LD-PD’s photodetectors contain PIN photodiodes that utilize the photovoltaic effect to convert optical power into an electrical current. When terminated into 50Ω into an oscilloscope, the pulse width of a laser can be measured. When terminated into 50Ω into a spectrum analyzer, the frequency response of a laser can be measured. Most LD-PD's photodetectors come with their own internal bias supply consisting of long-life lithium cells. Plugging a coaxial cable into the photodetector's output connector and terminating into 50Ω at the oscilloscope or spectrum analyzer is all that is required for operation.
The APD modules enable very low light levels to be detected quickly and simply in a variety of applications such as laser radar, rangefinding, dat...