半導體雷射在光回饋系統作用下，會有各種非線性行動態產生，其中包含週期一震盪態、準週期震盪態及混沌態等等，而混沌態透過時域訊號計算自相關值可以得到時間延遲特徵，此現象因有特殊的週期性而不利應用於亂數產生器，本研究旨在運用不同的干涉技術抑制時間延遲特徵並分別探討其產生之混沌訊號在亂數產生器之效果。先利用延遲自相干涉法(Delayed Self-Interference, DSI) 作為整個研究之比較標準，此方法架構為光回饋系統輸出後利用~Mach–Zehnder Interferometer (MZI) 進行干涉，透過改變不同之干涉比例可以達到35%之抑制效果，我們將DSI改善，延遲自相外差干涉法(Delayed Self-Heterodyne Interference, DSHI) 透過設計循環頻率及移頻頻率，將移頻頻率設為循環頻率的一半，使干涉的兩道光在對應的強度時在頻域上降低原有之週期性，同時補足原本混沌態在低回饋強度時低頻訊號強度之不足，消除65%的時間延遲特徵。而損失補償循環延遲自相外差干涉法(Loss-Compensated Recirculating Delayed Self-Heterodyne Interferometer, LC-RDSHI) 利用前述之移頻條件，將原本就有一定隨機性的混沌態疊加，所產生之訊號有多重光干涉之效果，進而有更為混亂之訊號產生，此架構抑制時間延遲特徵之效果可以達到92%以上。除了時間延遲特徵外我們也同時比較了有效頻寬與標準頻寬，在三個干涉架構中以LC-RDSHI擁有最高之52%增益率。使用干涉法會在計算自相關值時有干涉之光程差所造成的訊號產生，為了驗證訊號的隨機程度，我們透過將不同方法之混沌干涉訊號處理後送入美國國家標準技術研究所之亂數碼產生標準(NIST Special Publication 800-22) 測試其隨機性質，測試結果顯示LC-RDSHI可以在取樣頻率10 GSa/s的條件下，將原本混沌訊號可以通過的3LSBs提升至5LSBs，產生50 Gbit/s的亂數速率，改善了DSI只能在低取樣頻率(1.25 Gbit/s)下達到5 LSBs的問題，我們也比較DSI、DSHI與LC-RDSHI應用於亂數產生器效果，發現DSI與DSHI都只能到3 LSBs，本研究之高速率亂數碼可用在保密通訊、軍事等領域。

Semiconductor laser can generate various nonlinear dynamical states by the action of optical feedback (OF) system including periodic-one oscillation state (P1), quasi-periodic oscillation state (QP), chaotic oscillation state (C) and so on. Through the calculation of autocorrelation of time series in chaotic oscillation state, we can find the time delay signature (TDS). This phenomenon is unfavorable to apply in random number generator~(RNG) because of it's special periodicity. In this study, TDS is suppressed and random number is generated by different interference techniques. First, we use the Delayed Self-Interference (DSI) to be the basic standard of comparison of the whole study. The setup of the DSI combined the OF system and Mach–Zehnder interferometer (MZI). With a proper power and feedback strength, the TDS reduction ratio can be up to 35%. Then we add a acousto-optic modulator (AOM) to improve the DSI, which called the Delayed Self-Heterodyne Interference (DSHI). Through the design of the external cavity length and the frequency of the AOM, the TDS reduction ratio can be up to 65%. We change the MZI setup to the Loss-Compensated Recirculating Delayed Self-Heterodyne Interferometer (LC-RDSHI). The LC-RDSHI chaos signal is equal to a multiple-beam interference results, which can suppress the TDS value more. We calculate the TDS reduction ratio of 92%. In addition, the effective bandwidth enhancement ratio can be up to 52%. On the other hand, we demonstrate the different interference techniques for generation of random number. The NIST Special Publication 800-22 Statistical Tests evaluated the randomness of chaos signal. The bit sequences of the LC-RDSHI signal can generate higher bit rate from 10 to 50 Gigabit per second than the DSI and the DSHI. The high random bit generation rates can be used to confidential communication and military application.

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