论文标题
来自可伸缩的几个周期纤维激光器的六链频率梳子
A six-octave optical frequency comb from a scalable few-cycle erbium fiber laser
论文作者
论文摘要
对于多种应用，可提供从紫外线到红外的光谱覆盖的紧凑型连贯的激光光源，包括异差超级分辨率成像[1]，宽带红外显微镜[2]，蛋白质结构的确定[3]和僵化的大气 - 大气 - 大气 - 痕量GAS检测[4]。在解决这些苛刻的测量问题时，激光频率梳[5]将用户定义的光谱分辨率与次秒定时和波形控制结合在一起，以实现高分辨率，高速和宽带光谱的新方式[6-9]。在这封信中，我们引入了可扩展的近节循环的来源，由健壮和低噪声纤维（ER：纤维）技术产生的0.56 MW脉冲，我们使用它来产生一个频率梳子，该频率始于紫外线（350 nm）到中期（22500 nm）。高峰值功率使我们能够利用红外透明的非线性晶体（Linbo $ _3 $，GASE和CSP）中的二阶非线性，以提供相位稳定的红外超短脉冲的强大来源，该脉冲具有同时的光谱亮度，超过了基础亮度，超过了基础亮度[10]。 Linbo $ _3 $中的额外级联二阶非线性带有四个同时覆盖范围（0.350至5.6 $μ$ m）。在193 THz的梳子齿线宽为10 kHz的情况下，我们意识到跨带宽0.86 phz的光谱分辨能力超过10 $^{10} $。我们预计，这种紧凑且可访问的技术将为多带精度光谱，相干显微镜，超高灵敏度纳米镜检查，天文学光谱和精密载流子 - 固定阶段（CEP）稳定强场现象打开新的机会。
A compact and robust coherent laser light source that provides spectral coverage from the ultraviolet to infrared is desirable for numerous applications, including heterodyne super resolution imaging[1], broadband infrared microscopy[2], protein structure determination[3], and standoff atmospheric trace-gas detection[4]. Addressing these demanding measurement problems, laser frequency combs[5] combine user-defined spectral resolution with sub-femtosecond timing and waveform control to enable new modalities of high-resolution, high-speed, and broadband spectroscopy[6-9]. In this Letter we introduce a scalable source of near-single-cycle, 0.56 MW pulses generated from robust and low-noise erbium fiber (Er:fiber) technology, and we use it to generate a frequency comb that spans six octaves from the ultraviolet (350 nm) to mid-infrared (22500 nm). The high peak power allows us to exploit the second-order nonlinearities in infrared-transparent, nonlinear crystals (LiNbO$_3$, GaSe, and CSP) to provide a robust source of phase-stable infrared ultra-short pulses with simultaneous spectral brightness exceeding that of an infrared synchrotron[10]. Additional cascaded second-order nonlinearities in LiNbO$_3$ lead to comb generation with four octaves of simultaneous coverage (0.350 to 5.6 $μ$m). With a comb-tooth linewidth of 10 kHz at 193 THz, we realize a notable spectral resolving power exceeding 10$^{10}$ across 0.86 PHz of bandwidth. We anticipate that this compact and accessible technology will open new opportunities for multi-band precision spectroscopy, coherent microscopy, ultra-high sensitivity nanoscopy, astronomical spectroscopy, and precision carrier-envelope phase (CEP) stable strong field phenomena.
