Detector for a fiber optic gyroscope
You will need a photodiode as the detector element.

You will also need a transimpedance amplifier circuit is to use it. 10Hz sample rate is nothing for optics. But sample rate is perhaps not as important as bandwidth.

But 1MHz is easy to achieve:
1 MHz, Single-Supply, Photodiode Amplifier Reference
Design

If you end up needing a logarithmic output then you need more circuitry.

You say sample, but that is not the same as bandwidth. It is unclear what you actually mean. Are you going to be displaying this signal on an oscilloscope or what?

Do note that laser diodes produce coherent BUT uncollimated light. I don't know enough about fiber optic gyros to know what type of light you need to inject but do not expect a parallel beam (or even a circular beam unless it is a VCSEL laser diode) from a laser diode without optics.