A mirror used for a laser beam, said mirror includes a substrate, an aluminum layer formed on the substrate, a dielectric layer formed on the aluminum layer, and an aluminum oxide layer provided between the aluminum layer and the dielectric layer, wherein said aluminum oxide layer has an optical thickness nd of 3. Given a first and second OLED, the first electrode is connected to a first terminal of the first OLED, the second electrode is connected to a second terminal of the first OLED and to a first terminal of the second OLED, and the third electrode is connected to a second terminal of the second OLED. The variable-volume lens includes a lens film, an accommodation space wrapped by the lens film, and a transparent fluid within the accommodation space. Active control of the operating point of the fuel cell allows for optimized power output and fuel cell efficiency. Iodine values of 10 or less down to 1 and 0.