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1.
主动锁模掺饵光纤环形激光器有理数谐波调制技术   总被引:1,自引:0,他引:1       下载免费PDF全文
王林  于晋龙 《物理学报》1999,48(5):876-881
成功地利用有理数谐波锁模技术在主动谐波锁模掺饵光纤环形激光器中获九倍于调制频率fm的高重复率脉冲序列,所得最高锁模脉冲重复频率fp=4f≈6GHz。根据实验结果,本文指出有理数谐波锁模输出高阶光脉冲的物理机制、导致高阶输出脉冲脉宽展宽和幅度不稳定的原因以及消除幅度不稳定的具体办法。  相似文献   

2.
 为了实现高重复频率和高功率的光脉冲,实验采用Er3+/Yb3+共掺双包层光纤作为增益介质,稳定的中心波长为976 nm的高功率半导体激光器作为泵浦源,利用非线性偏振旋转锁模技术,得到稳定的自起振锁模光脉冲。当泵浦功率为2.4 W时,激光器输出重复频率为8.829 MHz的连续锁模光脉冲,平均输出功率为52.5 mW,自起振锁模泵浦阈值功率为0.6 W,并观测到了稳定的高阶谐波锁模、调Q和调Q-锁模光脉冲输出。  相似文献   

3.
王林  李景镇  徐平 《光学学报》2001,21(5):67-570
在理论上详细分析了利用非线性光学环形镜(NOLM)来减小输出脉冲幅度波动,消除噪声并对脉冲进行压缩整形的物理机制。在主动锁模掺铒光纤环形激光器中(AHML-EDFL)接入一个非线性光学环形镜,形成结构新颖的主被动锁模掺铒光纤激光器(APHML-EDFL),利用非线性光学环形镜所具有的饱和吸收体功能,成功地制抑了4阶有理数谐波锁模(RHML)中较大的幅度噪声,在1GHz量级的调制频率下,由主被动锁模掺铒光纤激光器获产生重复频率为5.1GHz,幅度相当稳定的4阶有理数谐波锁模脉冲序列。  相似文献   

4.
提出并分析验证了一种利用有源环形滤波器对有理数谐波锁模激光器输出光脉冲幅度进行均衡的方案。方案中,光纤结构的有源环形滤波器被视为一个自由光谱范围可调谐的梳状滤波器,使有理数谐波锁模激光器输出光脉冲中的锁模分量通过而其他谐波分量和超模得到抑制,获得幅度均衡的光脉冲。理论上,对经过有源环形滤波器前后光脉冲的波形和频谱分别进行了仿真,结果表明有源环形滤波器能有效滤出所需的锁模频率,且Q值越高,光脉冲的幅度均衡效果越佳。在7阶、11阶、14阶有理数谐波锁模条件下通过实验进行验证,均获得了良好的效果,模式抑制比可提高20 d B以上。  相似文献   

5.
8字形主被动锁模掺Er3+光纤激光器   总被引:6,自引:0,他引:6  
在理论上分析了利用非线性光学环形镜作为等效可饱和吸收体压缩脉冲进行锁模的物理机制。利用8字形主被动混合锁模的结构在调制频率2.498749GHz下,在1.543μm处获得了12ps的锁模脉冲输出,对应谱宽0.22nm,时间脉宽积0.33。在抽运功率50mW情况下,输出脉冲平均功率3.715mW。在调制频率2.499344GHz、2.499114GHz和2.498999GHz时分别并获得了2~4阶幅度较为均衡的有理数谐波锁模脉冲序列。  相似文献   

6.
被动谐波锁模掺Yb3+光纤环形激光器   总被引:2,自引:2,他引:2       下载免费PDF全文
 利用光纤的非线性偏振旋转效应产生可饱和吸收体的锁模机制,从掺Yb3+光纤环形激光器中得到稳定高阶谐波锁模光脉冲。理论分析了工作于正色散区的掺Yb3+光纤环形激光器的特性。实验中观测到了掺Yb3+光纤环形激光器3种不同演化方式产生高阶锁模光脉冲。4阶谐波锁模脉冲(107.2 MHz重复频率)经过1 m长高掺杂Yb3+光纤放大器放大后产生了平均功率100 mW,脉宽22.8 ps的脉冲,最后经过光栅压缩得到了平均输出功率20 mW,脉宽307 fs,脉冲中心波长1 051.2 nm,带宽13.76 nm的激光。  相似文献   

7.
LD调制有理数谐波锁模光纤激光器   总被引:1,自引:1,他引:0  
本文将F-PLD与环形光纤激光器结合起来,以LD作为调制器,得到高稳定单波长超短光脉冲序列.与工作在增益开关状态的LD相比,平均输出功率提高到2mW,脉冲宽度压窄到47ps.并利用有理数谐波锁模技术,得到重复频率5GHz(5阶有理数谐波锁模)的锁模脉冲,脉冲宽度略有展宽为49ps.  相似文献   

8.
 报道了Er3+-Yb3+共掺杂光纤作为增益介质的环型腔光纤激光器。利用光纤的非线性偏振旋转效应产生可饱和吸收体的锁模机制,通过调整泵浦功率,调节偏振控制器的状态,实现了连续基波锁模和高阶谐波锁模两种稳定的锁模运转状态。其中连续基波锁模重复频率15.89 MHz,中心波长为1.557 nm,光谱宽度为9.9 nm。二阶谐波锁模重复率为31.79 MHz,三阶谐波锁模脉冲重复率为46.99 MHz。观察到了调Q锁模和调Q脉冲序列,给出了各种运转状态的实验结果并对多种锁模机理作了简要的分析。  相似文献   

9.
报道了利用光纤的非线性偏振旋转效应产生可饱和吸收体的锁模机制,从掺Er3+光纤环形腔激光器中产生稳定的高阶谐波锁模光脉冲的实验研究结果(限于示波器带宽,实验中最高曾测量到稳定的4076MHz重复频率的谐波锁模光脉冲).实验中发现有三种不同的演化方式产生高阶谐波锁模光脉冲,还观察到在8352MHz谐波锁模光脉冲的光谱中出现孤子光谱边带.四阶谐波锁模(8352MHz重复频率)超短光脉冲经过6m长高掺杂浓度的掺Er3+光纤放大器放大后产生了平均输出功率1388mW,脉宽201fs,中心波长1531μm,单脉冲能 关键词:  相似文献   

10.
基于色散不对称光纤环形镜的锁模光纤激光器   总被引:1,自引:0,他引:1  
在理论上数值计算了各种常量对色散不对称非线性光纤环形镜透射特性的影响。并分析了它作为被动锁模器件用于光纤激光器压窄脉冲的物理机制。利用8字形主被动混合锁模的结构在调制频率为9.998748700 GHz,波长为1566.65nm处获得了11ps的稳定锁模脉冲输出.对应谱宽0.297nm.同时在重复频率为9.995792825 GHz和9.996778256 GHz时分别得到了振幅均匀的二阶和三阶谐波锁模输出。证明色散不对称非线性光纤环形镜可以有效消减脉冲的尾翼和噪声.得到脉幅稳定的脉冲序列。  相似文献   

11.
M Yan  W Li  K Yang  D Bai  J Zhao  X Shen  Q Ru  H Zeng 《Optics letters》2012,37(15):3021-3023
We experimentally explored the influence of passive harmonic mode locking on the temporal and spectral features of a ytterbium-doped fiber laser. Similar dependences of free-running linewidth of the laser carrier-envelope offset frequency (f0) on the intracavity net dispersion were observed for the fundamental-, second-, and third-order mode-locking states. Due to the reduction of nonlinear effects and supermode phase locking that balanced the third-order dispersion in the fiber cavity, the third-order harmonic mode-locking exhibited the narrowest free-running f0linewidth of ~120 kHz in the near-zero net dispersion regime.  相似文献   

12.
Simultaneous Q-switching and mode-locking in a laser-diode end-pumped intracavity frequency doubled Nd:YVO4/KTP green laser using Cr4+:YAG saturable absorber is experimentally demonstrated. The influence of the initial transmission (T0) of the Cr4+:YAG crystal on the Q-switched mode-locked green pulses as well as on the average green power is characterized by using Cr4+:YAG crystal with various T0. The effect of T0 on the pulse build-up time in intracavity second harmonic configuration is theoretically investigated. It was found that the depth of modulation for the mode-locked pulses is greatly improved at the second harmonic wavelength as compared to that for the fundamental wavelength. The average pulse duration of the individual mode-locked pulse for the second harmonic beam measured to be less than 500 ps with a repetition rate of 400 MHz.  相似文献   

13.
In this paper we report passive harmonic mode-locking of an Erbium/Ytterbium-doped double-clad fiber laser with repetition rates up to 10 GHz. The modes synchronization was obtained using Nonlinear Polarization Rotation mechanism. The stable operation at 634th harmonic of the fundamental (15.8 MHz) repetition frequency was achieved. Soliton pulses with the duration of less than 900 fs and 300 mW average output power were obtained.  相似文献   

14.
Construction details and operating characteristics are reported for a pulsed dye laser oscillator followed by a three-stage dye laser amplifier. The system is excited with 220 mJ of the second or120 mJ of the third harmonic radiation of a Nd-YAG laser. With Rhodamine dyes the output energy exceeds 55 mJ (9 MW peak power). Coumarin dyes provide pulses of more than 15 mJ (3 MW). Spectral narrowing to less than 260 MHz or 2.7 × 10 -4 nm at 565 nm is achieved by a single intracavity etalon of 37.5 GHz free spectral range. Gas pressure tuning allows a continuous linear variation of the laser frequency over more than 3.9 × 103 GHz (4 nm at 565 nm). The frequency doubled laser output provides tunable UV light of narrow bandwidth (1.4 × 10-4 nm) and of peak powers exceeding 3 MW.  相似文献   

15.
Optical clock division and multiplication were realized with an injection mode-locked fiber ring laser based on semiconductor optical amplifier SOA owing to the relatively long recovery time of carriers in SOA and the rational harmonic mode-locking. Second frequency division and 1.5th frequency multiplication of 10 GHz, second and th frequency division of 20 GHz optical pulse trains were realized, respectively, in the experiment.  相似文献   

16.
In conventional rational harmonic mode-locking, optical pulse trains with the repetition rate of(pn + 1)fc are generated when the modulation frequency of the in-cavity modulator is set at fm=(n + 1/p)fc, where n and p are both integers, fc is the fundamental cavity frequency. In this paper, we report that rational harmonic mode locking phenomenon takes place in the fiber lasers when the modulation frequency is set at fm =(n + 2/p)fc. The pulse generations are experimentally demonstrated when the numerator of the rational corresponds to 2 in 5th and 7th order rational harmonic mode-locking.  相似文献   

17.
A novel passively gigahertz harmonic mode-locked all-fiber laser based on hybrid fiber structure (single-mode fiber–graded-index multimode fiber–single-mode fiber (SMS)) is proposed SMS, which coils on the paddles of polarization controller (PC), is demonstrated to modulate the temporal intensity for mode-locking. The nonlinear absorption properties of the optical switch are controllable by adjusting the paddles of PC; such an ultrafast optical switch enables the wavelength switchable harmonic mode-locking operation. Ultrafast pulses with 1.9 ps at 1558.41 nm and 0.95 ps at 1563.08 nm are generated. The maximum repetition rate of the laser up to 1.127 GHz harmonic of fundamental repetition mode-locking at 1563.08 nm, corresponding to 880 order, and the output power is 4.2 mW. Considering its superiority in terms of low cost, easy integration, and high reliability, the findings validate that SMS can be used in harmonic mode-locking.  相似文献   

18.
Efficient infrared varactor mixing near 9 μm has been performed between diode-laser and CO2 laser. Difference frequency up to 17 GHz has been detected using non linear mixing between the two radiations and the first four harmonics of a microwave frequency (f = 4.2 GHz). As a result, the absorption spectrum of ozone near the 9R6 CO2 line is frequency scaled over a 1.7 cm-1 range with microwave accuracy.  相似文献   

19.
This paper describes the basic principles and the set up of a new kind of frequency halvers suited for millimeter wave applications. A Ga As Gunn-device is used to act like a nonostable multivibrator having a hold time adequate to the domain transit time Tt of the Gunn-device.In a certain frequency range depending on the transit frequency fT=1/TT, bias voltage and circuit parameters a harmonic wave synchronized fundamental/2nd harnonic mode oscillator is able to perform as a frequency halver. An input power of only 1mW is sufficient to achieve a bandwidth of 5 GHz respectively 2.5 GHz centered around 94 GHz respectively 47GHz. Since the output power is 50 mW at fundamental frequency fF, this halver offers 17dB conversion gain.  相似文献   

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