  Recent advancements in wavefront shaping techniques have facilitated the
study of complex structured light's propagation with orbital angular momentum
(OAM) within various media. The introduction of a spiral phase modulation to
the Laguerre-Gaussian (LG) beam during its paraxial propagation is facilitated
by the negative gradient of the medium's refractive index's temporal change,
resulting in an accelerated retardation in OAM twist. This approach attains
remarkable sensitivity to even the slightest variations in the medium's
refractive index (10^(-6)). The phase memory of OAM is revealed as the ability
of twisted light preserving initial helical phase even propagating through the
turbid tissue-like multiple scattering medium. The results confirm fascinating
opportunities of the exploiting OAM light in biomedical applications, e.g. such
as non-invasive trans-cutaneous glucose diagnosis and optical communication
through biological tissues and other optically dense media.
