gentleman and ladies that is what a bias voltage is all about. It moves zero up to the point that the laser starts emitting as a laser. Problem is it makes the laser an led/laser and makes a dot on the wall. This is why people like beam suppression that starts the beam at the bias voltage but when no signal is seen drops the bias to zero. Since diodes react so fast this works. This essentially compresses the modulation signal. What would be more appropriate would be to do the bias voltage and compress the 0-5v signal in to the lower range 1.28-5v or 3.72V. if you have 8 bits that is 0.0145V per step as apposed to the 0.0195V per step for the 5V modulation signal. Since you are rescaling the signal from 5v to 3.72v it makes no difference in pallet because the steps are made smaller when the signal is rescaled.
Nobody seems to do this though and just accepts the compression. The only device I know that does this the eyemagic iris system.
I envision simply using a voltage divider ie pot and then adding the bias voltage to the result would do the job fine without any active electronics. Could also be done with an opamp and act as a buffer at the same time. Negative gain opamps work same as gain opamps. That seems overly built though and I'd just do the passives.
