Particularly high efficiencies are achieved with laser diodes emitting e. The efficiency of a diode laser is calculated using the formula: [ eta = left ( frac {P_ {out}} {P_ {in}} right) times 100% ] where: (P_ {in}) is the input power in watts (W). 5 watts of laser light (. EQE gauges the total conversion efficiency from all the injected electrons brought by the current to coherent output photons. But, a portion of the current is used in pumping the gain medium. for pumping ytterbium-doped high-power fiber devices), whereas 808-nm diodes are somewhat less efficient. As industrial, telecommunications, and research applications demand increasingly powerful and energy-efficient light sources, understanding the relationship between. The laser diode rate equations model the electrical and optical performance of a laser diode.