A laptop that interacts with a television system. The respective optical path lengths of main and auxiliary optical paths differ from each other between the first and second optical couplers and between the second and third optical couplers. The anionite in the nitrate form is used as an anionite, and its regeneration is performed in an aqueous solution of alkali or alkali-earth metal nitrate at the temperature of 0-60\xb0 C.