I am using a function generator to generate a sine input to a modulated laser. The function generator has output settings of 50 Ω and High-Z, while the laser for some reason has a 1 kΩ input impedance. What would be the best way to connect these to modulate the laser as close to the input signal as possible? When just connecting both and looking at the laser output I am seeing fluctuations (which may or may not be due to the mismatch).
Is an impedance matching circuit required? Will a simple hand-soldered L-pad of just resistors do the job? Maximum frequency is around 50 kHz.
Bonus question: Why does the laser have 1 kΩ input impedance? Why not any other value, specifically why not 50 Ω or some large value like 1 or 10 MΩ?
The datasheet of the laser can be found here (DPL laser, analog modulation, page 14. Ignore the maximum frequency, that's a typo).