Fig. 3. Evolution of CDW phases in 1T-TaS₂ induced by mid-infrared pulses at 25 K.

(A) Optically induced evolution of CDW states characterized by CDW suppression (in ratio, based on unperturbed CDW intensity) and CDW angle Φ at various absorbed photon density at a base temperature T_B of 25 K using the 800-nm pump photons. The inset shows the diffraction images of the unpumped (ground state) and excited CDW at the quasi-equilibrium time, +20 ps. The central Bragg peak is masked out to highlight the changes in CDW intensity. (B to D) Angular profiles of the CDW peak at selected pump optical density n_λ. At n_λ = 2.6 nm⁻³, the CDW is in a mixed state between NC* and IC. The fit shows the individual components of the IC (dashed gray) and NC* (dashed red) to compose the best fit of the mixed state (solid red), whereas the green curve represents an attempted fit by using the C and IC as the constituent states.