A new signal format that allows sharing of spectrum with CDMA signals with a minimum amount of mutual interference and a maximum amount of processing gain. In one embodiment, an offset digital-to-analog converter provides a first programmable bias corresponding to an offset of the amplifier circuit. According to the method, powers within a domain of the plurality of test powers are considered until a considered power is selected as the target power for the optical disk. 01 to 10 wt %; and a second sub-composition including a glass additive composed of a B2O3, a ZnO, a SiO2 and at least one of a CuO, a CaCO3 and a BaCO3, wherein the glass additive has a weight ranged from 5 to 40 wt %.