A circuit breaker can include a light source, an optical sensor, a handle and a processor. The handle can be movable between different handle positions which correspond to different circuit breaker statuses. The handle can include a handle body and a light control plate which moves along with the handle body. The light control plate can have different light passage regions each of which is configured to be positioned between the light source and the optical sensor when the handle is moved to a corresponding one of the different handle positions. Each of the different light passage regions allows a different amount of light emitted from the light source to pass to the sensor when positioned between the light source and the sensor. The processor is configured to determine a status of the circuit breaker based on the sensed amount of light which relates to a position of the handle.