After a lot of research, I chose a NUBM44 6W 450nm solid state laser. I was debating whether to use lower powered lasers that could produce a finer beam, but I wanted to try the higher power in case it could cut thicker materials or work at faster speeds. So far, I am happy with the choice. I am getting an engraved line that is 0.5mm wide in wood. That is fine enough for the work I envision doing with it.
I purchased the laser, driver, and heatsink all as a package. The driver has two wires for the power supply, and it has an on/off control line, but there was no wire provided. I would have to solder a wire to the driver board, which is inaccessible since the board was bonded inside of the heatsink. If I were to do it again, I would order the driver separately or ask to have a lead added for the control line.
My workaround was to connect a 12 vdc relay between the power supply and the laser driver. I wired the coil to the 12 vdc supply and Output 1 of the G540, pin 5 of the breakout. The switch contacts of the relay control the 12 vdc supply to the laser driver. I’m using M62 and M65 to switch the laser on/off in the g-code.
Here’s a video of my first project with the laser.