近年來，光學雷達 (Light Detection And Ranging, LiDAR) 技術不斷成長與突破，在科技領域中迅速發展。此技術在自動駕駛、無人機導航與安全監控等領域被廣泛應用，為我們生活帶來了許多便利性與安全性。目前在 LiDAR 感測器技術研究上，常見之系統有兩種為頻率調變連續波 (Frequency-Modulated Continuous Wave, FMCW) 與飛時測距 (Time of Flight, ToF)，而 FMCW LiDAR 具有較高之解析度與較長之工作距離，並且在環境抗噪能力與精準度上也有較好之表現。但由於 FMCW LiDAR 系統體積龐大以及需要更高之光源要求，使其在消費性電子產品應用受到限制，因此難以商業化量產。為改善其問題，目前 FMCW LiDAR 量測速度之研究團隊主要分為兩種，第一種為使用修正之光源進行量測，但此方法會使得系統複雜且昂貴，目前有研究團隊利用任意波形產生器 (Arbitrary Waveform Generators, AWG) 結合分佈式回饋布拉格 (Distributed Feedback Bragg, DFB) 光柵光源進行量測，其實驗主要專注於將光源通過疊代法不斷優化，以改善非線性現象。但此量測方法會導致物體測量時間增加，由於疊代法需要進行多次反覆優化步驟，因此若在複雜之雷射非線性時，需要相對較長時間才能將光源收斂至可用於量測之狀態。另一種為使用輔助干涉儀重採樣進行速度之量測，目前研究量測之速度皆低於 10 mm/s，對於目前商業化之產品應用較不足夠。由於 LiDAR 產品主要使用在即時量測系統，若計算時間過長會造成無法取得即時資訊，本實驗研究為不改變光源之情況下，提高量測速度與縮小系統體積，提升其在市面上之競爭力。
​本論文系統主要為利用 FMCW LiDAR 量測物體移動之速度，詳細介紹系統所使用之量測方法與計算方式。為了後續將此系統積體化，文中也介紹了矽光子耦合元件、矽光子分光器與 PIN 光偵測器之製程步驟。由 FMCW LiDAR 量測實驗證明，由於步進馬達產生之振動影響巨大，靜態座標系與動態座標系兩者之瞬時頻率變化趨勢不同，從而無法利用輔助干涉儀重採樣量測較高之物體移動速度。本論文發現若利用主要干涉儀之Hilbert Transformation進行重採樣，可提高量測之速度。實驗顯示光纖系統之量測速度為 200 mm/s 時，速度誤差為 1.097 mm/s，標準差可達 0.190 mm/s。當將主要干涉儀更換為矽光波導之50:50馬赫-曾德爾定向耦合器 (Mach-Zehnder Direction Coupler, MZDC)之分光能量器，此部分系統積體化之實驗結果得到量測速度為 200 mm/s 時，速度誤差為 1.378 mm/s，則標準差為 0.200 mm/s。

In recent years, Light Detection and Ranging (LiDAR) technology has been growing and advancing rapidly in the field of technology. It has been widely applied in various areas, such as autonomous driving, drone navigation, and safety monitoring, bringing convenience and security to our lives. Currently, there are two standard LiDAR sensing techniques: Frequency-Modulated Continuous Wave (FMCW) and Time of Flight (ToF). FMCW LiDAR offers higher resolution, more extended range, and better environmental noise resistance and accuracy performance. However, the bulky size and higher light source requirements of FMCW LiDAR systems limit their commercial mass production and consumer electronic applications. To address these challenges, current research teams working on FMCW LiDAR velocity measurements mainly focus on two approaches. The first approach involves correcting light sources in the experimental system to characterize the velocity. However, this approach makes the system complex and expensive. Currently, some research teams use arbitrary waveform generators (AWG) combined with distributed feedback Bragg (DFB) gratings in the light source to improve non-linear phenomena through iterative optimization for the velocity test. This method increases the object measurement time because of multiple optimization iterations. Therefore, it takes a relatively long time to converge the light source to a suitable state for FMCW velocity measurements when dealing with complex laser non-linearities. The second approach utilizes auxiliary interferometers for resampling in the velocity test. However, the research teams only achieve velocities below ten mm/s, which is insufficient for commercial product applications. Therefore, our study aims to improve the measurement velocity and reduce the system size to enhance its competitiveness in the market.
​This thesis focuses on using FMCW LiDAR to characterize the velocity of moving objects and provides detailed explanations of measurement methodologies and calculation procedures employed in the system. We also demonstrate the coupling elements in silicon photonics, silicon-waveguide splitters, and PIN photodetectors to enable future chip integration. The FMCW LiDAR velocity test experiments illustrate that the significant vibrations generated by the stepping motor result in different instantaneous frequency variations between the static and dynamic coordinate systems. Consequently, using auxiliary interferometers for resampling to measure objects in high velocities is not feasible. This thesis proposes to utilize the main interferometer in resampling through Hilbert transformation for FMCW velocity tests. The experimental results of the fiber optic system reveal that at a measurement velocity of 200 mm/s, the velocity error is 1.097 mm/s, and the standard deviation is 0.190 mm/s. For the system size reduction, the fiber optic coupler in the main interferometer is replaced with a 50:50 splitting ratio of Mach-Zehnder Direction Coupler (MZDC) in a silicon platform. The chip-based FMCW velocity system shows that at a measurement velocity of 200 mm/s, the velocity error is 1.378 mm/s, and the standard deviation is 0.200 mm/s.

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