Summary: | 碩士 === 國立中央大學 === 電機工程研究所 === 95 === By utilizing the Zn-diffusion technique, we demonstrate a single-mode 850nm vertical-cavity surface-emitting laser (VCSEL) without greatly downscaling the diameter of oxide-confined aperture to minimize the thermal effect. The demonstrated device with a 9 μm active diameter can attain an 8GHz bandwidth, a
small differential resistance (~47Ω47Ω), a 3mW maximum output power, and sustain the
single-mode characteristic under dynamic operation and whole range of bias current.
According to the dynamic measurement results, our single-mode device can
eliminate the damping-limited bandwidth,which was observed in our multi-mode
control without the Zn-diffusion aperture, and has a larger intrinsic bandwidth
(31GHz vs. 17GHz) due to the elimination of mode competition effect. The
narrower divergence angle (80 vs. 200) means that the device exhibits a larger
alignment tolerance and much lower coupling loss when used with the standard
multi-mode fiber than those of the control sample.
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