphumo sokusebenzisana phakathi kwentsimi yemitha kunye namasuntswana enza izinto, kwaye umongo wayo oyintloko kukutshintsha kwamasuntswana phakathi kwamanqanaba ahlukeneyo amandla. Kukho iinkqubo ezintathu ezahlukeneyo kunxibelelwano phakathi kokukhanya kunye nezinto: ukukhutshwa okuzenzekelayo, ukukhutshwa okuvuselelweyo, kunye nokufunxwa okuvuselelweyo. Kwinkqubo equlethe inani elikhulu lamasuntswana, ezi nkqubo zintathu zihlala zikho kwaye zinxulumene ngokusondeleyo.

Ukukhupha izinto ezikhutshwayo ngokuzenzekela:

Njengoko kubonisiwe kumfanekiso: i-electron ekwinqanaba eliphezulu lamandla i-E2 itshintshela ngokuzenzekelayo kwinqanaba eliphantsi lamandla i-E1 ize ikhuphe i-photon enegunya le-hv, kunye ne-hv=E2-E1; Le nkqubo yotshintsho oluzenzekelayo nolungadibaniyo ibizwa ngokuba yi-spontaneous transitions, kwaye amaza okukhanya akhutshwa zii-spontaneous transitions abizwa ngokuba yi-spontaneous radiation.

Iimpawu zokukhutshwa kwe-spontaneous: I-photon nganye izimele, ineendlela ezahlukeneyo kunye nezigaba, kwaye ixesha lokwenzeka kwayo nalo alicwangciswanga. Yeyokukhanya okungahambelaniyo nokungahambelaniyo, okungekuko ukukhanya okufunekayo yi-laser. Ke ngoko, inkqubo yokuveliswa kwe-laser kufuneka inciphise olu hlobo lokukhanya okungafunekiyo. Esi sisizathu sokuba ubude be-wavelength yee-laser ezahlukeneyo bube nokukhanya okungafunekiyo. Ukuba ilawulwa kakuhle, umlinganiselo wokukhutshwa kwe-spontaneous kwi-laser unokungahoywa. Okukhona i-laser icocekile, njenge-1060 nm, yonke yi-1060 nm, Olu hlobo lwe-laser lunezinga lokufunxa elizinzileyo kunye namandla.

Ukufunxwa okukhuthazwayo:

Ii-elektroni ezikwizinga eliphantsi lamandla (ii-orbital eziphantsi), emva kokufunxa ii-photon, zitshintshela kumanqanaba aphezulu wamandla (ii-orbital eziphezulu), kwaye le nkqubo ibizwa ngokuba yi-stimulated absorption. I-stimulated absorption ibalulekile kwaye yenye yeenkqubo eziphambili zokupompa. Umthombo wepompo ye-laser ubonelela ngamandla e-photon ukubangela amasuntswana kwi-gain medium ukuya kwi-transition kwaye alinde i-radiation evuselelweyo kumanqanaba aphezulu wamandla, ikhuphe i-laser.

Imitha evuselelweyo:

Xa ikhanyiswe kukukhanya kwamandla angaphandle (hv=E2-E1), i-electron ekwinqanaba eliphezulu lamandla iyavuselelwa yi-photon yangaphandle ize itsibe iye kwinqanaba lamandla aphantsi (umjikelezo ophezulu ubaleka uye kwi-orbit ephantsi). Kwangaxeshanye, ikhupha i-photon efana nqwa ne-photon yangaphandle. Le nkqubo ayifunxi ukukhanya kokuqala kokuvuselela, ngoko ke kuya kubakho ii-photon ezimbini ezifanayo, ezinokuqondwa njengoko i-electron ikhupha i-photon eyayifunxwe ngaphambili. Le nkqubo yokukhanya ibizwa ngokuba yi-radiation evuselelweyo, eyinkqubo echaseneyo yokufunxwa okuvuselelweyo.

Emva kokuba ithiyori icacile, kulula kakhulu ukwakha i-laser, njengoko kubonisiwe kumfanekiso ongentla: phantsi kweemeko eziqhelekileyo zokuzinza kwezinto, uninzi lwee-electron zikwimeko yomhlaba, ii-electron zikwimeko yomhlaba, kwaye i-laser ixhomekeke kwimitha evuselelweyo. Ke ngoko, ulwakhiwo lwe-laser kukuvumela ukufunxwa okuvuselelweyo ukuba kwenzeke kuqala, kuzise ii-electron kwinqanaba eliphezulu lamandla, kuze emva koko kunike uvuyo olubangela inani elikhulu lee-electron eziphezulu zamandla ukuba zidlule kwimitha evuselelweyo, zikhuphe ii-photon. Ukusuka koku, i-laser inokuveliswa. Okulandelayo, siza kwazisa ulwakhiwo lwe-laser.

Ulwakhiwo lwelaser:

Tshatisa ulwakhiwo lwelaser neemeko zokuveliswa kwelaser ezikhankanyiweyo ngaphambili nganye nganye:

Imeko yokwenzeka kunye nolwakhiwo oluhambelanayo:

1. Kukho i-gain medium enika isiphumo sokukhulisa njenge-laser esebenzayo, kwaye amasuntswana ayo asebenzayo anesakhiwo samandla esifanelekileyo sokwenza i-radiation evuselelweyo (ngokuyintloko ekwaziyo ukupompa ii-electron kwii-orbital ezinamandla aphezulu kwaye zihlale ixesha elithile, zize zikhuphe ii-photons ngokuphefumla kube kanye nge-radiation evuselelweyo);

2. Kukho umthombo wangaphandle wokuvuselela (umthombo wepompo) onokumpompa ii-electron ukusuka kwinqanaba elisezantsi ukuya kwinqanaba eliphezulu, nto leyo ebangela ukuguqulwa kwenani lamasuntswana phakathi kwamanqanaba aphezulu nasezantsi elaser (oko kukuthi, xa kukho amasuntswana anamandla aphezulu kunamasuntswana anamandla aphantsi), njengesibane se-xenon kwi-laser ze-YAG;

3. Kukho umngxuma ojikelezayo onokufikelela kwi-laser oscillation, wonyuse ubude bokusebenza kwezinto zokusebenza ze-laser, ukhusele imo ye-light wave, ulawule indlela yokusasazeka komqadi, unyuse ngokukhetha i-radiation frequency evuselelweyo ukuphucula i-monochromaticity (ukuqinisekisa ukuba i-laser ikhutshwa ngamandla athile).

Isakhiwo esihambelanayo siboniswe kumfanekiso ongentla, oluyisakhiwo esilula selaser ye-YAG. Ezinye izakhiwo zinokuba nzima ngakumbi, kodwa eyona nto iphambili yile. Inkqubo yokuveliswa kwelaser iboniswe kumfanekiso:

Ulwahlulo lweLaser: ngokubanzi luhlelwa ngokwe-gain medium okanye ngokwe-laser energy form

Udidi oluphakathi lokufumana inzuzo:

Ileyiza yekhabhoni diokside: I-gain medium ye-carbon dioxide laser yi-helium kunyeI-laser ye-CO2,nge-laser wavelength ye-10.6um, enye yeemveliso ze-laser zokuqala ukuqaliswa. I-laser welding yokuqala yayisekelwe kakhulu kwi-carbon dioxide laser, okwangoku esetyenziselwa kakhulu ukuwelda nokusika izinto ezingezizo zesinyithi (amalaphu, iiplastiki, umthi, njl.njl.). Ukongeza, ikwasetyenziswa nakwiimashini ze-lithography. I-carbon dioxide laser ayinakudluliselwa ngeefayibha ze-optical kwaye ihamba ngeendlela ze-spatial optical, iTongkuai yokuqala yenziwe kakuhle, kwaye kwasetyenziswa izixhobo ezininzi zokusika;

Ilaser ye-YAG (yttrium aluminium garnet): Iikristale ze-YAG ezifakwe i-neodymium (Nd) okanye i-yttrium (Yb) metal ions zisetyenziswa njenge-laser gain medium, enobude be-emission obuyi-1.06um. Ilaser ye-YAG inokukhupha ii-pulses eziphezulu, kodwa amandla aphakathi aphantsi, kwaye amandla aphezulu anokufikelela amaxesha ali-15 kumandla aphakathi. Ukuba ikakhulu yi-pulse laser, ukuphuma okuqhubekayo akunakufezekiswa; Kodwa inokudluliselwa ngeefayibha ze-optical, kwaye kwangaxeshanye, izinga lokufunxwa kwezinto zesinyithi liyakhula, kwaye iqala ukusetyenziswa kwizinto ezibonakalayo eziphezulu, ezisetyenziswa okokuqala kwintsimi ye-3C;

I-laser yefayibha: Eyona nto iphambili kwimarike isebenzisa i-ytterbium doped fiber njenge-gain medium, enobude obuyi-1060nm. Yahlulwe ngakumbi yaba yi-fiber kunye ne-disc lasers ngokusekelwe kwimilo ye-medium; I-Fiber optic imele i-IPG, ngelixa i-disc imele iTongkuai.

I-laser ye-semiconductor: I-gain medium yi-semiconductor PN junction, kwaye ubude be-laser ye-semiconductor bukwi-976nm. Okwangoku, ii-laser ze-semiconductor near-infrared zisetyenziselwa kakhulu ukugquma, kunye namabala okukhanya angaphezu kwe-600um. I-Laserline lishishini elimele ii-laser ze-semiconductor.

Ihlulwe ngohlobo lwentshukumo yamandla: I-Pulse laser (PULSE), i-quasi continuous laser (QCW), i-continuous laser (CW)

I-laser ye-pulse: i-nanosecond, i-picosecond, i-femtosecond, le laser ye-pulse ephindaphindayo (ns, ububanzi be-pulse) idla ngokufikelela kumandla aphezulu, ukucubungula i-frequency ephezulu (MHZ), isetyenziselwa ukucubungula izinto ezahlukeneyo ze-copper kunye ne-aluminium, kunye nokucoca uninzi. Ngokusebenzisa amandla aphezulu, inokunyibilikisa ngokukhawuleza izinto ezisisiseko, ngexesha elincinci lokusebenza kunye nendawo encinci echaphazelekileyo kubushushu. Inezibonelelo ekucubunguleni izinto ezincinci kakhulu (ngaphantsi kwe-0.5mm);

I-Quasi continuous laser (QCW): Ngenxa yesantya esiphezulu sokuphindaphinda kunye nomjikelo ophantsi womsebenzi (ngaphantsi kwama-50%), ububanzi be-pulseIleyiza ye-QCWifikelela kwi-50 us-50 ms, igcwalisa umsantsa phakathi kwe-kilowatt level continuous fiber laser kunye ne-Q-switched pulse laser; Amandla aphezulu e-quasi continuous fiber laser anokufikelela kwi-avareji ephindwe kalishumi xa esebenza kwi-continuous mode. Ii-QCW lasers zihlala zineendlela ezimbini, enye yi-continuous welding kumandla aphantsi, kwaye enye yi-pulsed laser welding enamandla aphezulu aphindwe kalishumi kumandla aphakathi, anokufikelela kwizixhobo ezityebileyo kunye ne-heat welding engaphezulu, ngelixa elawula ubushushu ngaphakathi koluhlu oluncinci kakhulu;

I-Laser eqhubekayo (CW): Le yeyona isetyenziswa kakhulu, kwaye uninzi lwee-laser ezibonakala kwimarike zii-laser ze-CW ezikhupha i-laser rhoqo ukuze kusetyenzwe nge-welding. Ii-laser zefayibha zahlulwe zibe zii-laser ze-single-mode kunye nee-multi-mode ngokweedayamitha ezahlukeneyo ze-core kunye neempawu ze-beam, kwaye zinokuhlengahlengiswa kwiimeko ezahlukeneyo zokusetyenziswa.