The Tektronix P6721 is an optical to electrical converter for 400 to 1000 nm wavelengths.
Rise time is 10 nanoseconds in standard version. The standard optical input connector is TOSLINK, output is BNC.
The P6721 consumes power, typically provided by an 1101A power supply. Conversion gain is 10 V/mW at 660 nm.
The P6721 uses a silicon PIN photodiode.