Think on this 3 purple photonic science doffs offer 60 percent reduction in cool down time for Photonic officer abilities, add the deflector that reduces science cool downs by 10 percent. That's 70 percent reduced cool down. Photonic Officer II according to the sto wiki reduces all bridge officer timers by 32 percent and Photonic Officer II is a bridge officer ability. That 102 percent cooldown reduction of Photonic Officer. Photonic Officer II offers a 32 percent reduction in cooldowns for tac and eng power for 60 seconds and with the fleet deflector it becomes 42 percent reduced cooldowns for other sci powers.
Cannon rapid fire for example would effectively be reduced almost forever from 30 seconds to 20.8 seconds.