Yes, the ones on the right are the same point and the output from your op amp. The other is just a test point so you can see where the waveform and where it switches.
But I don't think it will work because the voltage drop across the 1k will be to large driving into the 50 ohm load.
A better solution might be to use a switch like a DG2039 to open the signal from your op amp to the laser. I guess I was confused by
We can set the trip point closer to zero, but you will always loose to low counts using this method.
I'm also concerned about your statement that the DAC voltage dropped when hooked to the driver, but maybe that is ok.
Is there any other signal available that says the DAC is at 0?