運用850光波段的垂直共振腔體面射型雷射搭載正交分頻多工調變於光互連系統

Abstract

於此篇論文中，我們探討運用850光波段的垂直共振腔面射型雷射(VCSEL)在光頻譜寬度和調變速度的權衡，和它運用在正交分頻多工(OFDM)的影響。研究兩種不同的元件:高速和高功率分別有不同的共振腔長度(λ/2和3λ/2)。藉由縮短共振腔長度至λ/2，和鋅擴散製程，可以達到高速(~16GHz)和雙模態的表現，對比同共振腔長的多模雷射，它的傳輸速率與距離比掉得比較慢。另一方面，共振腔長度3λ/2且運用相同的鋅擴散條件，可以達到高側模抑制比(SMSR)大於35dB和高輸出功率。雖然3-dB頻寬較小(12 vs. 16 GHz)，它在正交分頻多工的傳輸上有較好的結果，在前向錯誤修正(FEC)的界線(誤碼率(BER)小於 3.8×10-3)下達成新紀錄的速率×距離(BRDP) 107.6 Gb/s·km。此外，在無誤差的界線(誤碼率小於1×10-12)下，達到速率×距離44.66 Gb/s·km。

In this thesis, we investigate the trade-off between optical spectral width and modulation speed of 850 nm Zn-diffusion VCSEL and its influence on the performance of OFDM modulation, two kinds of devices for high-speed and high-power with different cavity lengths (λ/2 and 3λ/2) are studied. By shortening the cavity length to λ/2 and Zn-diffusion processes. High-speed performance (~16GHz bandwidth) and dual-mode characteristic can be achieved. Compared with its multimode reference, it shows far less roll-off with regard to the maximum data rate versus transmission distance over OM4 multimode fibers (MMFs). On the other hand, for the 3λ/2 VCSEL structure, by using the same Zn-diffusion conditions, highly single-mode operation (SMSR>35dB) with high available power can be achieved. Although such device shows a smaller 3-dB bandwidth (12 vs. 16 GHz), it exhibits a superior transmission performance by use of OFDM modulation format. Record-high bit-rate distance product (BRDP) (107.6 Gb/s·km) at nearly 50 Gb/s transmission under FEC threshold (BER< 3.8×10-3) through 2.2 km OM4 fibers has been successfully demonstrated. In addition, error-free (BER< 1×10-12) transmission at 20.3 Gb/s with BRDP of 44.66 Gb/s·km has also been demonstrated.