Dkngyen,
We had to do this for a laser diode for one of our senior student's Honors Projects. Constant-current source using a standard three-terminal voltage regulator with a switched shunt to chop the laser output. Attached is a schematic, scaled down to fit your current levels. High control turns the SSR ON, low turns it OFF. If you need the reverse, drop Q1, move R2 to between the base and emitter of Q2, and put R1 between your control input and the base of Q2. The component values are a "mind experiment" and not bench tested (we were using much higher currents), but they should be close enough to start.
Ken