【摘要】：近年來,工作在人眼安全波段2μm波段的摻銩光纖激光器得到廣泛關注。其中2.05μm的激光位于大氣窗口,在大氣遙感,激光通訊領域有較大的應用前景。另外,該波長位于ZGP(ZnGeP2)晶體的低吸收波段,所以在中紅外光學參量振蕩器中也有著廣泛應用。本文主要開展了2.05μm波段高功率摻銩光纖激光器的研究,利用鎖模、聲光調制、增益開關等方法得到ps及ns級的種子源,并利用主振蕩功率放大系統分別獲得了高功率的ps、ns脈沖輸出和單頻連續及脈沖輸出。論文的主要內容包括:1、介紹了2.05μm光纖激光器的研究背景,根據輸出特性的不同,分別綜述了連續激光、超短脈沖、納秒脈沖輸出的光纖激光器的研究現狀。2、設計并實現了全光纖結構2050 nm高功率單頻連續及脈沖激光輸出的摻銩光纖激光器(TDFL)。使用分布式反饋(DFB)激光器作為整個系統的種子源,直接放大可以獲得最高75 W的單頻連續光輸出。對DFB放大后再用聲光調制器(AOM)進行調制可以獲得重復頻率脈寬均可調諧的單頻脈沖。以此為種子源經過放大后,最高可以獲得峰值功率大于0.6 kW的脈沖輸出,接近受激布里淵散射(SBS)閾值。3、設計并實現了全光纖結構2050 nm高峰值功率皮秒脈沖TDFL。自行搭建基于半導體飽和吸收鏡(SESAM)的鎖模激光器作為種子源,輸出脈寬約31.9 ps,重復頻率13.68 MHz。經過主振蕩功率放大(MOPA)系統的兩級放大器,平均功率被提升至23.5 W,對應峰值功率約為54 kW。4、設計并實現了全光纖結構2050 nm高能量納秒脈沖TDFL。實驗中采用增益開關技術搭建種子激光器,利用1550 nm脈沖激光做為泵浦源,直接獲得重復頻率可調、脈沖寬度可控的納秒脈沖輸出。通過MOPA系統對納秒脈沖進行放大,并對放大器進行細節上的優化,首次在全光纖結構中實現單個脈沖能量1 mJ,峰值功率10 kW的納秒脈沖輸出。實驗中還研究了不同重復頻率的1550 nm激光泵浦時,增益開關激光器的輸出特性。結果表明,泵浦光重復頻率越高,激光器的平均功率閾值越高,且輸出脈沖寬度越窄。
[Abstract]:In recent years, thulium doped fiber lasers working in the 2 渭 m band of human eye safety have received wide attention. The 2.05 渭 m laser is located in the atmospheric window, which has a great application prospect in the field of atmospheric remote sensing and laser communication. In addition, the wavelength is located in the low absorption band of ZGP (ZnGeP2) crystal, so it is widely used in the middle infrared optical parametric oscillator. In this paper, the research of 2.05 渭 m high power thulium doped fiber laser is carried out. The seed sources of ps and ns are obtained by mode-locking, acousto-optic modulation and gain switch, respectively, and the high power ps, is obtained by using the main oscillatory power amplifier system. Ns pulse output and single frequency continuous and pulse output. The main contents of this paper are as follows: 1. The research background of 2.05 渭 m fiber laser is introduced. According to the different output characteristics, the research status of fiber laser with continuous laser, ultrashort pulse and nanosecond pulse is summarized respectively. An all-fiber structure 2050 nm high power single frequency CW and pulse laser output thulium doped fiber laser (TDFL). Is designed and implemented. The distributed feedback (DFB) laser is used as the seed source of the whole system, and the single frequency CW output of 75 W can be obtained by direct amplification. The single frequency pulse with tunable pulse width can be obtained by modulating the DFB with the acoustooptic modulator (AOM). When the seed source is amplified, the pulse output with peak power greater than 0.6 kW can be obtained, which is close to the stimulated Brillouin scattering (SBS) threshold. 3. An all-fiber structure of 2050 nm high peak power picosecond pulse TDFL. is designed and implemented. A mode-locked laser based on semiconductor saturable absorption mirror (SESAM) was built as seed source. The output pulse width is about 31.9 ps, repetition rate 13.68 MHz.. Through a two-stage amplifier of (MOPA) system with main oscillatory power amplifier, the average power is raised to 23.5 W, and the corresponding peak power is about 54 kW.4,. An all-fiber structure of 2050 nm high energy nanosecond pulse TDFL. is designed and realized. In the experiment, the gain switch technique is used to construct the seed laser, and the 1550 nm pulse laser is used as the pumping source. The nanosecond pulse output with adjustable repetition rate and controllable pulse width is obtained directly. The nanosecond pulse is amplified by the MOPA system, and the amplifier is optimized in detail. It is the first time to realize the nanosecond pulse output of a single pulse energy of 1 mJ, peak power of 10 kW in the all-fiber structure. The output characteristics of the gain-switched laser pumped by 1550 nm laser with different repetition rate are also studied. The results show that the higher the pump repetition rate, the higher the average power threshold and the narrower the output pulse width.
【學位授予單位】：國防科學技術大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN248

【參考文獻】

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1 韓隆;苑利鋼;陳國;候天禹;魏磊;何利杰;王克強;;26W中波紅外固體激光器[J];中國激光;2015年03期

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本文編號：2377690