The Optical Choppers offered by Hinds Instruments are resonant devices designed to work at one frequency. We offer several ways to chop light: a High Speed Optical Chopper (HSOC), a Chopping System, and a Photoelastic Modulator (or PEM).

High Speed Optical Chopper

The HSOC is calibrated for one wavelength, from 180nm – 1 µm. However, it can be used within a +/- 10% range from the center wavelength without a change in calibration. The frequencies to choose from are 40, 50, and 60 kHz. The HSOC comes in a small, single enclosure package. All optics and drive electronics are included.

Chopper System

The Chopping System is also calibrated for one wavelength but those wavelengths range from 130nm – 18µm. As with the HSOC, it can be used within a +/- 10% range from the center wavelength. This model allows the user to choose a chopper frequency within the range 20 kHz to 84 kHz and consists of an optical unit and separate control electronics.

Photoelastic Modulator

The PEM is the most versatile choice. The wavelength range can be from 130nm – 18µm depending on the model of optical head chosen and the PEM can be used for non-chopping applications in separate set ups. Its operation as a chopper over large wavelength ranges requires additional optics (one linear and one circular polarizer) to convert the PEM into a chopper system. These can be obtained from Hinds Instruments or purchased separately by the user. The basic PEM comes in three modules: the optical head, the drive electronics and the control electronics. Frequencies range from 20-84 kHz.

All Hinds chopper options offer:

  • Wide acceptance angle
  • No moving parts
  • Minimal heat generation
  • No safety concerns
  • Small footprint and lightweight
  • Quiet operation
  • Low power consumption
  • Meets CE and RoHS compliance regulations

 

Selecting Your Optical Chopper

 High Speed
Optical Chopper

Chopper

System

PEM
50 kHz Operation * * *
Other Frequencies   * *
Wavelength Adjustable     *
Demodulation Electronics Available * * *
Software Available for Computer Control * * *
Configured for >10 mW/cm2   * *
Configured for < 10 mW/cm2 * * *
Smallest Footprint *    
Lowest Cost *