Abstract
Vertical-cavity surface-emitting lasers have become important optical source for the applications such as new types as displays and optical fiber communications. In this paper,we adopt the method of proton-implantation to fabricate the VCSELs with the wavelength of 850 nm using AlxGa1-xAs/GaAs as the DBR pairs and AlxGa1-xAs/GaAs quantum-wells as the active layer. From the measurements of proton-implanted 850 nm VCSELs,we have the following results: the threshold current can be lower than 10 mA and the maximum light output power can reach 5 mW.Between some temperature range, the threshold current can remain unchanged due to the design of gain-offset. The F-P mode wavelength at some fixed current above threshold is observed to increase linearly with heat-sink temperature by 0.065 nm/℃,in good agreement with some reported papers.Besides, we have measured the far-field angle for different aperture sizes such as 4μm、6μm、8μm、10μm and 12μm having the results of 9°、8°、6°and 4.8°.For the measurement of dynamic characteristics we have successfully made the operating speed of the devices up to 1.25 Gbit/s. Due to the limit of the implant energy we used in the experiment, the excellent current confinement can not be made. We believe that by using much higher implant energy the threshold current can be much lower and the other characteristics can be improved.