本文關(guān)鍵詞： 光參量振蕩 受激拉曼散射 亞納秒 雙損耗調(diào)制 調(diào)Q 調(diào)Q鎖模 Nd MgO:LiTaO_3晶體 Nd MgO:LiNbO_3晶體 單層石墨烯 KTP　出處：《山東大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：自從1961年Franken等人利用石英晶體(Si02)實(shí)現(xiàn)倍頻,成功將紅寶石激光擴(kuò)展到紫外波段,第一次實(shí)現(xiàn)了真正意義的頻率變換以來(lái),非線性頻率變換就是激光科學(xué)范圍內(nèi)最吸引人的課題之一。目前,使用非線性光學(xué)晶體來(lái)實(shí)現(xiàn)頻率變換的技術(shù)是獲得新的相干光源最有效、最可靠也是最普遍的方法。非線性晶體的二階非線性效應(yīng)(即三波相互作用過(guò)程)和三階非線性效應(yīng)(即四波相互作用過(guò)程)都得到了深入而又廣泛的研究。在上述頻率變換技術(shù)中,頻率下轉(zhuǎn)換技術(shù),如差頻、光參量過(guò)程和受激拉曼散射,是最有潛力獲取中紅外相干光源的手段。本論文基于單塊KTP晶體分別使用調(diào)Q、雙調(diào)Q和調(diào)Q雙波長(zhǎng)激光器作為泵浦源實(shí)現(xiàn)了光參量振蕩和受激拉曼散射兩個(gè)過(guò)程,并建立一套耦合速率方程,對(duì)實(shí)驗(yàn)結(jié)果進(jìn)行了理論模擬和分析,結(jié)果表明兩者吻合得很好；使用克爾透鏡鎖模和雙損耗調(diào)制調(diào)Q鎖模激光器作為泵浦,首次實(shí)現(xiàn)了內(nèi)腔式鎖模激光泵浦的光參量振蕩器,輸出的脈寬在次納秒(Sub-nanosecond)量級(jí),并結(jié)合速率方程理論,建立理論模型,數(shù)值模擬和實(shí)驗(yàn)結(jié)果基本吻合；首次使用KTP作為拉曼增益介質(zhì),使用1050 nm Yb:YAG激光作為泵浦,成功獲得了高階Stokes光輸出,脈沖寬度約為764 ps,估算了KTP的有效增益系數(shù)；首次實(shí)現(xiàn)了W級(jí)σ偏振Nd,MgO:LiNbO3 1094 nm激光輸出,同時(shí)作為泵浦源,獲得了KTP OPO 1630 nm信號(hào)光。本論文的主要研究?jī)?nèi)容總結(jié)如下：(1)首次實(shí)現(xiàn)了單層石墨烯調(diào)Q Nd,MgO:LiTaO31082 nm和1092 nm雙波長(zhǎng)激光運(yùn)轉(zhuǎn),獲得了176 ns的最小脈寬和2.75μJ的最大單脈沖能量。(第二章第一節(jié))(2)首次實(shí)現(xiàn)了雙波長(zhǎng)調(diào)Q鎖模Nd:GGG激光輸出,調(diào)制深度近乎100%,脈寬估計(jì)為908 ps。(第二章第二節(jié))(3)以KTP晶體作為多功能非線性晶體,同時(shí)實(shí)現(xiàn)了高階Stokes和OPO信號(hào)光的振蕩輸出。在LD泵浦達(dá)到10.5 W時(shí),信號(hào)波的最大輸出功率高達(dá)302mW,最小脈寬僅1.61 ns,同時(shí)二階和三階Stokes光的最大功率為11 5 mW,最小脈寬為2.88 ns,波長(zhǎng)分別為1124.9和1160.7 nm。相應(yīng)的光光轉(zhuǎn)化效率為2.88%和1.1%。光束質(zhì)量因子M2在1.2左右。(第三章第一節(jié))(4)為進(jìn)一步壓縮信號(hào)光脈寬,采用雙損耗技術(shù),即同時(shí)使用兩種飽和吸收體,同時(shí)獲得了OPO和SRS過(guò)程,而且信號(hào)波輸出的最高功率為208 mW,脈沖寬度被壓縮到了580 ps,峰值功率提高到43.7 kW。當(dāng)調(diào)整KTP傾斜角度時(shí),首次觀察到波數(shù)為154 cm-1的頻移。(第三章第一節(jié))(5)、用Cr4+:YAG調(diào)Q的Nd:LGGG激光作為泵浦源,實(shí)現(xiàn)了雙波長(zhǎng)泵浦的多種非線性效應(yīng),即同時(shí)存在的SRS和OPO過(guò)程,信號(hào)光最大功率為448 mW,脈沖寬度為850 ps,信號(hào)光的峰值功率高達(dá)30.6 kW,單脈沖能量為26μJ,并從雙波長(zhǎng)速率方程出發(fā)對(duì)此過(guò)程進(jìn)行了理論研究。(第三章第二節(jié))(6)、首次用LD泵浦c切Nd,MgO:LiNbO3晶體,獲得了1.47 W的連續(xù)激光輸出,這是首次突破W級(jí)輸出,較之前的報(bào)道至少提高了20倍。用KTP晶體實(shí)現(xiàn)了OPO 1.63 μm信號(hào)光運(yùn)轉(zhuǎn),其脈沖寬度為1.69 ns,峰值功率為11.4 kW,較以前的報(bào)道提高了3倍。(第三章第三節(jié))(7)、首次實(shí)現(xiàn)了Yb:YAG 1050 nm激光泵浦KTP實(shí)現(xiàn)高階拉曼光輸出,三階Stokes光的脈寬約為764 ps。反Stokes光的脈寬為1.54 ns,峰值功率為3.5kW。光束質(zhì)量在兩個(gè)方向上分別為1.64和1.48,表明Stokes、基頻光和反Stokes光有很好的共線。KTP有效拉曼增益系數(shù)估計(jì)為2.1 cm/GW。(第三章第四節(jié))(8)、首次研究了KLM激光泵浦的內(nèi)腔OPO,用AOM選取鎖模脈沖提高峰值功率,分別用Nd:GGG和鍵合Nd:YVO4激光泵浦KTP,成功完成了高峰值功率、高能量的亞納秒1.57μm信號(hào)波輸出：其中KLM Nd:GGG/KTP OPO信號(hào)光的最高峰值功率為102 kW, KLM Nd:YVO4/KTP OPO信號(hào)波的最小脈寬約為120 ps,同時(shí)結(jié)合速率方程模擬了實(shí)驗(yàn)結(jié)果。(第四章第一、二節(jié))(9)、采用AO和Cr4+:YAG主被動(dòng)雙損耗QML激光作為腔內(nèi)OPO的泵浦光,并采用V型腔結(jié)構(gòu),在8.25 w的二極管泵浦情況下,AO的調(diào)制周期固定為1 ms(即重復(fù)率為1 kHz)時(shí)得到了信號(hào)光最高輸出能量為96μJ、包絡(luò)寬度為2.5 ns。當(dāng)聲光開關(guān)頻率在5 kHz時(shí)信號(hào)波輸出的功率達(dá)到最大,高達(dá)156 mW,也是目前QML激光泵浦內(nèi)腔式OPO信號(hào)光的最高輸出功率。同時(shí),信號(hào)光的光束質(zhì)量因子M2經(jīng)測(cè)小于1.5。(第五章第一節(jié))(10)、采用AO和Cr4+:YAG主被動(dòng)雙損耗技術(shù),首次獲得了單鎖模脈沖KTP OPO,當(dāng)二極管泵浦為10.5 W、聲光開關(guān)頻率為2 kHz時(shí),信號(hào)波的最小脈寬為450 ps,峰值功率高達(dá)35.5 kW,并研究了信號(hào)光輸出波長(zhǎng)與溫度之間的關(guān)系,發(fā)現(xiàn)其信號(hào)光波長(zhǎng)隨溫度的升高有0.027 nm/℃的藍(lán)移率。同時(shí)建立一套基于QML鎖模泵浦IOPO的速率方程,通過(guò)數(shù)值模擬發(fā)現(xiàn),脈沖波形和輸出能量基本和實(shí)驗(yàn)值一致。(第五章第二節(jié))本論文的主要?jiǎng)?chuàng)新點(diǎn)如下：(1)、首次利用單塊KTP晶體實(shí)現(xiàn)了高階Stokes光和光參量振蕩兩種非線性過(guò)程,光束質(zhì)量因子M2在1.2左右。(2)、首次實(shí)現(xiàn)了雙調(diào)Q激光器泵浦的受激拉曼散射和光參量振蕩過(guò)程,其中,信號(hào)光輸出脈沖寬度首次壓縮為580 ps。(3)、第一次實(shí)現(xiàn)了雙波長(zhǎng)激光器泵浦的多種非線性頻率下轉(zhuǎn)換過(guò)程,并建立了一套耦合速率方程,理論結(jié)果和實(shí)驗(yàn)結(jié)果基本吻合。(4)、首次實(shí)現(xiàn)了KLM激光器泵浦的內(nèi)腔式OPO運(yùn)轉(zhuǎn),實(shí)現(xiàn)了高峰值功率信號(hào)光輸出。(5)、第一次實(shí)現(xiàn)了主被動(dòng)雙損耗調(diào)制QML激光泵浦的內(nèi)腔式OPO,獲得了亞納秒信號(hào)光的穩(wěn)定輸出。(6)、首次成功獲得了單鎖模脈沖激光泵浦OPO,信號(hào)光脈寬約為450 ps,結(jié)合調(diào)Q鎖模激光的波動(dòng)機(jī)制,建立相應(yīng)的模型。(7)、實(shí)現(xiàn)了1150 nm Yb:YAG/KTP三階Stokes光輸出,脈寬約為764 ps,經(jīng)估算,KTP的有效拉曼增益系數(shù)為2.1 cm/GW。(8)、首次實(shí)現(xiàn)了W級(jí)Nd,MgO:LiNbO3晶體激光,并用獲得了1630 nm信號(hào)光。
[Abstract]:Since 1961, Franken et al use quartz crystal (Si02) to achieve frequency, success will be extended to the ruby laser ultraviolet band, the first time since the implementation of the frequency conversion of the true meaning of the subject, one of the nonlinear frequency conversion of laser science is within the scope of the most attractive. At present, the use of nonlinear optical crystal to realize frequency conversion technology is new the coherent light source is the most effective, most reliable and most common method. Two order nonlinear effect of nonlinear crystal (three wave interaction) and three order nonlinear effect (i.e. four wave interaction) have been widely studied. The depth and frequency conversion technology, frequency conversion technology, such as difference frequency, optical parametric process and stimulated Raman scattering, is the most potential gain in the infrared coherent light source. The single KTP crystal were used based on Q, Q and Q double double Wavelength laser as the pump source to achieve optical parametric oscillation and stimulated Raman scattering of two processes, and to establish a set of coupled rate equations, the experimental results are the theoretical simulation and analysis, the results showed that both are in good agreement; the use of a Kerr lens mode-locked and double loss modulation Q mode-locked laser as the pump for the first time. The optical parametric oscillator intracavity pumped mode-locked laser, the output pulse width in the sub nanosecond magnitude (Sub-nanosecond), and combined with the rate equation theory, establishes the theoretical model, numerical simulation and experimental results are basically identical; KTP is used for the first time as the Raman gain medium, using 1050 nm Yb:YAG laser as the pump, successfully obtained high order Stokes light output, pulse width is about 764 PS, estimated the effective gain coefficient of KTP; for the first time to achieve the level of W Nd MgO:LiNbO3 1094 sigma polarization, nm laser output, at the same time as the pump source, get KTP OPO 1630 nm signal light. The main research contents of this thesis are summarized as follows: (1) for the first time the graphene Q Nd, MgO:LiTaO31082 nm and 1092 nm dual wavelength laser operation, to obtain the maximum and minimum pulse width of 176 ns and 2.75 J pulse energy. (the first section of the second chapter () 2) for the first time to achieve a dual wavelength tunable Q mode-locked Nd:GGG laser, pulse width modulation depth of nearly 100%, is estimated to be 908 PS. (second: Second) (3) by using KTP crystal as multifunctional nonlinear crystal, while achieving the oscillation output of high order Stokes and OPO signal light. Up to 10.5 W when pumped at LD the maximum output power, signal waves up to 302mW, the minimum pulse width is only 1.61 ns, and the maximum power of two order and three order Stokes light is 115 mW, the minimum pulse width of 2.88 ns wavelength, respectively 1124.9 and 1160.7 nm. corresponding to the optical conversion efficiency is 2.88% 1.1%. and beam quality factor M2 in 1.2 . (third chapter) (4) for further compression of signal pulse width, double loss technology, which also use two kinds of saturated absorber, also won the OPO and SRS process, and the maximum power output signal wave is 208 mW, the pulse width is compressed to 580 PS, the peak power increased to 43.7 kW. KTP when adjusting the tilt angle, first observed wavenumber of 154 cm-1 frequency shift. (the third chapter) (5), Cr4+: YAG tunable Q Nd:LGGG laser as the pump source, to achieve a variety of nonlinear effects of dual wavelength pumping, namely SRS and OPO exist at the same time, the maximum signal light the power is 448 mW, the pulse width of 850 PS, peak power of signal light is as high as 30.6 kW, single pulse energy is 26 J, and the dual wavelength rate equations of this process were studied. (third: Second) (6), for the first time with LD pumped C cut Nd, MgO:LiNbO3 crystal. Won the 1.47 W The continuous laser output, this is the first time exceeded W output, compared to the previous reported increase of at least 20 times. With KTP crystal to achieve the OPO 1.63 M signal light operation, the pulse width is 1.69 ns, the peak power of 11.4 kW, compared with the previously reported increased 3 times (third: third). (7) for the first time, the Yb:YAG 1050 nm laser pumped KTP high order Raman light output, pulse width and pulse width of three order Stokes is about 764 PS. Stokes light is 1.54 ns, the peak power is 3.5kW. and beam quality in two directions were 1.64 and 1.48, indicating that Stokes, the fundamental frequency light and the anti Stokes the optical gain coefficient have good effective Raman collinear.KTP is estimated to be 2.1 cm/GW. (third: fourth) (8), for the first time of KLM laser pumped intracavity OPO, AOM selection of mode-locked pulse high peak power, respectively using Nd:GGG and Nd:YVO4 laser pumped KTP bonding, the successful completion of the high peak power, Subnanosecond 1.57 M wave output signal of high energy: the highest peak power of KLM Nd:GGG/KTP OPO signal is 102 kW, KLM Nd:YVO4/KTP OPO, the minimum pulse width of the signal wave is about 120 PS, combined with the rate equation simulation experimental results. (Fourth: first, second) (9), with AO and Cr4+: YAG the main passive double loss QML laser as the pump cavity OPO, and the V cavity, in the case of diode pumped 8.25 W, the modulation period of AO was fixed at 1 ms (i.e. the repetition rate is 1 kHz) obtained the highest output signal energy is 96 J, the envelope width is 2.5 ns. when the acoustooptic switch frequency at 5 kHz when the power signal wave output reaches the maximum, up to 156 mW, is currently the QML laser pumped intracavity OPO optical signal of the maximum power output. At the same time, the beam quality factor M2 signal by measuring less than 1.5. (the fifth chapter) (10), using AO and Cr4+. YAG The main passive double loss technology, won the first single clamping pulse KTP OPO, when the diode pumped 10.5 W acousto optic switch frequency is 2 kHz, the minimum pulse width of the signal wave is 450 PS, the peak power is up to 35.5 kW, and study the relationship between the output signal wavelength and temperature, it is found that the signal wave length temperature rises 0.027 nm/ degrees of blue shift rate. At the same time to establish a set based on the rate equations of QML mode-locked pump IOPO, by numerical simulation, the pulse waveform and output energy basically agree with the experimental value. (fifth: Second) a new main points of the thesis are as follows: (1) for the first time, the use of single block KTP crystal to achieve high order Stokes optical and optical parametric oscillation of two kinds of nonlinear process, the beam quality factor M2 in about 1.2. (2) for the first time, stimulated Raman scattering and optical parametric oscillation, the double modulated Q laser pumped light output pulse width signal. For the first time the degree of compression of 580 PS. (3), the first to achieve a variety of nonlinear frequency conversion process of dual wavelength laser pumped, and established a set of coupled rate equations, the theoretical results and experimental results. (4) for the first time, the intracavity OPO pumped by KLM laser operation, to achieve high peak power the signal light output. (5), the first implementation of the intracavity OPO active passive double loss modulated QML laser pumped, to obtain a stable output sub nanosecond signal. (6), for the first time success of the single mode-locked laser pumped OPO pulse signal, pulse width is about 450 PS, the fluctuation mechanism combining Q lock the laser mode, establish the corresponding model. (7), a 1150 nm Yb:YAG/KTP three order Stokes light output, pulse width is about 764 PS, it is estimated that the effective Raman gain coefficient of KTP is 2.1 cm/GW. (8), for the first time to achieve the level of W Nd, MgO:LiNbO3 laser, and obtained 1630 NM Signal light.

【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TN248
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本文編號(hào)：1520067