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Chirped pulse amplification with a nonlinearly chirped fiber Bragg grating matched to the Treacy compressor 总被引:1,自引:0,他引:1
We demonstrate a fiber chirped pulse amplification system that uses an engineered nonlinearly chirped fiber Bragg grating stretcher dispersion matched to the Treacy compressor. The seed pulses at 1558 nm are stretched to 720 ps, amplified by more than 50 dB to 6.5-microJ energy, and recompressed to 940 fs. After almost 1000 times compression the pulses are within 30% of the bandwidth limit and have a contrast ratio of better than 30 dB. 相似文献
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Fourier-domain low-coherence interferometry for differential mode delay analysis of an optical fiber
We propose a novel mode analysis and differential mode delay measurement method for an optical fiber using Fourier-domain low-coherence interferometry. A spectral interferometer based on a Mach-Zehnder interferometer setup was used with a broadband source and an optical spectrum analyzer to detect relative temporal delays between the guided modes of a few-mode optical fiber by analyzing spectral interference signals. We have shown that experimental results of the proposed method agree well with those results obtained by using a conventional time-domain measurement method. We have demonstrated that this new mode analysis technique has high sensitivity (<60 dB) and very good resolution (<1 ps/m). 相似文献
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In this paper, we present a theoretical calculation of a highly nonlinear germanium (Ge) doped photonic crystal fiber with all-normal group velocity dispersion to design a supercontinuum (SC) light source at 1.55 μm. By doping 3% higher refractive index Ge inside the host silica, the nonlinear coefficient is increased to a value as large as 60.5 W?1 km?1 at 1.55 μm. A 10 dB bandwidth of a 120 nm SC spectrum for a 2.5 ps input optical pulse and a 10 dB bandwidth of a 190 nm SC spectrum for a 1.0 ps input optical pulse have been found using the same fiber length of 200m and input optical power of 18 W. The coherent lengths of the generated SC light sources are found to be 8.8 μm for a 2.5 ps input optical pulse and 5.6 μm for a 1.0 ps input optical pulse. Therefore, the highest longitudinal resolution at 1.55 μm is found to be about 4.0 μm for biological tissues. 相似文献
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A stationary rescaled pulse (SRP) exists in a dispersion-managed comblike profiled fiber (DM-CPF) that consists of alternate concatenations of normal-dispersion highly nonlinear fiber and single-mode fiber. Numerical analysis reveals that the newly found SRP exhibits a nearly Gaussian temporal profile with a small amount of pedestal in spite of a relatively large compression ratio. We apply the SRP propagation to optical pulse compression based on DM-CPF and demonstrate highly efficient and high-quality optical pulse compression. Using a three-step DM-CPF, we experimentally show that a 2.6 ps width input pulse is successfully compressed to a nearly Gaussian pulse having the width of 0.39 ps and the peak-to-pedestal ratio of 19.3 dB. 相似文献
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提出了一种以处于增益开关调制状态下的法布里珀罗(Fabry-Pérot)半导体激光器作为光源,采用简单的自激注入锁定方式,以生成波长可调谐的超短光脉冲的实验系统。该实验装置中,激光器的外腔包括两个串联在一起的布拉格光纤光栅,一个掺铒光纤放大器(EDFA),一个光耦合器和两个环行器,其作用是选模,以及增强并控制反馈回激光器内腔的光强。该实验系统简单而高效,在24nm的波长调谐范围内获得了边模抑制比高于40dB的单模光脉冲输出;而在1521.8nm和1550.0nm之间28.2nm的波长调谐范围内,边模抑制比高于35dB。所得到的各个单波长激光脉冲的时域半峰全宽为140~260ps,各个脉冲的光谱半峰全宽皆为0.1nm。 相似文献
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The spectral density of the phase noise of an optical pulse in a fiber produced by guided acoustic wave Brillouin scattering (GAWBS) is derived from first principles. The predictions are in good agreement with the experimental results in a fiber interferometer. The experiments show that the lower limit on the quantum noise reduction is set by GAWBS. The GAWBS are of sufficiently low level to permit 5 dB squeezing. 相似文献
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针对大容量光纤通信系统,设计了一种实用化的椭圆纯硅芯少模光纤,给出了光纤的设计原理与参考标准,运用全矢量有限元法结合完美匹配层边界条件分析了光纤的传输特性.在1.4~1.65μm波长处,光纤处于稳定的HE_(11)和HE_(21)双模运转,模式有效折射率差大于1.8×10~(-3),避免了模间耦合和串扰;在工作波长1.55μm处,HE_(11)和HE_(21)模的色散系数分别为19.61和4.41ps/(nm·km),色散斜率分别为0.048和0.002ps/(nm~2·km),模场面积分别为97.17和143.96μm2,模式的衰减系数均小于0.21dB/km.该光纤的传输特性基本符合G.652和G.655光纤标准,可利用现有成熟的"预制棒拉丝工艺"制备,同时与波分复用技术相结合可以成倍提升光网络的传输容量,对于下一代通信网络带宽的提升具有重要意义. 相似文献
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A backward dark-optical-comb-injection mode-locked semiconductor optical amplifier fiber laser (SOAFL) with a femtosecond pulse width and an ultrahigh supermode-noise suppressing ratio (SMSR) is primarily demonstrated. The mode-locked SOAFL pulse with a spectral linewidth of 0.45 nm is shortened from 15 to 8.6 ps under chirp compensation in a 420 m long dispersion-compensated fiber, corresponding to a time-bandwidth product of 0.48. The eighth-order soliton is obtained by the nonlinearly soliton's compression of the chirp-compensated SOAFL pulse in a 112 m long single-mode fiber at an input peak power of 51 W, providing the pulse width, the linewidth, and the nearly transform-limited time-bandwidth product are <200 fs, 13.8 nm, and 0.34, respectively. The phase noise and integrated timing jitter at an offset frequency below 1 MHz are -105 dBc/Hz and 0.8 ps, respectively. An ultrahigh pulse-compression ratio of 43 and a SMSR of 87 dB for the eighth-order SOAFL soliton are reported. 相似文献
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The efficient generation of a 1.17-mJ laser pulse with 360 ps duration using an ytterbium (Yb)-doped fiber amplifier chain seeded by a homemade mode-locked fiber laser is demonstrated experimentally.A specially designed figure-of-eight fiber laser acts as the seed source of a chirped-pulse amplification (CPA) system and generates mode-locked pulses with hundreds of picosecond widths.Two kinds of large-mode-area (LMA) double-clad Yb-doped fibers are employed to construct the pre-amplifier and main amplifier.All of the adopted instruments help avoid severe nonlinearity in fibers to raise sub-nanosecond pulse energy with acceptable signal-to-noise ratio (SNR).The output spectrum of this fiber-based CPA system shows that amplified spontaneous emission (ASE) is suppressed to better than 30 dB,and the onset of stimulated Raman scattering is excluded. 相似文献
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High-dispersive mirror for pulse stretcher in femtosecond fiber laser amplification system 下载免费PDF全文
Wenjia Yuan 《中国物理 B》2022,31(8):87801-087801
We present a high-dispersive multilayer mirror for pulse stretching in a femtosecond fiber laser amplification system. The designed mirror contains 54 layers with a total physical thickness of 7.3 μm, which can provide a positive group delay dispersion (GDD) of 600 fs2 and a high reflectance over 99.9% from 1010 to 1070 nm. The samples were prepared by dual ion beam sputtering. The measured transmittance matches well with the theoretical result. The GDD characteristics of samples were tested by home-made white light interferometer. The measured GDD is higher than the design results, an average GDD of +722 fs2 from 1010 nm to 1070 nm. The mirrors were employed in a Yb-doped large-mode-area photonic crystal fiber amplification system. An input pulse compressed by the gratings with autocorrelation function of 83 fs is obtained with a stretched FWHM of 1.29 ps after 28 bounces between the dispersive mirrors. The results show that the multilayer dispersive mirror could be an effective and promising technique for pulse stretching in femtosecond amplification systems. 相似文献
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A highly stable erbium-doped fiber (EDF) ring laser with broad tunability is proposed and experimentally demonstrated. It is accomplished by using a few-mode polarization maintaining fiber (FM-PMF) Sagnac interferometer, in which simultaneous Sagnac and modal interferences occur. Continuously tunable output is obtained by exerting the longitudinal strain on the FM-PMF in combination with adjusting a polarization controller (PC) next to the FM-PMF in the Sagnac interferometer. In addition, the adverse impact of uneven EDF gain distribution on the laser output power uniformity may be offset by the PC-dependent transmission loss of the FM-PMF Sagnac interferometer and reflected backward C-band amplifier spontaneous emission from the pumped EDF. During the whole tuning process, the tunable span covers more than 40 nm with the output power flatness better than 1 dB, 3 dB spectral linewidth narrower than 0.1 nm and optical signal-to-noise extinction ratio higher than 45 dB. 相似文献
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Fei Wang 《Optics & Laser Technology》2011,43(4):848-851
A stable multiwavelength mode-locked semiconductor fiber ring laser incorporating a fiber Mach-Zehnder interferometer (MZI) filter was proposed and experimentally demonstrated. A semiconductor optical amplifier (SOA) serves as an optically controlled mode-locking element due to gain exhaustion caused by external injected optical pulses. Another SOA severs as a constant-gain medium. A fiber MZI filter with a temperature control is incorporated into the fiber ring cavity to acquire a stable and tunable multiwavelength oscillation. Twelve wavelengths are synchronously mode-locked at 10 GHz, pulse width of mode-locked pulse are about 30 ps. Proposed multiwavelength mode-locked semiconductor fiber ring laser has some distinct advantages, such as simple and compact structure, easy integration, convenient tuning, good stability, potential high repetition rate operating, which has potential application in the future WDM communication system. 相似文献
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根据超短光脉冲在光纤中传输的非线性薛定谔方程,模拟了不同色散参量情况下色散补偿和色散位移光纤对增益开关半导体激光器产生的光脉冲的压缩,给出了光脉冲在经过色散补偿光纤前后的啁啾曲线。结果表明,使用色散参量D分别为-150,-180和-20ps/(nm·km)的色散补偿光纤可以实现其他脉冲压缩方法的压缩效果,最大压缩因子达到6.09,但色散参量越大,所需光纤长度就越短。此外,脉冲经过色散补偿光纤后线性啁啾几乎为零。还利用色散位移光纤对脉冲进行孤子压缩,脉冲宽度由最初的45ps减小到1.23ps。指出采用这2种光纤相结合的方法可以对光脉冲实现高效压缩。 相似文献
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Wideband All-Polarization-Maintaining Yb-Doped Mode-Locked Fiber Laser Using a Nonlinear Optical Loop Mirror 下载免费PDF全文
《中国物理快报》2016,(5)
We report on a wide-band and stable mode-locked all-polarization-maintaining fiber iaser configuration using a noniinear optical loop mirror.The central wavelength of the laser is 1080.14 nm and the 3dB bandwidth is 20.29 nm.The repetition rate of the pulse is 3.28 MHz and the pulse width is 848 ps.By tuning the pump power,which is centered at 980 nm,from 300 mW to 380 mW,we obtain a linearly changed output power from 6mW to 7.12 mW.The all-polarization-maintaining fiber configuration is fundamental to the stability of the output power. 相似文献
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By operating an intracavity semiconductor-optical-amplifier- (SOA-) based high-pass filter at the nearly transparent current condition, the supermode noise (SMN), the relaxation oscillation, and the single-sideband (SSB) phase noise can be simultaneously suppressed in an actively mode-locked erbium-doped fiber laser (EDFL). The SOA at the nearly transparent condition enhances the SMN suppression ratio of the EDFL from 32 to 76 dB at the cost of the phase noise degrading from -114 to -104.2 dBc/Hz and broadening the pulse width from 36 to 61 ps. With an optical bandpass filter, the SSB phase noise and the SMN suppression ratio can be further improved to -110 dBc/Hz and 81 dB, respectively. The EDFL pulse can be further shortened to 3.1 ps with a time-bandwidth product of 0.63 after compression. 相似文献