650 Series Light Choppers


The 650 series of light choppers features a control box with separate chopping heads for remote operation.

Supplier: Signal Recovery


  • Quartz internal clock for more precision
  • Adjusting the frequency via chopper or via an external TTL (LockIn)
  • Synchronization TTL output

The new SIGNAL RECOVERY 650 modulator series has been specially designed for long time measurements requiring very high stability and minimum drift.

Designed around two elements:
> Control box with RS232 allowing to modify the working frequency of your modulator with 5 digits display
> Two discs and a motor in a closed housing that can be mounted on an optical table

The connection between these two elements is done by means of a cable of maximum 3 meters rolling up, which will allow you not to clutter your optical table.

The 650 series can be controlled manually (via control box) or by an external TTL/ CMOS signal coming from your synchronous detection.


  • Frequency from 4Hz to 5Khz with a resolution of 0.001Hz
  • Frequency Control: Phase Loop, DDS
  • Jitter phase: 0.1%
  • Synchronization output: TTL, CMOS
  • RS232 interface and ChopperVI.exe control software included

Product applications

  • Optical measurements