A circuit breaker comprising: a light source for emitting light; an optical sensor for detecting light emitted by the light source; a handle movable between different handle positions which correspond to different circuit breaker statuses, the handle including a handle body and a light control plate which moves along with the handle body, the light control plate having different light passage regions (210A-C, 610A-C, 710A-C) 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 (210A-C, 610A-C, 710A-C) allowing a different amount of light emitted from the light source to pass to the optical sensor when positioned between the light source and the optical sensor; and a processor configured to determine a status of the circuit breaker based on the sensed amount of light which relates to a position of the handle, wherein the light control plate extends from the handle body, the circuit breaker further comprising: an interior wall having opposing sides and a guide channel extending through the opposing first and second sides, the light control plate having a portion extending through the guide channel from the first side of the wall facing the handle body and being movable along the guide channel with movement of the handle, the optical sensor and the light source being connected on opposite sides of the guide channel on the second side of the wall; and a case for housing circuit breaker components including the interior wall. a light source for emitting light; an optical sensor for detecting light emitted by the light source; a handle movable between different handle positions which correspond to different circuit breaker statuses, the handle including a handle body and a light control plate which moves along with the handle body, the light control plate having different light passage regions (210A-C, 610A-C, 710A-C) 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 (210A-C, 610A-C, 710A-C) allowing a different amount of light emitted from the light source to pass to the optical sensor when positioned between the light source and the optical sensor; and a processor configured to determine a status of the circuit breaker based on the sensed amount of light which relates to a position of the handle, wherein the light control plate extends from the handle body, the circuit breaker further comprising: an interior wall having opposing sides and a guide channel extending through the opposing first and second sides, the light control plate having a portion extending through the guide channel from the first side of the wall facing the handle body and being movable along the guide channel with movement of the handle, the optical sensor and the light source being connected on opposite sides of the guide channel on the second side of the wall; and a case for housing circuit breaker components including the interior wall. an interior wall having opposing sides and a guide channel extending through the opposing first and second sides, the light control plate having a portion extending through the guide channel from the first side of the wall facing the handle body and being movable along the guide channel with movement of the handle, the optical sensor and the light source being connected on opposite sides of the guide channel on the second side of the wall; and a case for housing circuit breaker components including the interior wall.