我們製作一個高效能鋅擴散850nm波段的單模態面射型雷射。其元件擁有較低的臨限電流0.5mA、較高的微分量子效率（80%）及電流調制效率為8.2 GHz/mA1/2，從低的臨限電流至高的飽和電流下元件皆維持穩定的單模態操作，而最大的輸出光功率達到7.3mW。其元件在一個小的操作電流(1.8mA)及較小信號偏壓（0.5Vp-p）就可以使10 Gb/s的眼圖打開及其元件的傳輸量比功率消耗率為6.5 Gps/mW。
然而此高功率單模面射型雷射依然存在空間電洞不足問題，此效應使元件之頻寬在低頻時即有滑落之現象；欲改善此問題，我們製作了三種具有不同鋅擴散深度的元件，進而比較其直流及高頻特性，實驗後發現擴散深度介於中間之元件，可以改善先前所提及之低頻滑落現象，而其激發之光點可在空間中保持單模態操作，與多模態操作之元件相比有一個較好的對準誤差，因此此元件在具有多模態雷射之高頻特性下，亦同時擁有單模態雷射之高對準誤差，同時藉由通過10 Gb/s的眼圖，更證明此最佳化元件可達到高速、低消耗功率的目標。

We demonstrate a high-performance Zn-diffusion single-mode 850nm vertical-cavity surface-emitting laser, which has a low threshold current （0.5 mA）, high differential efficiency（80%）, high modulation current efficiency （8.2 GHz/mA1/2）, and can sustain the single fundamental-mode output with a maximum output power of 7.3 mW under the full range of bias currents. With this device we can achieve 10 Gb/s eye-opening at a low bias current （1.8 mA） and a peak-to-peak driving-voltage of 0.5 V, which corresponds to a very high data-rate/power-dissipation ratio of 6.5 Gps/mW.
However, this device still suffers form the low-frequency roll-off caused by the spatial hole burning (SHB) effect, and degrades the speed performance. In order to solve the mentioned problem, we fabricated the devices with three different depth of Zn-diffusion to compare their DC and RF characteristics. According to our experiment results, we can find that minimization of low-frequency roll-off has been observed in the device with middle depth of Zn-diffusion, and the lasing spot can still maintain spatial single-mode which the alignment tolerance is larger then the multimode device. Therefore, the demonstrated device can have high speed performance of multimode device and the large alignment tolerance of single mode device at the same time. In light of the clearly opened eye-pattern at 10 Gb/s operating speed, we can further evidence that our device can achieve high-speed, low power-dissipation performance.

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