Ngokuvamile, ukushuba kwemisebe ye-laser yi-Gaussian, futhi ngesikhathi sokusebenzisa i-laser, isistimu ye-optical ngokuvamile isetshenziselwa ukuguqula i-beam ngokufanele.

Ihlukile kumbono womugqa we-geometric optics, i-optical transformation theory ye-Gaussian beam ayiyona i-linear, ehlobene eduze nemingcele ye-laser beam ngokwayo kanye nokuma okuhlobene kwesistimu yokubona.

Kunamapharamitha amaningi ukuchaza i-Gaussian laser beam, kodwa ubudlelwano phakathi kwerediyasi yendawo kanye nokuma kokhalo lwe-beam kuvame ukusetshenziswa ekuxazululeni izinkinga ezingokoqobo. Okusho ukuthi, i-radius okhalweni lwe-beam yesigameko (ω₁) kanye nebanga lesistimu yokuguqula i-optical (z₁) zaziwa, bese kuba irediyasi okhalweni oluguquliwe (ω₂), ukuma kwe-beam okhalweni (z₂) kanye ne-radius yendawo (ω₃) kunoma yisiphi isikhundla (z) ziyatholakala. Gxila ku-lens, bese ukhetha izindawo ezingaphambili nezingemuva ze-lens njengendiza yereferensi 1 kanye nendiza yereferensi 2 ngokulandelanayo, njengoba kuboniswe ku-Fig.

                     Umdwebo 1 Ukuguqulwa kwe-Gauss ngokusebenzisa ilensi encane

Ngokusho kwepharamitha q inkolelo-mbono ye-Gaussian beam, i q₁ futhi q₂ ezindizeni ezimbili eziyisithenjwa zingavezwa kanje:

Kule fomula engenhla: The f_e1 futhi f_e2 ngokulandelana amapharamitha we-confocus ngaphambi nangemuva koguquko lwe-Gaussian beam. Ngemuva kokuthi ugongolo lwe-Gaussian ludlula endaweni yamahhala z₁, ilensi encane enobude bokugxila F kanye nendawo yamahhala z₂, ngokusho kwe A B C D i-transmission matrix theory, okulandelayo kungatholakala:

Okwamanje, q₁ futhi q₂ ukwanelisa ubudlelwano obulandelayo:

Ngokuhlanganisa amafomula angenhla nokwenza izingxenye zangempela nezicatshangwayo kuzo zombili iziphetho zezibalo zilingane ngokulandelana, singathola:

Izibalo (4) – (6) ziwubudlelwane bokuguqulwa phakathi kwesimo sokhalo kanye nosayizi wendawo we-Gaussian beam ngemva kokudlula kulensi encane.