The present invention provides a transmitting circuit that improves the SN ratio in a higher output power and the CN ratio in an intermediate to lower output power, and makes linear the characteristic of the attenuation gain. The data storage device includes a data storage medium and second device. Even in case of negative voltage, a circuit can be configured on the same principle as the positive voltage. The light transmittance enhancement layer is made of silicon dioxide or magnesium fluoride. In another embodiment, a single-edged blade featuring two cutting faces is housed in a knife handle. The upper electrode layer and the dielectric layer are sequentially patterned.