• A review of demodulation techniques for amplitude-modulation atomic force microscopy 

      Ruppert, Michael G.; Harcombe, David M.; Ragazzon, Michael Remo Palmén; Moheimani, S.O. Reza; Fleming, Andrew J. (Journal article; Peer reviewed, 2017)
      In this review paper, traditional and novel demodulation methods applicable to amplitude-modulation atomic force microscopy are implemented on a widely used digital processing system. As a crucial bandwidth-limiting component ...
    • Frequency domain analysis of robust demodulators for high-speed atomic force microscopy 

      Ruppert, Michael G.; Harcombe, David M.; Ragazzon, Michael Remo Palmén; Moheimani, S.O. Reza; Fleming, Andrew J. (Journal article; Peer reviewed, 2017)
      A fundamental but often overlooked component in the z-axis feedback loop of the atomic force microscope (AFM) operated in dynamic mode is the demodulator. Its purpose is to obtain a preferably fast and low-noise estimate ...
    • Generalized Lyapunov Demodulator for Amplitude and Phase Estimation by the Internal Model Principle 

      Ragazzon, Michael Remo Palmén; Messineo, Saverio; Gravdahl, Jan Tommy; Harcombe, David M.; Ruppert, Michael G. (Journal article; Peer reviewed, 2019)
      Effective demodulation of amplitude and phase is a requirement in a wide array of applications. Recent efforts have increased the demodulation performance, in particular, the Lyapunov demodulator allows bandwidths up to ...
    • Higher-Harmonic AFM Imaging with a High-Bandwidth Multifrequency Lyapunov Filter 

      Harcombe, David M.; Ruppert, Michael G.; Ragazzon, Michael Remo Palmén; Fleming, Andrew J. (Journal article; Peer reviewed, 2017)
      A major difficulty in multifrequency atomic force microscopy (MF-AFM) is the accurate estimation of amplitude and phase at multiple frequencies for both z-axis feedback and material contrast imaging. A lock-in amplifier ...
    • Lyapunov estimation for high-speed demodulation in multifrequency atomic force microscopy 

      Harcombe, David M.; Ruppert, Michael G.; Ragazzon, Michael Remo Palmén; Fleming, Andrew J. (Journal article; Peer reviewed, 2018)
      An important issue in the emerging field of multifrequency atomic force microscopy (MF-AFM) is the accurate and fast demodulation of the cantilever-tip deflection signal. As this signal consists of multiple frequency ...
    • Lyapunov Estimator for High-Speed Demodulation in Dynamic Mode Atomic Force Microscopy 

      Ragazzon, Michael Remo Palmén; Ruppert, Michael G.; Harcombe, David M.; Fleming, Andrew J.; Gravdahl, Jan Tommy (Journal article; Peer reviewed, 2017)
      In dynamic mode atomic force microscopy (AFM), the imaging bandwidth is governed by the slowest component in the open-loop chain consisting of the vertical actuator, cantilever, and demodulator. While the common demodulation ...