I will be building a single color projector on a tight budget for a senior project and writing the software for it from scratch. It looks like I will be using a laser with TTL modulation. What kind of modulation does the correction amp use?
The Audiolase DAC, if thats the one you meant is both analog and ttl. If the software you use to control it is set to analog then the voltage on the mod channels will be 0 to 5V with more intensity to the beam the closer to 5 you get. If the software is set to TTL then it should deliver 0V in off state and 5V in on state. Some lasers with TTL will be on when the voltage exceeds a given threshold, not always 5V.
Some LAB lasers and diy drivers have inverted TTL. Meaning that they are on at 0V and off at 5V. It is possible to "invert" the TTL signal in the software you use to control it.
EDIT: It should be the exact same for the LaserBoy solution.