For the past ten years, NIST has used high-reflectivity, optical choppers as beamsplitters and attenuators when calibrating the absolute responsivity and response linearity of detectors used with high-power CW lasers. The chopper-based technique has several advantages over the use of wedged-shaped transparent materials (usually crystals) often used as beamsplitters in this type of measurement system. We describe the design, operation and calibration of these choppers. A comparison between choppers and transparent wedge beamsplitters is also discussed.
Citation: Journal of Research (NIST JRES) -
NIST Pub Series: Journal of Research (NIST JRES)
Pub Type: NIST Pubs
attenuator, high-power laser, infrared (IR), K-series calorimeter, laser beamsplitter, laser detector calibration, laser power meter, monitor detector, optical crystal, reflective optical chopper (ROC), ZnSe.