Lock-in amplifiers can be equipped with amplitude and frequency modulation capabilities with the new AM/FM Modulation Option. This option enables coherent generation and detection of signals with multiple frequency components, such as amplitude- and frequency modulated signals. Up to three frequencies can be coherently combined to generate fully configurable AM signals. The three characteristic frequency components of arbitrary AM signals can also be simultaneously demodulated giving optimum signal recovery performance. FM signals can be generated and detected by the three demodulators, allowing the carrier frequency and sidebands to be measured simultaneously, even in the case of narrow sidebands. All the amplitude and phase components are individually acquired, each with adjustable filter settings. Likewise, for signal generation, each frequency component can be individually set in terms of phase relation, frequency and amplitude.
In contrast to conventional methods where two cascaded lock-ins are used for tandem demodulation, all Zurich Instruments Lock-in amplifiers can perform single-stage demodulation using the multiple demodulators available in each instrument. This overcomes the bandwidth limitation of cascaded demodulation filters and leads to more accurate results. The graphical LabOne user interface facilitates signal generation and acquisition, allowing simple adjustment of each component parameter. The integrated toolset reduces experiment complexity with a scope, sweeper, spectrum analyzer, signal generator, spectrogram, plotter and more.
The AM/FM Modulation Option is used in a variety of applications such as MEMS, Fluorescence Spectroscopy or Kelvin Probe Force Microscopy (KPFM) where AM/FM modulation and demodulation improves the SNR.
Zurich Instruments, Technoparkstrasse 1, CH-8005 Zurich ,www.zhinst.com