Incazelo evame ukusetshenziswa yekhwalithi ye-beam ihlanganisa irediyasi yendawo ekude, ukwehlukana kwenkundla ekude angle, umkhawulo we-diffraction multiple U, Strehl isilinganiso, isici M2 , vula amandla indawo eqondisiwe noma isilinganiso samandla esiluphu, njll.

Ikhwalithi ye-Beam iyipharamitha ebalulekile ye-laser. Izinkulumo ezimbili ezivamile zekhwalithi ye-beam yileziI-BPP futhi M2 okuyinto zisuselwa kumqondo ofanayo womzimba futhi zingaguqulwa komunye nomunye. Ikhwalithi ye-laser beam ibalulekile ngoba iyinani elibalulekile lomzimba ukwahlulela ukuthi i-laser yinhle noma cha nokuthi i ukucubungula ngokunemba kungenziwa. Ezinhlotsheni eziningi zamalaser aphuma ngemodi eyodwa, amalaser ekhwalithi ephezulu avamise ukuba nekhwalithi ephezulu kakhulu, ehambisana nencane kakhulu.M2, njengokuthi 1.05 noma 1.1. Ngaphezu kwalokho, i-laser ingagcina ikhwalithi enhle yomugqa kuyo yonke impilo yayo yenkonzo, futhiM2 inani licishe lingashintshiwe. Ngomshini wokunemba we-laser, ikhwalithi ephezuluugongolo ilungele ukubunjwa, ukuze kwenziwe umshini we-laser oyisicaba ngaphandle kokulimaza i-substrate futhi ngaphandle komphumela oshisayo. Empeleni,M2 isetshenziswa kakhulu kuma-laser aqinile negesi, ngenkathi I-BPP isetshenziswa kakhulu kuma-laser we-fiber lapho ilebula imininingwane yama-lasers.

Ikhwalithi ye-Laser beam ngokuvamile iboniswa ngamapharamitha amabili: I-BPP futhi M². M²ivame ukubhalwa ngokuthi M2. Umfanekiso olandelayo ubonisa ukusatshalaliswa kwe-longitudinal kwe-Gaussian beam, laphoW iyi-radius okhalweni lwe-beam futhi θ uhhafu wokuhlukana kwenkundla ekude angle.

Ukuguqulwa kwe-BPP kanye M2

I-BPP (Umkhiqizo we-Beam Parameter) ichazwa ngokuthi i-radius okhalweni W iphindaphindwe nge uhhafu wokuhlukana kwenkundla ekude angle θ:

         BPP = W × θ

I uhhafu wokuhlukana kwenkundla ekude angle θ I-Gaussian beam yile:

        θ₀ = λ / πW₀

M² isilinganiso somkhiqizo wepharamitha yomkhiqizo womkhiqizo wepharamitha yemodi eyisisekelo ye-Gaussian beam:

        M² =（W×θ）/（W₀×θ₀）= BPP /（λ / π）

Akunzima ukuthola kule fomula engenhla lokho I-BPP izimele ku-wavelength, ngenkathi M² futhi ayihlobene ne-laser wavelength. Ngokuyinhloko zihlobene nomklamo we-cavity kanye nokunemba komhlangano we-laser.

Inani le M² isondele kakhulu ku-1, okubonisa isilinganiso phakathi kwedatha yangempela nedatha efanelekile. Uma idatha yangempela iseduze nedatha efanelekile, ikhwalithi ye-beam iba ngcono, okungukuthi, niniM² iseduze no-1, i-engeli yokuhlukana ehambisanayo incane, futhi ikhwalithi ye-beam ingcono.

Isilinganiso weBPP kanye M2
Isihlaziyi sekhwalithi ye-Beam singasetshenziswa ukukala ikhwalithi ye-beam. Ikhwalithi ye-beam nayo ingakalwa kusetshenziswa i-analyzer yokukhanya nokusebenza okuyinkimbinkimbi. Idatha iqoqwa ezindaweni ezahlukene ze-laser cross section bese ihlanganiswa ngohlelo lokwakha ukuze kukhiqizwe.M2. M2 ayikwazi ukulinganiswa uma kukhona iphutha lokusebenzisa kabi noma ukulinganisa ohlelweni lokuthatha amasampula. Ukuze uthole izilinganiso zamandla aphezulu, isistimu yokunciphisa amandla eyinkimbinkimbi iyadingeka ukuze kugcinwe amandla e-laser ngaphakathi kwebanga elilinganisekayo futhi kugwenywe noma yikuphi ukulimala kwendawo yokuthola insimbi.

I-optical fibre core kanye nokuvuleka kwezinombolo kungalinganiselwa ngokuya ngesibalo esingenhla. Ngama-laser fiber, i-radius okhalweni ω₀= i-fiber core diameter /2 = R, θ = isonoα =α= NA (i-aperture yenombolo yefiber).

Isifinyezo se-BPP, M2, futhi Bem Qukuphila

I-BPP encane, ingcono ikhwalithi ye-laser beam.

Ngo-1.08µama-fiber lasers m, M2 = 1, I-BPP = λ / p = 0.344 mm Mnuisikhangiso

Kwa-10.6µm CO₂ ama-laser, imodi eyodwa eyisisekelo M2 = 1, I-BPP = 3.38 mm Mnuisikhangiso

Kucatshangwa ukuthi ama-engeli okuhlukana okukodwa okuyisisekelo imodi ama-laser (noma imodi eminingi lasers okufanayo M2) ziyefana ngemva kokugxila, ububanzi obugxile be-CO₂ i-laser iphindwe izikhathi ezingu-10 kune-fiber laser.

Okuseduze M2 ukuya ku-1, kungcono ikhwalithi ye-laser beam.

Lapho i-laser beam ingenile Gukusatshalaliswa kwe-aussian noma ukusabalalisa okuseduze kwe-Gaussian, i- M2 ku-1, lapho i-laser yangempela isondelana ne-laser ye-Gaussian efanelekile, iba ngcono ikhwalithi ye-beam.