Anfatec Instruments AG
Measurement Science and Technology &
Scanning Probe Microscopy

Basic Version of a digital SPM controller with one lockin amplifier


  • DS4 Module: versatile SPM controller for the automated approach
    • 8 channels @ 24 Bit D/A and 8 channel @ 24 Bit A/D
    • control of three stepper motors for the coarse approach
    For the coarse approach, we provide many additional options: slip stick movements, steppers in x- and y-direction, ... 
  • Gaming fun with Joystick 3D Control

Each controller includes:

  • a controller in compact module housing (for example: DS4L) or 19” rack housing
  • modern dual-processor PC in Anfatec's PC design with TFT monitor
  • PCI-card AMU with SXM-DSP for data exchange between PC and controller & lockin amplifier
  • an open source software under Windows 2000 / XP, which supplies all basic functions for any SPM application but is also suitable for other applications.
  • power supply for the DS4 module
  • handbook in English

A/D channels (SMB connectors):

  • input voltages:            -10 V...+10 V
  • resolution(nominally):  24 Bit
  • resolution(@ 160 kHz): 16 Bit
  • integrated adapted anti-aliasing filter
  • only 2 µs latency

D/A channels (SMB connectors):

  • output voltages:           -10 V...+10 V
  • resolution(nominally):   24 Bit
  • spectral noise density:  100 nV/Hz1/2 @ 100 Hz

Digital Inputs and Outputs:

  • up to 4 adaptable for costumer specific funtions

Motor Driver:

  • power supply:            12 V dc
  • power consumption    0.3 A per motor


Properties possible due to the software:

  • simultaneous acquisition of almost unlimited number of pictures (limitation starts for example at 20 pictures with 512 pixel due to the PC)
  • integrated distance control (IP controller) with over 6 different feedback modes
  • slope correction during scan
  • free parameter input during scan
  • 4 different types of spectroscopy (any signal vs. distance, any signal vs voltage, ...)
  • computer controlled coarse positioning and automated approach
  • adapable to almost all hardware due to
    • free scalabity of all channels in physical units
    • offset correction for each hardware channel
    • sign inversion possible
    • relation between hardware channel and name is open
  • additional adjustment for user specific setups:
    • number of steps for stepper motor approach,
    • delays and repeat times for slip stick controls

Optional features:


Controller Versions (examples)

SICM and SECM
These methods used by chemists and biologists need an easy to handle software for the acquisition of vibration spectra and the selection of suitable resonances. Anfatec has developed a simplified version of it's controller for this application. A resonance history allows to compare spectra with different parameters. Not used software parts can be disabled for easier handling.
Home-Built SNOM or IR-SNOM based on PI-scan-tables
The free scalability of the channels allows to limit the output voltages for the scan tables to -2 V ... 10 V, as needed by scan tables from Physics Instruments. Based on those tables and the closed loop PI-piezo controller, Anfatec has provided several SPM controlling units for home built SNOM systems. The mechanical realization has been mainly developed by costumers, however, Anfatec is an open cooperation partner, and supplies mechanically adapted photodetectors as well as specialized mechanical solutions.
Combination of Attocube scanner and translation stages in home-built UHV-AFM
Attocube scan and positioning tables are a perfect solution for UHV applications. Anfatec's controller is able to control these tables directly from the internal software. During the high-resolution image acquisition, the switching power supplies needed for voltage generation are switched off.
Replacement for outdated Park Universal AFM's
Park Scientific Instruments has formerly built a series of instruments, which is of extraordinary mechanical stability. One might keep this mechanical construction and replace the outdated controller with a proved solution from Anfatec, which has been developed in cooperation with the FZ Karlsruhe.
Replacement for UHV-AFM/STM systems
One of the implemented feedback modes in Anfatec's controller is a vacuum-AFM feedback (comparable with the Easy-PLL, but without self-excitation). Controlling amplitude, phase shift and distance simultaneously in three different feedback circuits is a challenge. Anfatec has a suitable and costumer friendly solution for it. Especially, when a vacuum-AFM should be combined with electrical measurements, Anfatec's controller is the most affordable replacement for broken controllers. This controller comes in two units for 19” rack mounting. A recently developed unit for 800 V slip-stick controls allows to control for example Omicron's translators with 1 ms pulses in a very efficient and comfortable way.

Besides these applications, we use it in our Level-AFM. Therefore, it's features are constantly growing.

   HOPG taken with a DS4 module and a W-tip in air