【摘要】：隨著量子光學和量子信息科學的發(fā)展,人們發(fā)現(xiàn)量子噪聲壓縮和量子糾纏是非常重要的量子資源,可以在信息與計算領域完成經(jīng)典物理不可能完成的工作,諸如利用糾纏態(tài)光場實現(xiàn)量子離物傳態(tài)、量子密集編碼、量子糾纏交換及量子計算等。近年來,量子信息科學正朝著實用化方向發(fā)展,而作為連續(xù)變量量子信息處理必備的非經(jīng)典光源的壓縮態(tài)光場及通過壓縮態(tài)光場構(gòu)建的EPR糾纏態(tài)光場,必須具備小型化、集成化、數(shù)字化、能夠長時間穩(wěn)定運轉(zhuǎn)的特點。全固態(tài)雙波長連續(xù)單頻激光器,是產(chǎn)生連續(xù)變量壓縮態(tài)光場的最重要組成部分。首先在連續(xù)變量壓縮態(tài)光場產(chǎn)生過程中,作為泵浦源的全固態(tài)雙波長單頻激光器產(chǎn)生的相干態(tài)光場被分別用作簡并光學參量放大器DOPA的抽運光和種子光,其次在壓縮態(tài)光場的平衡零拍探測系統(tǒng)中,激光器輸出的基頻光(相干態(tài))作為本地振蕩光來放大待測的微弱信號光(壓縮態(tài)),并生成相應的散粒噪聲基準。因此全固態(tài)雙波長單頻激光器性能的好壞將直接影響壓縮態(tài)光場壓縮度的產(chǎn)生和測量。為了獲得穩(wěn)定的高功率、單頻以及理想光束質(zhì)量的激光輸出,山西大學光電研究所相關(guān)實驗小組提出了一系列針對激光器腔形設計方面的實驗解決方案,而我們則將注意力更多的放在如何設計優(yōu)化激光器的控制系統(tǒng)上,針對激光器系統(tǒng)要求溫度控制系統(tǒng)不僅具有精度高而且穩(wěn)定度高的特點,設計了高精度溫度控制系統(tǒng)。同時,為了最終得到可實用化的連續(xù)變量壓縮源系統(tǒng),我們對溫度控制系統(tǒng)進行了小型化、智能化、低能耗等性能的優(yōu)化,從而提高整個非經(jīng)典光源系統(tǒng)的性能。在實驗中不僅需要產(chǎn)生穩(wěn)定的高壓縮度的壓縮態(tài)光場,并且準確測量其壓縮度同等重要。為了尋求一種能夠準確測量量子噪聲抑制的探測方法,許多實驗小組也開展了高性能探測器方面的實驗研究,而平衡零拍探測方法由于具有能夠有效地降低經(jīng)典噪聲,放大信號光和直接表征信號光的正交分量起伏量的優(yōu)點,而成為連續(xù)變量量子信息科學研究中測量壓縮態(tài)量子噪聲的最佳方法之一。本論文的主要研究內(nèi)容及取得的成果如下：1、完成了小型化的連續(xù)變量壓縮源控制系統(tǒng)的研制,并將其應用到波長為1.06μm的壓縮源整機系統(tǒng)中,該整套樣機已提供給中國空間技術(shù)研究院508所用于量子空間遙感技術(shù)的研究,并獲得較高評價。該控制系統(tǒng)實現(xiàn)了小型化、智能化的激光器控制系統(tǒng)、一體化的鎖定控制系統(tǒng)和高性能的平衡零拍探測系統(tǒng)。2、研制開發(fā)了小型化、智能化的高精度數(shù)字溫度控制系統(tǒng),并將其配套于全固態(tài)單頻綠光激光器中,通過軟件設計實現(xiàn)了系統(tǒng)的自動開關(guān)機過程,工作過程中各路溫度失控時的自動報警及保護功能,現(xiàn)已將其作為產(chǎn)品在全國多處科研院所應用。高精度數(shù)字溫度控制系統(tǒng)結(jié)合變速積分PID控制算法,利用分辨率高達14位的HRPWM技術(shù)控制雙路全橋驅(qū)動器為TEC提供最大14A的電流,同時,對系統(tǒng)中的常溫溫度控制和高溫溫度控制部分分別采用恒流源和恒壓源方式作為溫度檢測電路。從而提高了溫度控制系統(tǒng)的控制精度和能力。該系統(tǒng)同時含有四路獨立的常溫控溫(10-40℃)模塊和一路高溫(120-160℃)控溫模塊,系統(tǒng)各路的控溫精度均優(yōu)于±0.005℃。最終提高了全固態(tài)連續(xù)單頻激光器功率及頻率穩(wěn)定性,從而有效改善了壓縮態(tài)光場的穩(wěn)定性。3、基于平衡零拍探測的理論,利用干涉效率和共模抑制比的概念,定量地分析了非理想平衡零拍探測對測量壓縮度的影響,構(gòu)建了測量偏差、實際壓縮度、50/50分束器的分束比、干涉效率和共模抑相比的關(guān)系,這對于通過測量的壓縮度來分析壓縮態(tài)的實際壓縮度非常重要。4、基于平衡零拍探測器的自減方案,以及對光電二極管的等效電路的分析,得到兩個光電二極管的光電流對共模抑制比的影響分為兩方面,即光電流的振幅差異和位相差異。由光電管的量子效率和暗電流引起的光電流的振幅差異可以通過精細的調(diào)節(jié)分束器的分數(shù)比來得以補償。而由光電管的等效電容和串聯(lián)電阻引起的光電流的位相差異通過差分微調(diào)電路和可調(diào)的偏置電壓來得以補償。最終完成了低噪聲、高增益和高共模抑制比的平衡零拍探測器的設計并將其產(chǎn)品化,在探測器中安裝任意兩個ETX500,我們獲得了激光功率1mW時散粒噪聲譜在2MHz處高于電子學噪聲20dB,探測器的飽和功率為54mW,共模抑制比為75.2dB。該探測器能很好地滿足壓縮態(tài)探測對低噪聲、高增益、高飽和功率及高共模抑制比的要求。
[Abstract]:With the development of quantum optics and quantum information science, it is found that quantum noise compression and quantum entanglement are very important quantum resources, and can complete the work of the classical physical impossibility in the field of information and calculation, such as using the entangled state light field to realize the quantum separation state, Quantum dense coding, quantum entanglement exchange and quantum computation, etc. In recent years, the quantum information science is developing in the practical direction, and as a necessary non-classical light source in the continuous variable quantum information processing and the EPR entangled state light field constructed by the compressed state light field, the quantum information science has to be miniaturized, integrated, digitized, and can be stably operated for a long time. All-solid-state dual-wavelength continuous single-frequency laser is one of the most important components of a continuous variable compression state optical field. firstly, in a continuous variable compression state light field generation process, the coherent state light field generated as an all-solid-state dual-wavelength single-frequency laser as a pump source is used as the pumping light and the seed light of the degenerate optical parametric amplifier DOPA, respectively, The fundamental frequency light (coherent state) output by the laser is used as the local oscillation light to amplify the weak signal light (compressed state) to be measured, and a corresponding dispersion noise reference is generated. Therefore, the performance of all-solid-state dual-wavelength single-frequency laser will directly affect the generation and measurement of the compression degree of the squeezed optical field. In order to obtain stable high power, single-frequency and ideal beam quality laser output, the relevant experimental group of the Institute of photoelectric research of the University of Shanxi University has proposed a series of experimental solutions for laser cavity-shaped design. And we focus more on how to design and optimize the control system of the laser, and the high-precision temperature control system is designed for the laser system, which requires the temperature control system not only has the characteristics of high precision and high stability. At the same time, in order to get a practical continuous variable compression source system, we have carried out the optimization of the temperature control system, such as miniaturization, intellectualization, low energy consumption and so on, so as to improve the performance of the whole non-classical light source system. In the experiment, it is not only necessary to produce a steady high-compression-state optical field, but also to measure the degree of compression equally important. In order to find a detection method capable of accurately measuring the quantum noise suppression, many experimental groups have also carried out the experimental research on the high-performance detector, and the balanced zero-beat detection method has the advantages of being capable of effectively reducing the classical noise, It is one of the best ways to measure the quantum noise of compressed state in the research of quantum information of continuous variable. The main research contents and achievements of this paper are as follows: 1. The development of a miniaturized continuous variable compression source control system is completed, and it is applied to a compressed source system with a wavelength of 1.06. m The prototype has been provided to the Chinese Academy of Space Technology 508 for the research of the quantum space remote sensing technology, and has obtained a higher evaluation. the control system realizes the miniaturization, the intelligent laser control system, the integrated lock control system and the high-performance balanced zero-shooting detection system. and it is matched with all-solid-state single-frequency green light laser, and the automatic switch machine process of the system is realized through the software design, and the automatic alarm and protection function during the control of each temperature in the working process is realized, and the automatic switch machine has been applied as a product in a plurality of scientific research institutions throughout the country. The high-precision digital temperature control system combines the variable speed integral PID control algorithm to control the two-way full-bridge driver to provide the maximum 14A current to the TEC by using the HRPWM technology with high resolution up to 14 bits, and meanwhile, the normal-temperature temperature control and the high-temperature temperature control part in the system are used as the temperature detection circuit by using a constant current source and a constant voltage source respectively. so that the control precision and the capability of the temperature control system are improved. The system also contains four independent temperature control modules (10-40 鈩，

本文編號：2396822