Products incorporating these laser diodes will normally be classified as CLASS IV laser products according to IEC 60825-1 in a normal operation mode. Direct exposure of the human eye with laser radiation is therefore hazardous and must be strictly avoided. This optical damage can happen even with a momentary over-current. They may be built into larger arrays, e. : 3 Driven by voltage, the doped. Semiconductor lasers are solid-state lasers based on semiconductor gain media, where optical amplification is usually achieved by stimulated emission at an interband transition under conditions of a high carrier density in the conduction band.