Pick two points on the linear part of the L-I curve and threshold current plus slope efficiency fall out — the quickest health check for a laser.
Above threshold, output power rises nearly linearly with current; the slope is the slope efficiency η, and extrapolating back to the current axis gives the threshold current Ith. The method assumes both points sit on the linear section: keep clear of the soft knee near threshold (spontaneous-emission transition) and of thermal rollover at high current where junction heating bends the curve. Points too close together amplify reading errors — span at least a third of the linear section.
Temperature moves the two parameters in opposite directions: as junction temperature rises, Ith grows as exp(T/T₀) (T₀ = characteristic temperature; larger is better) while η slowly falls — which is what full-temperature LIV testing is for. Factory reports provide full-curve fits; this page is for quick off-line checks.
Related tools: dBm↔mW · PD responsivity
※ Formulas on this page assume ideal models; all device parameters shown are typical values — refer to the datasheet and the serialized factory test report shipped with each unit. For selection support, contact sales@lncetek.com.