= Lyubomir Stoyanov
{c}
\b[Lyubomir Stoyanov] is an optical researcher associated with the Department of Quantum Electronics at Sofia University. His author-hosted profile and publication list identify work on structured <laser> fields and their propagation.<Lyubomir Stoyanov academic profile and publications>[Personal Information and publication list]{ref} His coauthored work includes measurements of the <Gouy phase> of <Bessel-Gaussian beams> and higher-order <Hermite-Gaussian optical modes>.
A 2024 experiment used <spatial light modulator> preparation of higher-order <Hermite-Gaussian optical modes> and interferometry to compare their <Gouy phase> with the familiar mode-order prediction.<Experimental Verification of the Gouy Phase for Higher-Order Hermite-Gaussian Beams by Lyubomir Stoyanov and others>[p.1138, Abstract, mode preparation, interferometric measurement and comparison]{ref} Measuring the phase supplies information that a beam's spot pattern alone cannot provide.
For an original ideal-mode example, define the positive Gouy-phase function by
$$
\psi_{mn}(z)=(m+n+1)\arctan(z/z_R),
$$
where $z_R>0$ is the <Rayleigh range>. In a field convention containing $e^{i(kz-\omega t)}$, this factor contributes $e^{-i\psi_{mn}}$. Thus the $(m,n)=(2,0)$ mode at $z=z_R$ has $\psi_{20}=3\pi/4$, three times the fundamental mode's $\pi/4$. The formula states a convention explicitly so that the sign of the additional field phase is not confused with the sign of the named positive function.
Comparing modes at matched $z/z_R$ is important. A change of focusing geometry can change the <Rayleigh range>, while the mode-order factor changes the phase at a fixed normalized distance. An interferometric comparison therefore needs both mode identification and calibrated propagation position. These ideal numbers illustrate the model; they are not fitted results from the paper.
\Image[https://loop.frontiersin.org/images/profile/2514975/203]
{title=Lyubomir Stoyanov; portrait linked by his Frontiers Loop profile identifying Sofia University}
{height=300}
Back to article page
