Constant Amplitude AFM
Applications: Scanning probe microscopy (SPM), atomic force microscopy (AFM), contact and non-contact modes, Kelvin probe force microscopy (KPFM)
Measurements in atomic force microscopy are moving towards higher cantilever frequencies, multi-frequency, and multi-mode operation. Applications that previously performed on lock-in amplification below 1 MHz are moving into the regions of tens of MHz. Scientists demand scanning at ever increasing speeds and thus require instrumentation with small time constants, in order to capture very fast events.
| Objectives: | performing lock-in amplification in a phase-locked loop at multiple cantilever modes simultaneously. |
| Benefits: | integrated solution for AFM oscillation control, including 2 lock-in amplifiers, 2 frequency generators, PLL functionality, a frequency response sweeper, and a programming environment to implement and execute custom control algorithms inside the measurement instrument (real-time control) - no need for additional costly real-time hardware |
| Relevant products: | HF2LI, HF2LI-RT, HF2LI-UHS, HF2LI-PID, HF2LI-PLL |
HF2PLL Constant Amplitude AFM Mode
Driving the cantilever with a constant amplitude can be achieved by adding a PID controller to the setup. The controller sets the generator's drive depending on the amplitude signal (R) of the demodulator. You can easily expand the capability of the base lock-in amplifier HF2LI with the PLL-option to enable amplitude controlled scanning in a phase locked loop.
Key Features of the HF2PLL Phase-locked Loop for this Application
- 3 instruments in 1: double lock-in amplifier, double frequency generator, frequency response sweeper
- 1 µHz to 50 MHz frequency range
- 2 independent lock-in units
- 6 simultaneous frequencies
- Real-time programmability
- Integrated oscilloscope
- Ultra-high stability option