TOSA中pin背光探测器的P-I非线性特性研究

Study of P-I Nonlinear Response of pin Back Light Detectors In TOSA

TOSA中用到的pin背光探测器是监测与控制LD前光输出特性的敏感器件,其光功率(P)和光电流(I)应具有线性关系。测试发现,不同结构和尺寸的探测器的P-I特性可能有所不同。目前普遍使用的正面进光的pin平面型光探测器,常存在某种范围的P-I非线性。分析指出,这种非线性与器件内部结构、表面接触层情况、入射光密度、外加负偏压大小和负载电阻有关;并指出,当pin-PD中pi结位置合适、外加负偏压1.5 V以上,负载电阻1 kW,LD前光入射光功率8 mW以下,则pin背光探测器的P-I非线性可忽略。

The pin back light detector used in TOSA is the sensitive device for monitoring and controlling the LD's front output light power.The light power(P) from the back of LD should have the linear relationship with its photoelectric current(I).The tests show that the P-I characteristic of the detector with the different structures and sizes may be different.Some kinds of P-I nonlinear of the plane light detector were reported.It is pointed out that this kind of P-I nonlinear is concerned with the internal structure of devices,superficial contact layer situation,incident light density,negative bias voltages and load resistance.It is indicated that the P-I nonlinear of pin detector may be neglected,when the poison of pi junction in pin-PD is suitable,the negative bias voltage is larger than 1.5 V,the light power from the front of LD is lower than 8 mW and the road resistance of pin-PD is lower than 1 kSymbolWA@.