MITSUBISHI

MITSUBISHI LASER DIODESML9XX1 SERIESFOR OPTICAL COMMUNICATIONSAMPLE CHARACTERISTICSI Light output vs. forward currentTypical light output vs. forward current characteristicsare shown in Fig. 1. The threshold current forlasing is typically 15mA at room temperature.Above. the threshold, the light output increaseslinearly with current, and no kinks are observed in,the curves. An optical power of about 5mW isobtained at Ith + 25mA.As can be seen in Fig. 1. Ith and slope efficiencyT/ (dPo / dlF) depends on case temperature,obtaining a constant output at varying temperaturesrequires to control the case temperature Tc or thelaser current. (Control the case temperature or lasercurrent such that the output current of the builtinmonitor PO becomes constant.)I 4~SCo 3S0.E 2.2'...JFig. 1 Light output vS. forward current6r---'-~rr~r-r7--'----'Forward current IF (mA)II Temperature dependence of threshold current (lth).operating current (lop) and slope efficiency ( T/ )A typical temperature dependence of the thresholdcurrent and operating current (5mW) is shown inFig. 2. The characteristic temperature To. of thethreshold current is typically 65k in Tc => 40"C, 50kin Tc > 40 "C.Fig. 2 Temperature dependence of thresholdcurrent and operating currentI I-lop(5:nW\ ~