On the sensitivity of interactive damping of scanning near-field optical microscope probe

The effects of interactive damping on the sensitivity of flexural and axial vibration modes of a scanning near-field optical microscope are analyzed and a closed-form expression is derived. Through an exhaustive search, when the lateral spring constant is low, it was found that there are five important effects, i.e. (1) each mode has a different level of sensitivity and the optical fiber probe is the most acceptive to higher levels of flexural vibration in the first mode, (2) the probe is generally more sensitive when spring constant is lower, (3) the flexural sensitivities of the first five modes are similar when the lateral damping is taken into account, (4) the damping effect is proportional to the value of lateral spring constant, (5) the axial sensitivities of the first five-modes are analogously when the axial damping is taken into account.