Need help finding the right transistor for a switching circuit
You are likely to be better off using a MOSFET than a BJT.

We typically assume a BJT will have on the order of 0.2 V between collector and emitter in saturation. With 1 A collector current, that means 200 mW of power dissipation in the transistor.

MOSFET's drain-source channels on the other hand act a lot more like low-value resistors when fully switched.

Going to On Semi, I found several dozen available FETs with channel resistance (rDS(on)) below 50 milliohms for gate voltage of 4.5 V and current handling capability above 1.5 A. With this level of on resistance, the power dissipation is reduced to ~50 mW. 

Lower power dissipation means a smaller package, probably lower cost, more power available for other functions, and less worry about thermal problems with your laser.