Upconversion Nanoparticle Physics: Power Law & Depth Attenuation

This is the 2D counterpart to the 3D upconversion nanoparticle imaging scene, computing the same lanthanide-doped Yb³⁺/Er³⁺ energy-transfer upconversion rate-balance model through four analytic views instead of a rendered nanocrystal cluster: a tissue cross-section showing the NIR pump beam attenuate with depth into a glowing nanocrystal cluster, a log-log power-law curve exposing the signature slide from a two-photon slope n≈2 down to a saturated n≈1, a depth-attenuation chart comparing how far green and red upconverted light survive escaping tissue, and a live sensitizer/activator population diagram. Tune the pump power, wavelength (980 vs 808 nm), Yb:Er doping ratio and tissue depth and watch every readout and every plot react to the same formulas.