Optics express最新文献_第6页

Focal spot diagnostic of pulsed planar anticathode accelerator with compressed streak imaging. 脉冲平面反阴极加速器的压缩条纹成像焦斑诊断。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.558974

Zhiming Yao, Liang Sheng, Yan Song, Haoyu Zhou, Zhen Liu, Chao Ji, Changcai Han, Baojun Duan, Yang Li, Weipeng Yan, Jiming Ma, Chengzhi Jin, Dalong Qi, Shian Zhang

{"title":"Focal spot diagnostic of pulsed planar anticathode accelerator with compressed streak imaging.","authors":"Zhiming Yao, Liang Sheng, Yan Song, Haoyu Zhou, Zhen Liu, Chao Ji, Changcai Han, Baojun Duan, Yang Li, Weipeng Yan, Jiming Ma, Chengzhi Jin, Dalong Qi, Shian Zhang","doi":"10.1364/OE.558974","DOIUrl":"https://doi.org/10.1364/OE.558974","url":null,"abstract":"The spatial-temporal distribution of the focal spot is a key characteristic for evaluating a pulsed accelerator. However, the small number of frames and the low frame frequency limit the accurate analysis of the focal spot evolution process in a single shot. Compressed ultrafast photography (CUP) has recently demonstrated the ability of capturing 980 frames at 7 × 1013 fps with a single camera snapshot. In this paper, we demonstrate the utilization of compressed sensing for focal spot diagnostic of a pulsed planar anticathode accelerator called \"Chenguang\". In particular, our system incorporates a large-format streak camera, an ICCD camera and a PIN detector. The traditional pinhole imaging method is discarded for its low X-ray projection efficiency. Instead, a scintillator is placed close to the anticathode and converts the X-ray focal spot image to visible light image directly. Different reconstruction strategies, including the deep prior denoising algorithm, have been tried to verify the accuracy of the reconstruction results with each other. The two-dimensional time series images of the focal spot of \"Chenguang\" in strongly-pinched and weakly-pinched modes are observed for the first time. The detailed evolution process of the X-ray focal spot is revealed.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 7","pages":"15551-15560"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144018451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the spectral characteristics of IF signals and its influence on the performance of heterodyne Φ-OTDR. 中频信号的频谱特性及其对外差性能的影响研究Φ-OTDR。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.559338

Chi Zhang, Chengzhen Luo, Xiyuan Zhang, Shaoxiong Tang, Chenyang Ding, Imtiaz Naseeb Awan, Shuai Tong, Hao Ding, Tian Xiao, Ningmu Zou, Yixin Zhang, Xuping Zhang

{"title":"Study on the spectral characteristics of IF signals and its influence on the performance of heterodyne Φ-OTDR.","authors":"Chi Zhang, Chengzhen Luo, Xiyuan Zhang, Shaoxiong Tang, Chenyang Ding, Imtiaz Naseeb Awan, Shuai Tong, Hao Ding, Tian Xiao, Ningmu Zou, Yixin Zhang, Xuping Zhang","doi":"10.1364/OE.559338","DOIUrl":"https://doi.org/10.1364/OE.559338","url":null,"abstract":"The heterodyne phase-sensitive optical time-domain reflectometer (Φ-OTDR) is one of the most popular distributed optical fiber sensing (DOFS) technologies due to its high sensitivity, wide frequency response bandwidth, large dynamic range, and resistance to electromagnetic interference. In the signal processing workflow, like the I/Q algorithm, digital filtering of intermediate frequency (IF) signals is unavoidable. This study combines the advantages of the scattering point superposition model and the phase-modulated signal model. Three methods for quasi-matched IF filters are proposed. A signal evaluation system combining Parseval signal-to-noise ratio (Pa-SNR), peak-to-peak value, and signal-to-noise ratio (SNR) is employed. For CIC-type IF filters, it is recommended to cascade no more than 3 low-tap filters. For the variant CIC filter, its demodulation rate is faster than that of the other two filters. But resulted in an SNR of 10 dB lower than the CIC filter, and 15 dB lower than FIR filters because of the asymmetry of IF signals we demonstrated. For FIR-type IF filters, we recommend that the passband cutoff frequency should be at least 2.43 times the reciprocal of the pulse width. This factor decreases with increasing pulse width and narrowing of the transition band, but should not be lower than 1.08. Additionally, it is important to note that within approximately 0.8 times the transition band range of the cutoff frequency, half of the demodulation performance may degrade due to the IF filter passband ripple characteristics.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 7","pages":"16389-16407"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144040121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Method for expanding the field-of-view of micro-CT imaging using array micro-focus X-ray source. 阵列微聚焦x射线源扩展微ct成像视场的方法。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.547315

Guowei Zhong, Fengxiao Li, Haijun Yu, Chengfeng Liu, Run Yang, Rifeng Zhou

{"title":"Method for expanding the field-of-view of micro-CT imaging using array micro-focus X-ray source.","authors":"Guowei Zhong, Fengxiao Li, Haijun Yu, Chengfeng Liu, Run Yang, Rifeng Zhou","doi":"10.1364/OE.547315","DOIUrl":"https://doi.org/10.1364/OE.547315","url":null,"abstract":"Micro-computed tomography (micro-CT) is a critical high-resolution, non-destructive testing technique. However, its field-of-view (FOV) is constrained by the detector size, which limits the ability to perform high-resolution imaging of larger objects. To overcome this limitation, we developed a method for expanding the FOV of micro-CT imaging using an array micro-focus X-ray source based on electron beam scanning (EBMCT). This innovative approach expands the FOV by allowing X-rays to traverse different regions of the object through focal array scanning. Due to the unique scanning methodology of EBMCT, the resulting projections exhibits redundancy and truncation issues. For this reason, we propose a weighting distribution strategy based on trigonometric functions to smooth the projections, effectively mitigating the effects of redundancy and truncation on the reconstructed images. Furthermore, by combining the geometric structure of EBMCT and the weighting function, we derive a two-dimensional analytical reconstruction algorithm (Weighted multi-sources filtering back-projection, w-MSFBP) and a three-dimensional approximate reconstruction algorithm (Weighted multi-sources Feldkamp-Davis-Kress, w-MSFDK) for EBMCT reconstruction. Simulation and physical experiment results show that EBMCT can expand the FOV by more than two times while maintaining high resolution. Additionally, both the w-MSFBP and w-MSFDK algorithms accurately reconstruct two-dimensional and three-dimensional structures of the scanned objects. By effectively expanding the FOV of micro-CT, EBMCT provides valuable insights for the research and design of large FOV micro-CT systems.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 7","pages":"16141-16160"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144064112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chirp-free hundred-picosecond pulse fiber laser based on carbon nanotubes mode-locker. 基于碳纳米管锁模器的无啁啾百皮秒脉冲光纤激光器。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.555670

Weixi Li, Kailin Jiang, Lilong Dai, Qianqian Huang, Meng Zou, Siyu Luo, Siyu Chen, Yingxiong Song, Yunqi Liu, Zhijun Yan, Chengbo Mou

{"title":"Chirp-free hundred-picosecond pulse fiber laser based on carbon nanotubes mode-locker.","authors":"Weixi Li, Kailin Jiang, Lilong Dai, Qianqian Huang, Meng Zou, Siyu Luo, Siyu Chen, Yingxiong Song, Yunqi Liu, Zhijun Yan, Chengbo Mou","doi":"10.1364/OE.555670","DOIUrl":"https://doi.org/10.1364/OE.555670","url":null,"abstract":"We demonstrate a narrow bandwidth passively erbium-doped mode-locked fiber laser based on single-wall carbon nanotubes (SWCNTs). The center wavelength is 1546.61 nm. The strong filtering effect and low saturable absorber (SA) modulation depth provide advantages for a long pulse duration of 323 ps. An overall spectral bandwidth of 1.3 GHz (0.01 nm) is measured by the optical heterodyne method, representing the narrowest spectral width based on SWCNT under a single filter structure. The obtained spectral width is very close to the transform-limited bandwidth of 8 pm, indicating that the pulse is chirp-free. Meanwhile, the generation of beat signals reveals the strong coherence between pulses. The repetition frequency of the laser is 7.8 MHz, and the number of longitudinal mode locks is only 166, which is the minimum number of longitudinal mode-locking in passively mode-locked laser based on material SA. At the same time, numerical simulations further support our experimental results and reveal the pulse evolution, providing evidence that SA and filter are the key factors in the generation of chirp-free long pulse.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 7","pages":"14850-14857"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144063829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Speckle effects on time-of-flight estimation of lidar pulses. 激光雷达脉冲飞行时间估计中的散斑效应。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.557376

Jeffrey R Chen, Guangning Yang, Mark A Stephen, Hui Li

引用次数: 0

Buffer gas enhancing of power conversion efficiency of a continuous-wave acetylene-filled fiber gas laser at the 3 μm wavelength. 缓冲气体增强3 μm波长连续波乙炔填充光纤气体激光器的功率转换效率。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.558895

Zhuo Chen, Yunfu Li, Xinyue Zhu, Lili Hu, Meng Wang, Du Wang, Fei Yu

引用次数: 0

Shaping ultrafast Bessel-like beamlets for single-pass laser chamfering of glass. 用于玻璃单次激光倒角的超快类贝塞尔光束成形。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.547468

Craig Ungaro, Lauren L Taylor, Zheng Xiong, Garrett A Piech

引用次数: 0

Double-Stokes characterization of depolarized light using two-photon excited fluorescence. 双光子激发荧光去偏振光的双斯托克斯表征。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.557145

Charles W Stark, Ida Pinte, Meelis-Mait Sildoja, Juri Pahapill, Aleksander Rebane

引用次数: 0

Spectroscopy and SESAM mode-locking of a disordered Yb:Gd₂SrAl₂O₇ crystal. 无序Yb:Gd2SrAl2O7晶体的光谱学和SESAM模式锁定。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.559152

Huang-Jun Zeng, Zhang-Lang Lin, Pavel Loiko, Feifei Yuan, Ge Zhang, Zhoubin Lin, Xavier Mateos, Valentin Petrov, Weidong Chen

{"title":"Spectroscopy and SESAM mode-locking of a disordered Yb:Gd2SrAl2O7 crystal.","authors":"Huang-Jun Zeng, Zhang-Lang Lin, Pavel Loiko, Feifei Yuan, Ge Zhang, Zhoubin Lin, Xavier Mateos, Valentin Petrov, Weidong Chen","doi":"10.1364/OE.559152","DOIUrl":"https://doi.org/10.1364/OE.559152","url":null,"abstract":"We report on the polarized spectroscopy, continuous-wave laser operation, and mode-locked laser performance of an ytterbium-doped disordered tetragonal rare-earth strontium aluminate crystal, Yb3+:Gd2SrAl2O7. In the continuous-wave regime, the diode-pumped Yb:Gd2SrAl2O7 laser generated a maximum output power of 487 mW at 1064 nm (π-polarization), with a slope efficiency of 61%. By employing a commercial SESAM to initiate and stabilize soliton-like pulse formation, the mode-locked Yb:Gd2SrAl2O7 laser generated transform-limited pulses as short as 38 fs at 1065.7 nm, with an average output power of 87 mW at a repetition rate of ∼66.5 MHz. The average output power was further scaled to 131 mW for slightly longer pulse duration of 43 fs, corresponding to a peak power of 40.3 kW and a laser efficiency of 15.5%. To the best of our knowledge, this is the first demonstration of mode-locked laser operation of the Yb:Gd2SrAl2O7 crystal.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 7","pages":"15057-15066"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144036300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Linearity improvement of chirped distributed feedback laser diodes based on an analog electro-optical phase-locked loop. 基于模拟电光锁相环的啁啾分布反馈激光二极管线性度改善。

IF 3.2 2区物理与天体物理

Optics express Pub Date : 2025-04-07 DOI: 10.1364/OE.551333

Xiang Li, Zhiqiang Fan, Jun Su, Yunxiang Wang, Shuangjin Shi, Qi Qiu

{"title":"Linearity improvement of chirped distributed feedback laser diodes based on an analog electro-optical phase-locked loop.","authors":"Xiang Li, Zhiqiang Fan, Jun Su, Yunxiang Wang, Shuangjin Shi, Qi Qiu","doi":"10.1364/OE.551333","DOIUrl":"https://doi.org/10.1364/OE.551333","url":null,"abstract":"A linearity improvement method for frequency-modulated distributed feedback laser diodes (DFB-LD) is proposed and demonstrated based on a pre-distortion signal and an electro-optical phase-locked loop (EO-PLL). The pre-distortion signal is used to reduce the deterministic frequency errors. The EO-PLL is further used to suppress the stochastic frequency noise and enhance the coherence of the DFB-LD. In the EO-PLL, the DFB-LD output is transmitted through a Mach-Zehnder interferometer (MZI) and detected by a photodetector (PD) to get a beat note signal, which denotes the nonlinearity of the chirp. A mixing signal, achieved by mixing the beat note signal with a fixed frequency reference signal, is then filtered by a proportional integral filter (PIF) and feedback to the DFB-LD to reduce the stochastic frequency noise in the chirp. The EO-PLL bandwidth can be adjusted by tuning the PIF response. Consequently, a linear chirp optical signal with an enhanced linearity is generated from the DFB-LD. In the experiment, 788- and 321-time linearity improvements are implemented when the loop bandwidths are about 100 and 550 kHz, respectively. Correspondingly, residual frequency errors of 1.65 and 4.85 MHz at 52- and 450-THz/s chirp rates are obtained.","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 7","pages":"15149-15158"},"PeriodicalIF":3.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144037557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0