A dual fiberoptic detector with a built-in microscope allows the two arms of a wideband coupler or a multiplexer to be measured simultaneously. It offers reproducibility of 0.02 dB and measures attenuation as high as 40 dB over the 900- to 1700-nm range. Clamps fix the fiber reproducibly, and the microscope produces a 50x image. A 2-mm-diameter InGaAs detector measures the light, and a shutter prevents hysteresis effects caused by exposure to room light during fiber insertion.
Reading, Berkshire, England