I am working on making a Laser Line break system for a squash court, to alert the referee if the ball breaks the beam (out of play line) . I am using a 5mw laser diode and set up a LDR to receive the light. The system is working but the LDR is way too slow to react to the ball breaking the beam. I need something faster, possibly a phototransistor, or photodiode. Does anyone have any experience with these, and an idea at what would be better to use, it also needs to be relatively cheap, as i have seen a lot ranging from $1 to over $100! I don't want to have to buy twenty different units to test if i can help it.
Both photo transistor or diode should be usable. A transistor is a tiny bit slower, but provides a higher signal.