  We utilize steady-state and transient optical spectroscopies to examine the
responses of nonthermal quasiparticles with respect to orbital modifications in
normal-state iron-chalcogenide superconductors. The dynamics shows the
emergence of gap-like quasiparticles (associated to a ~36 meV energy gap) with
a coincident transfer of the optical spectral weight in the visible range, at
temperatures above the structural distortion. Our observations suggest that
opening of the high-temperature gap and the lattice symmetry breaking are
possibly driven by short-range orbital and/or charge orders, implicating a
close correlation between electronic nematicity and precursor order in
iron-based superconductors.
