What is the advantage of a fiber-coupled version versus a free-space detector or receiver?
The high-speed detector/receivers have a relatively small detector area, and the fiber is bonded to the detector so that all the input light is incident on the detector’s active area. The free-space detector requires the user to direct the light onto the detector’s active area (which may have a diameter of no more than 25 µm). Thus, there is a chance that not all the light will be incident on the active area. Overfilling the detector will produce a response although it will be weaker and slower due to the photogenerated charge carriers migrating to the active area through diffusion rather than drift. We do not offer free-space versions of our ultrahigh-speed detectors (>35 GHz), because these detectors are <12-µm in diameter, and illuminating (and finding) the active area can be a difficult and tedious task. The fiber-optic approach takes the guesswork out of finding the active area of the detectors. Moreover, we've designed the ultrahigh-speed photodetector modules to connect directly
