GaAlAs快速边发光管发射端面沉积Al2O3抗反射层的研究

本文报导了在快速DH GsAs-GaAlAs边发光管发射端面上溅射沉积Al2O3抗反射层的研究,涂层厚度与输出光功率的提高密切相关,层厚接近λ/4值时,在200mA下光功率输出的提高达~80%.

INVESTIGATION OF A12O3 ANTIREFLECTIVE COATING FOR GaAlAs HIGH SPEED LEDs

In this paper the effect of antireflective coating (ARC) on the emitting facet on the light power output of edge emitting diode is reported.In high speed GaAs/GaAlAs DH-LEDs with sputtered A12O3 as AR coating on the front emitting facet, a remarkable increase in light power output has been achieved. The fabricated LEDs have two types of structure:normal edge emitter and edge emitter with optical waveguide structure.A conventional rf sputtering equipment with the source power of 3kW at 13.5 MC was used in preparing the A12O3 AR coating (refractive index 1.65~1.7). A high purity A12O3 disk was employed as a target.Before sputtering the high-purity Ar gas was further purified by passing it through molecular sieve 5A and hot Ti coils.The light power output of a normal edge emitter as a function of current density is plotted in Fig.3.At a driving current density of 4kA/cm2, the light power increases from 370nW for the uncoated LED to 495uW for the same diode coated with~1890Å A12O3.This corresponds to a light-power increase of~34%.