本文選題：飛秒光梳 + 多波長　； 參考：《國防科學技術大學》2015年博士論文

【摘要】：激光以其單色性和相干性好、方向性強等優(yōu)點,被廣泛用于精密工程與測量領域。激光測距技術是目前動態(tài)量程最大、精度最高的長度和距離測量手段,在工業(yè)生產、裝備制造、國防科技和航空航天等領域發(fā)揮著至關重要的作用。隨著現代工業(yè)對大尺寸精密測量和定位技術需求的不斷提升,傳統(tǒng)的激光非相干和相干測距方法已經難以滿足大尺寸高精度距離測量的需求。飛秒激光光學頻率梳作為本世紀初最偉大的物理學貢獻之一,不僅實現了光學頻率和微波頻率的對接,而且?guī)砹司嚯x測量技術和長度計量實現手段的革新,其通過在傳統(tǒng)激光脈沖測距中引入光學相干技術,將非相干和相干測量完美地融合在一起,創(chuàng)新性地解決了大距離和高精度的突出矛盾,為實現大尺寸高精度激光絕對測距提供了諸多新方法和新技術。論文以實現大尺寸高精度實時絕對距離測量為任務,開展利用飛秒光梳時頻特性來實現絕對測距的理論和方法研究,特別是圍繞基于飛秒光梳同步鎖頻的多波長干涉實時絕對測距方法進行了系統(tǒng)的深入研究。論文的主要工作總結如下:1、提出了一種雙飛秒光梳多外差絕對測距方法。結合雙光梳互相關多外差測量和梳間拍頻測量,構建微波合成波長鏈,不需要掃描重復頻率便可在km量程內實現理論精度為亞微米量級的絕對測距;建立了該方法的測距理論模型,并仿真驗證了該方法用于開展大尺寸高精度絕對測距的可行性;利用飛秒脈沖的強度互相關特性建立了掃描重復頻率的互相關空間絕對測距模型,對現有的光梳時域互相關測距方法進行了改進,并通過建模與仿真分析證明了其可行性。2、提出了基于飛秒光梳同步鎖頻的多波長干涉實時絕對測距方法。針對傳統(tǒng)多波長干涉光源難以制備以及使用波長掃描干涉難以滿足實時測量需求等大尺寸絕對測距問題,從飛秒光梳的精密頻率尺特性出發(fā),本文提出了基于飛秒光梳同步鎖頻的多波長干涉實時絕對測距方法。該方法以飛秒光梳作為激光頻率參考源,利用光學鎖相技術同時產生多路波長相異、頻率穩(wěn)定度高的單波長激光來進行干涉測量,并通過多波長干涉相位的同步探測和小數重合算法拓展實時測距的非模糊度量程,測量結果不僅能保留單波長激光干涉測量的分辨力和精度,而且可溯源至微波頻率基準,對復現“米”的定義和長度計量具有重要意義。3、提出了二次等效合成波長拓展測距非模糊度的方法。針對多波長干涉中僅靠一次等效合成波長難以滿足大尺寸絕對測距中波長解調的問題,本文提出了二次等效合成波長的方法,通過兩個一次等效合成波長的再次合成克服了波長間隔的限制;在此基礎上,還深入研究了多波長干涉測距解調算法、波長選擇和非模糊度量程等問題,并仿真驗證了基于飛秒光梳同步鎖頻的四波長干涉非模糊度量程一般能達到36 mm,五波長干涉能達到米量級。4、圍繞產生高頻率穩(wěn)定度的多波長激光光源,在光纖飛秒脈沖激光光源基礎上,利用光學倍頻、f-2f自參考干涉和鎖相技術實現了重復頻率和載波包絡頻移的鎖定,使用Allan方差表征的相對頻率穩(wěn)定度分別達到1.1×10-12和5.1×10-15,實現了飛秒光梳的制備;在所搭建的飛秒光梳頻率參考源基礎上,利用光學鎖相技術將多個可調諧單波長激光同時鎖頻到不同的光梳梳模上,得到了相對鎖頻穩(wěn)定度為1.9×10-15的連續(xù)波輸出,實現了高頻率穩(wěn)定度的多波長光學頻率發(fā)生器裝置;針對所提多波長干涉法實現多路同步干涉測量的需求,研制了多波長外差干涉儀光路和多路同步相位解調模塊,實現了多波長測距系統(tǒng)的無混疊干涉、波長解調和小數相位精度優(yōu)于0.001(相對弧度制相位2π)的同步相位測量;研制了實時絕對測距算法及軟件,提高了小數重合法計算整數相位的效率,實現了更新速率為10 ms的連續(xù)測量,較好地滿足了實時絕對測距的需求。5、搭建了基于飛秒光梳同步鎖頻的多波長干涉絕對測距系統(tǒng)及其實驗平臺,并利用頻率掃描法實現了mm精度的初始絕對距離值的粗測。在此基礎上,進行了非模糊度量程驗證實驗和線性位移對比試驗。通過與雙頻激光干涉儀測量結果對比,證明了四波長干涉非模糊度量程達到44.6 mm,且1m線性位移內測量殘余誤差的P.V值為61.9 nm,相對測距精度達到了10-8量級,證明了所搭建的多波長干涉絕對測距系統(tǒng)開展大尺寸納米精度距離測量的可行性。6、提出了結合微波合成波長和多波長干涉進一步拓展非模糊度量程的方法。針對五波長干涉中使用二次等效合成波長拓展非模糊度量程的有限性,提出在四波長干涉基礎上融合微波合成波長測距的思想,大大提高了合成波長鏈拓展測距量程的效率。在所提方法基礎上,開展了3m大量程的線性位移對比測量實驗,與參考位移值的擬合殘差的P.V值為35.3 nm;同時,開展了抗光路中斷實時絕對測距實驗、短時測量性能對比試驗和24h長時測距性能對比實驗,從抗光路擾斷、測量分辨力、短時精度、長時間穩(wěn)定性和防死區(qū)光程誤差等方面展現了多波長絕對測距系統(tǒng)的良好測量性能及其應用潛力;對多波長干涉絕對測距的測量不確定度進行了分析和總結,并圍繞空氣折射率變化對準確判斷整數相位的影響及其與多波長干涉測距量程之間的關系進行了探討。
[Abstract]:Laser is widely used in the field of precision engineering and measurement for its advantages of good monochromability, good coherence and strong direction. Laser ranging is the largest and most accurate measure of length and distance in the dynamic range. It plays a vital role in the fields of industrial production, equipment manufacturing, national defense science and technology and aerospace. The demand for large size precision measurement and positioning technology has been improved in industry. Traditional laser incoherent and coherent distance measurement methods have been difficult to meet the needs of large size and high-precision distance measurement. The femtosecond laser optical frequency comb is one of the greatest physical contributions in the beginning of this century, which not only realizes the pair of optical frequency and microwave frequency. In addition, it brings the innovation of distance measurement and length measurement. Through the introduction of optical coherence technology in the traditional laser pulse distance measurement, it combines the noncoherent and coherent measurement perfectly. It innovatively solves the prominent contradiction between the large distance and the high precision, and provides the large size and high precision laser absolute distance measurement. In order to realize the real time absolute distance measurement with large size and high precision as the task, the theory and method of the absolute distance measurement using the time frequency characteristics of the femtosecond comb are carried out, especially the system of the multi wavelength interference real-time absolute distance measurement based on the femtosecond comb synchronous locking. The main work of this paper is summarized as follows: 1, a method of multi heterodyne absolute distance measurement for two femtosecond combs is proposed. Combining the cross correlation multi heterodyne measurement and beat frequency measurement, the microwave synthesis wavelength chain is constructed, and the absolute distance of the theoretical degree of sub micron can be realized within the km range without the need of scanning repetition frequency. The distance measurement model of the method is used to verify the feasibility of the method for large size and high precision absolute distance measurement. Using the intensity cross correlation characteristic of the femtosecond pulse, the absolute distance measurement model of the cross correlation space of the scanning repetition frequency is established, and the existing method of the cross correlation distance measurement of the current comb is improved and the modeling and simulation are made. The analysis proves its feasibility.2, and proposes a multi wavelength interferometric real-time absolute distance measurement method based on the femtosecond comb synchronous locking frequency. It is difficult to prepare the traditional multi wavelength interference light source and use the wavelength scanning interference to meet the real time measurement requirement. In this paper, a multi wavelength interferometric real-time absolute distance measurement method based on femtosecond comb synchronous locking is proposed. This method uses femtosecond comb as the reference source of the laser frequency, and produces a single wavelength laser with multi wavelength different wavelengths and high frequency stability by using optical phase locking technique. The small number coincidence algorithm extends the non fuzzy range of real-time distance measurement. The measurement results not only retain the resolution and accuracy of the single wavelength laser interferometry, but also be traced to the microwave frequency reference. It is of great significance to the definition and length measurement of the reiterative "rice".3. The two times of the equivalent synthetic wavelengths to extend the non ambiguity of distance measurement are proposed. Method. Aiming at the problem that only one equivalent synthetic wavelength in multi wavelength interference is difficult to satisfy the problem of wavelength demodulation in large size absolute distance measurement, this paper proposes a method of two equivalent synthetic wavelengths, which overcomes the limitation of wavelength interval through the resynthesis of two first equivalent synthetic wavelengths, and on this basis, the multi wavelength interferometry is also studied. From the demodulation algorithm, the wavelength selection and the non ambiguity range, the simulation shows that the four wavelength interference non ambiguity range based on the femtosecond comb synchronous locking frequency can reach 36 mm, the five wavelength interference can reach the meter.4, and the multi wavelength light source with high frequency stability is based on the fiber femtosecond laser light source. By using optical frequency doubling, f-2f self reference interference and phase locked technique have realized the locking of repetition frequency and carrier envelope frequency shift. The relative frequency stability characterized by Allan variance is 1.1 * 10-12 and 5.1 * 10-15 respectively. The preparation of femtosecond combs is realized. Multiple tunable single wavelength lasers are locked to different comb modes at the same time, and the frequency lock stability is 1.9 * 10-15 continuous wave output, and a multi wavelength optical frequency generator with high frequency stability is realized. The multi wavelength heterodyne interferometry is developed for the multi wavelength interference measurement for the multi wavelength interference method. The optical path and the multi-channel synchronous phase demodulation module have realized the non aliasing interference of the multi wavelength range finding system. The wavelength demodulation and the fractional phase precision are better than 0.001 (relative radian phase 2 pi). The real-time absolute distance measurement algorithm and software are developed, which improves the efficiency of the integer phase and realizes the update speed. The continuous measurement of 10 ms has satisfactorily satisfied the requirement of real time absolute distance measurement, and set up a multi wavelength interferometric absolute distance measuring system based on femtosecond comb synchronous locking and its experimental platform. The initial absolute distance of MM precision is measured by frequency scanning. On this basis, a non fuzzy range verification experiment is carried out. Compared with the linear displacement contrast test, by comparison with the measurement results of double frequency laser interferometer, it is proved that the four wavelength interference non ambiguity range reaches 44.6 mm, and the P.V value of the residual error in the 1m linear displacement measurement is 61.9 nm, and the relative distance precision reaches 10-8 order of magnitude. The feasibility of nanometer precision distance measurement.6 is proposed. A method is proposed to further expand the non fuzzy range with microwave synthetic wavelength and multi wavelength interference. Aiming at the limitation of using two equivalent synthetic wavelengths to extend the non fuzzy range in the five wavelength interference, the idea of combining microwave synthesis wavelength ranging on the basis of four wavelength interferometry is proposed. On the basis of the proposed method, the linear displacement contrast measurement experiment of 3M is carried out on the basis of the proposed method. The P.V value of the fitting residual of the reference displacement value is 35.3 nm. At the same time, the real time absolute distance measurement experiment, the short time measurement performance comparison test and the long time range finder of the 24h are carried out. The comparison experiment shows the good measurement performance and the application potential of the multi wavelength absolute distance measuring system from the anti optical path disturbance, the measurement resolution, the short-time precision, the long time stability and the light path error of the dead zone. The measurement uncertainty of the multi wavelength interferometric absolute distance measurement is analyzed and summarized, and the change of the refractive index of the air is around. The relationship between the integer phase and the range of multi wavelength interferometry is discussed.
【學位授予單位】：國防科學技術大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TN24
，

本文編號：1950896