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Optical Chopper System, Phase Locked, Includes 4 Wheels
4 Weeks
4 Weeks


  • Type
    Phase Locked Optical Chopper
  • Chopper Wheel
    2, 5, 12 and 30 apertures
  • Chopping Frequency
    4 Hz to 2.0 kHz
  • Phase Shifter Range
    -180 deg to +179 deg
  • Harmonic Chopping
    2 to 15
  • Sub-Harmonic Chopping
    1/2 to 1/15
  • Dimensions
    Controller: 102 x 216 x 368 mm


Complete Chopper System for Spectroscopy Applications

The 75160NF comes complete four chopper wheels, an enclosed chopper head with Oriel mounting flange, and a chopper controller with USB 2.0 interface. All it require to run is connect power cable and its ready for chopping action.

Functional block diagram for Model 75160NF Optical Chopper System

Enclosed Chopper Head

The controller drives the chopper head containing a multi-aperture wheel to modulate the light. The chopper head includes Oriel 1.5-inch series flanges, which couple to a wide variety of Oriel instruments. Chopper wheels are easily interchangeable. The enclosed chopper head design prevents detector saturation from unchopped background light and prevents scattering. When chopping lasers or UV beam, you can reduce potential hazards by enclosing the beam path.  For replacement or stand alone ordering of this chopper head, contact your Newport sales representative for part number 75150-1050.

Dimensions of Oriel Optical Chopper Head

Four Broadband Absorber Coated Chopper Wheels Included

The 75160NF comes with four chopper wheels. Oriel chopper wheels are precision etched, and coated with a broadband absorber to minimize retroreflections. The chopping rate may be set from 4 Hz to 2.00 kHz depend on the chopper wheel. Replacement models are available.

Maximum beam diameter is dependent on wheel aperture size.

Advanced Optical Chopper Controller

The front panel display of the controller allows monitoring of the chopping frequency, as well as a number of other operating parameters. Easy-to-use cursor keys provide easy adjustment of operating parameters. The chopping rate may be set from 4 Hz to 2.00 kHz, using either the internal frequency synthesizer or an external source as the reference. Chopping mode options are selectable at the fundamental, a harmonic (2 to 15), or even a sub-harmonic (1/2 to 1/15) of the reference.

Stable and Reliable Phase Locking

For stable chopping with minimum jitter and drift, the chopper head uses precision photo-etched wheels mounted on a high-quality DC motor. In addition, the chopper controller has its own internal crystal-controlled frequency synthesizer and phase-locked loop for precisely locking the chopping frequency. A photo-interrupter on the chopper head monitors the chopping frequency, and the chopper controller actively stabilizes the motor speed to ensure stable chopping with a minimum of frequency drift.