本文選題：超窄線寬激光　切入點：Pound-Drever-Hall技術(shù)　出處：《中國科學院研究生院（國家授時中心）》2015年碩士論文　論文類型：學位論文

【摘要】：基于光纖的光學頻率傳遞是目前精度最高的頻率傳遞手段。2012年,德國MPQ-PTB聯(lián)合小組在千公里級實地光纖上實現(xiàn)了10-18/3000s量級的傳遞穩(wěn)定度,為未來利用光纖實現(xiàn)遠距離光鐘比對奠定了技術(shù)基礎(chǔ)。在光纖光學頻率傳遞研究中,利用窄線寬激光作為傳遞光源,是實現(xiàn)超高精度頻率傳遞的關(guān)鍵之一,與現(xiàn)有光通信網(wǎng)相兼容,是擴展光纖光學頻率傳遞應用范圍的必然選擇。因此,圍繞光學頻率傳遞對光源的需求,主要完成了1550nm窄線寬激光器的初步研究,并在實驗室環(huán)境的條件下,實現(xiàn)了其在光纖光學頻率傳遞中的初步應用。實驗上,我們采用傳統(tǒng)的Pound-Drever-Hall(PDH)頻率穩(wěn)定技術(shù)實現(xiàn)了1550nm窄線寬激光器的鎖定。實驗中,我們將激光器輸出的激光分為兩束分別鎖定到兩臺精細度分別為344000,296000的光學參考腔上。首先,通過對激光器PZT與聲光調(diào)制器的伺服控制將激光先鎖定到第一臺光學參考腔上,同時測得伺服系統(tǒng)的控制帶寬為50k Hz。然后,通過一根5m的光纖將穩(wěn)定后的激光傳遞到第二臺光學參考腔中,利用聲光調(diào)制器將激光再次鎖定到第二臺光學參考腔上,由于外界環(huán)境對光纖的影響,通過拍頻比對測得光纖導致激光頻率的展寬為0.27Hz。為了評估激光的頻率穩(wěn)定度及線寬,在第二套穩(wěn)頻激光伺服控制系統(tǒng)帶寬為4k Hz的條件下,通過頻譜分析儀及頻率計數(shù)器分別測得激光的線寬為2.7Hz,頻率穩(wěn)定度為2.5×10-14/s,在兩套激光特性相同情況下,則單臺激光的線寬優(yōu)于等于1.9Hz,頻率穩(wěn)定度優(yōu)于等于1.7×10-14/s。同時,我們將鎖定后的1550nm窄線寬激光應用于光纖光學頻率傳遞系統(tǒng)中,在實驗室環(huán)境中,測得50km光纖盤的光學頻率傳遞穩(wěn)定度為7.5×10-17/s,在相同條件下,測得光源線寬為k Hz量級激光時,光學頻率傳遞的穩(wěn)定為2.4×10-16/s。實驗中,我們采用安捷倫53232A,在自動模式下記錄激光的拍頻信號。最后,我們討論了窄線寬激光穩(wěn)頻系統(tǒng)中盡可能優(yōu)化的部分,包括光路的全光纖化、小型化、伺服控制系統(tǒng)帶寬及控制環(huán)路的時延的優(yōu)化。
[Abstract]:Optical fiber transmission frequency is currently the highest precision frequency transmission method based on.2012, the German MPQ-PTB group combined with 10-18/3000s to realize the transfer order of stability in the thousand kilometer level field for the future use of optical fiber optical fiber, thus laying the technical foundation to achieve long-distance optical clock comparison. In the study of optical frequency transfer, as the use of light transmission narrow linewidth laser, is one of the key to achieve ultra high precision frequency transfer, which is compatible with existing optical communication network, is the inevitable choice of expanding the scope of application of optical fiber transmission frequency. Therefore, the frequency of light around the optical transmission requirements, mainly to complete the preliminary study of 1550nm narrow linewidth laser, and the environmental conditions in the laboratory next, achieved its preliminary application in optical frequency transfer. In experiment, we use the traditional Pound-Drever-Hall (PDH) technology to achieve a stable frequency 1550nm紿勭嚎瀹芥縺鍏夊櫒鐨勯攣瀹，

本文編號：1578405