InGaAsP/InP双异质结发光管频响特性的研究

STUDY OF THE MODULATION FREQUENCY CHARACTERISTICS FOR THE InGaAsP/InP DH LED'S

本文研究了光纤通信用1.3μm InGaAsP/InP双异质结发光管的频响特性。结果表明:器件有源区掺杂浓度;有源层厚度;注入电流;光谱特性;P-n结特性等因素,对发光管的频响特性有重要影响。老化前有源区DSD的存在与否对频响无明显关系。

InGaAsP/InP edge-emitting LED's are capable of high coupling efficiency, winder tandwidth and narrower spectral halfwidth. In this paper,the characteristics of InGaAsP/InP edge-emitting LED's are described. The four-layer InGaAsP/InP DH wafers used for fabrication of the EELED's were grown by LPE technique. They are a 4-5μm n-type Inp buffer layer, an un-doped InGaAsP/InP active layer whose thickness varies from 0.2μm to 0.8μm; a p-InP confining layer and a Zn-doped cap layer,respectively. The position of p-n junction and concentration profile of wafers.The InGaAsP/InP edge-emitting LED's have been fabricated.The output power of the devices is about lmW(at 100mA),the emitting wavelength A is 1.3μm and the spectral halfwidth is about 860A. The dependence of characteristics of devices on material property has been investigated. The output power (P) increases as the active layer thickness(d)decreases.But the concentration of acceptor of the active layer changing from 4×1017cm-3 to 1×1018cm-3 has no effect on the output power of the devices. The far-field patterns in plane perpendicular to the junction exhibit asymmetry and its shape is changed with the excited current.When the p-n junction is in the active layer of wafers,the devices have a normal I-V characteristic,higher output power and a emitting peak of the wavelength 1.3μm,When the p-n junction is misplaced and departed from the active layer,the devices have an anomalous I-V characteristic,two emitting peaks of wavelength at 0.9μm and 1.3μm and lower output power. This characteristic is similar to the InGaAsP/InP surface-emitting LED's.