發(fā)布時間：2018-03-03 03:06

  本文選題：中紅外激光　切入點：光參量振蕩　出處：《山東大學》2017年博士論文　論文類型：學位論文

【摘要】：2-5 μm波段中紅外激光在大氣中具有較強的穿透能力,而且眾多原子及分子的特征吸收峰也坐落于該波段,因此該波段激光在前沿科學、軍事、光譜學、遙感探測、醫(yī)療診斷等諸多領(lǐng)域都具有極其重要的應用價值,該波段激光器一直是國防和民用領(lǐng)域競相研發(fā)的重點。利用光參量振蕩器(OPO)技術(shù),將成熟的近紅外波段激光進行頻率下轉(zhuǎn)換,能夠?qū)崿F(xiàn)中紅外波段激光的寬帶、連續(xù)調(diào)諧輸出,可以彌補一些離子摻雜(如Ho3+、Er3+ Tm3+)激光器在波長發(fā)射和調(diào)諧方面的不足。在眾多非線性晶體材料中,基于準相位匹配的光學超晶格材料,特別是周期極化鈮酸鋰或鉭酸鋰晶體(PPLN、PPLT),具有非線性系數(shù)大、通光范圍寬、波長調(diào)諧方式多樣、生長制備較為容易、適合于1064nm泵浦等優(yōu)點,是目前中紅外大功率OPO的理想選擇。拓寬中紅外激光輸出波長范圍,提高OPO的轉(zhuǎn)換效率、輸出功率、光束質(zhì)量和穩(wěn)定性一直都是人們研究的方向。針對這一命題,本論文將泵浦源設計、光束整形以及OPO諧振腔設計相結(jié)合,選用周期性極化摻鎂鈮酸鋰(PPMgO:LN)及化學計量比鉭酸鋰(PPSLT)晶體,實現(xiàn)了寬調(diào)諧窄線寬連續(xù)波,大能量長脈沖,多波長、寬調(diào)諧及高功率納秒脈沖中紅外OPO輸出。具體內(nèi)容主要包括:1.介紹了中紅外激光的重要應用,對目前產(chǎn)生中紅外激光的主要技術(shù)途徑進行了對比,并概述了光學超晶格OPO的研究現(xiàn)狀。2.簡單介紹了相位匹配技術(shù),描述了準相位匹配技術(shù)和實現(xiàn)波長調(diào)諧的原理與方法,對OPO基礎(chǔ)知識及設計基本原則進行了介紹。3.結(jié)合單塊非平面環(huán)形腔(NPRO)單頻激光器和混合腔(Innoslab)板條激光放大器,開展寬調(diào)諧、窄線寬連續(xù)波中紅外OPO研究。得到了 83.4 W、線寬17.69kHz的高功率 1064nm激光輸出;并在基于PPMgO:LN的環(huán)形腔OPO中,實現(xiàn)了 1344.6-5103.2 nm的寬調(diào)諧窄線寬中紅外激光輸出。4.采用具有高峰值功率的脈沖模式工作的激光二極管(LD)作為泵浦源,進行了大能量長脈沖中紅外OPO探索。以Nd:YVO4為激光增益介質(zhì),腔內(nèi)泵浦PPMgO:LN晶體,在結(jié)構(gòu)緊湊的直腔中,得到了大能量微秒量級脈沖參量光輸出,3.336、3.500、3.789 μm 處的單脈沖能量分別為 3.99、3.31、2.50 mJ。5.研究了多波長、寬調(diào)諧納秒中紅外OPO。針對OPO需要偏振激光泵浦的特點,利用偏振分束技術(shù),將由非偏振光纖激光分束后的兩路偏振光共同耦合進同一塊PPSLT晶體的兩個不同通道,在同一諧振腔中,實現(xiàn)了四波長激光同時輸出;利用多周期PPMgO:LN晶體,實現(xiàn)了 1346.6-5076.8 nm寬調(diào)諧納秒中紅外OPO輸出。6.利用調(diào)Q激光技術(shù),結(jié)合多級Innoslab板條放大器,對高功率中紅外OPO進行了研究。用側(cè)面抽運Nd:YLF調(diào)Q激光泵浦PPMgO:LN晶體,得到了單脈沖能量為1.1 mJ的3.796 μm中紅外激光輸出;以多級Innoslab板條放大器為OPO泵浦源,在3.791 μm和2 μm波段分別實現(xiàn)了 10.2 W和33.3 W的中紅外激光輸出。另外,在實驗基礎(chǔ)上進行工程化探索,設計并完成三臺寬調(diào)諧、高功率納秒中紅外OPO樣機,推動中紅外激光技術(shù)的研究與示范應用。
[Abstract]:2-5 m wavelength infrared laser has a strong penetrating ability in the atmosphere, and the characteristics of a large number of atomic and molecular absorption peak also located in the band, the band laser at the forefront of science, military, spectroscopy, remote sensing, has very important application value in many fields such as medical diagnosis, the lasers have been key military and civilian fields. With the development of the optical parametric oscillator (OPO) technology, the near-infrared laser frequency conversion to mature, can realize the broadband mid infrared laser, tunable output, can make up for some ions (such as Ho3+, Er3+ Tm3+) laser at the wavelength of emission and shortcomings in terms of tuning in many nonlinear crystals, quasi phase matching optical superlattice materials especially based on periodically poled lithium niobate or lithium tantalate crystals (PPLN, PPLT), with a nonlinear coefficient Large optical wavelength tuning range, diversity, growth and preparation is easy, suitable for 1064nm pumping and other advantages, is the ideal choice for high power infrared OPO currently. To broaden the mid infrared laser output wavelength range, improve the conversion efficiency of OPO, output power, beam quality and stability have been a research direction. According to this proposition, this paper will design the pump source, beam shaping and OPO cavity design combined with periodically poled MgO doped lithium niobate (PPMgO:LN) and stoichiometric lithium tantalate (PPSLT) crystals, can achieve a wide tunable continuous wave, high energy long pulse, multi wavelength, wide tuning and high power nanosecond pulse infrared OPO output. The specific contents include: 1. introduced important application in infrared laser, the main ways of technology to produce mid infrared laser at present are compared, and an overview of optical superlattice OPO Briefly introduces the research status of.2. phase matching technology, describes the technology and principle and method of realizing wavelength tuning of quasi phase matching of OPO, basic knowledge and basic design principles are introduced with.3. monolithic non planar ring cavity single frequency laser (NPRO) and mixed cavity (Innoslab) slab laser amplifier, carry out wide tuning. Study on infrared continuous wave OPO in narrow linewidth. By 83.4 W high power 1064nm laser linewidth of 17.69kHz; based on ring cavity OPO PPMgO:LN, 1344.6-5103.2 nm to achieve wide tunable narrow linewidth in the infrared laser light output.4. laser diode with high peak power pulsed mode (LD) as the the pump source, the high energy long pulse infrared OPO exploration. Using Nd:YVO4 as the laser gain medium pumped PPMgO:LN crystal, the straight cavity of a compact structure, the high energy nanosecond pulse 鍐插弬閲忓厜杈撳嚭,3.336,3.500,3.789 渭m 澶勭殑鍗曡剦鍐茶兘閲忓垎鍒負 3.99,3.31,2.50 mJ.5.鐮旂┒浜嗗娉㈤暱,瀹借皟璋愮撼縐掍腑綰㈠OPO.閽堝OPO闇，

本文編號：1559260