EOT's Amplified Photodetectors contain PIN photodiodes that utilize the photovoltaic effect to convert optical power into an electrical current and a fixed gain transimpedance amplifier allowing measurement of <1 mW input powers. 

When terminated into 50 Ω into an oscilloscope, the pulsewidth of a laser can be measured. When terminated into 50 Ω into a spectrum analyzer, the frequency response of a laser can be measured. 

EOT's Amplified Photodetectors come with their own wall plug-in power supply Plugging a coaxial cable into the photodetector's SMA or BNC output connector and terminating into 50 Ω at the oscilloscope or spectrum analyzer is all that is required for operation.

Amplified Photodetectors Data Sheet