Observer based imaging methods for Atomic Force Microscopy

In atomic force microscopy, bandwidth or resolution can be affected by active quality factor (Q) control. However, in existing methods the trade off between resolution and bandwidth remains inherent. Observer based Q control method provides greater flexibility in managing the tradeoff between resolution and bandwidth during imaging. It also facilitates theoretical analysis lacking in existing methods. Steady state signals like amplitude and phase are slowly varying variables that are suited to image low bandwidth content of the actual sample profile. Observer based transient imaging scheme with Q control has the promise of detecting high bandwidth content of the sample features during scanning. Transient detection also has the advantage of high sensitivity to small features.