Hi all,
In my opinion power penalty can’t be negative because :
1. you say it the power required to compensate losses in the fiber link or any other parameter in the system due to which the loss is caused.
2. there is no logic to apply negative power. To my understanding it must always be positive because the theory suggests so But yeah i can’t be sure shot here.
Opinions and logics do vary.
Anyways, thanks and regards