Fermi sea excitations in the optical spectrum of a doped 3He droplet

► A chromophore molecule in 3He droplet acts as a probe of the Fermi liquid excitations. ► Zero-phonon line is determined by the particle-hole excitations of the Fermi liquid. ► Low-energy excitations result in a strong asymmetry of the line and the gapless wing. ► A theoretical tool to investigate 3He dropletsvia spectroscopy of probe molecules.