I set out to test the actuation bandwidth of the 950nm laser. I hooked the laser to the output of the bias tee of PD testing setup. I connected the fiber coming out of the laser to the fiber port of 1611 REF PD.

The current source was connected to the DB9 input of the PD testing setup. I turned on the current source and set the current to 20mA. I measured with a fluke ~ 2V at the REF PD DC port.

I connected the AC port of the bias tee to the RF source of the network analyzer and the AC port of the REF PD to the B port of the network analyzer. Attachment 2 shows the setup.

I took a swept sine measurement (attachment) from 100kHz to 500MHz.

It seems like the bandwidth is ~ 1MHz which is weird considering the spec sheet says that the pulse rise time is 0.5ns. To make sure we are not limited by the bandwidth of the cables I looped the source and the input of the network analyzer using the cables used for the previous measurement and observed that the bandwidth is a few 100s of MHz.