you are welcome tanveer,
Well as far as i am concerned , you make your design power efficient if you somehow try to get better results at low power i mean better than results taken at optimum power level. For that you may vary different parameters like data rate , length of fiber and other parameters too. As of now i can think of varying such things to make the design power efficient.
Now regarding power dissipation, i don’t think you can measure it directly here. For that you must consider different losses relating to power.
Regards