Figure 25.4 — Near-resonant laser cooling Figure 25.4 — Near-resonant laser cooling. (a) Sketch illustrating the one-dimensional laser cooling configuration for a number of levitated nanosystems. Two counter-propagating laser beams interact with hybrid metal–quantum emitter nanoparticles, silica microparticles sustaining Mie resonances hybridised with plasmonic nanoparticles, or graphene flakes hybridised with a quantum emitter. The near-resonant excitation close to a Fano resonance is tuned by changing the incident light detuning (Ridolfo et al., 2011). (b) Normalised radiation pressure cross-sections for hybrid nanostructures with Fano lineshapes. The lineshape and Fano factor, q, change with the coupling within hybrid particles. The plots for a Lorentzian, |q| = ∞ (dash-dotted line), and two Fano lineshapes, q = 0.5 (dashed line) and q = −1.5 (solid line), are shown. MNP = metal nanoparticle, QE = quantum emitter, WGM = whispering gallery mode. ε is the detuning normalised to the line width, i.e., ε = 2δ/Γ.