相位噪声抑制的捷变频电光频率梳

Frequency-Agile Electro-Optic Comb with Suppressed Phase Noise

报道了一种单调制器电光频率梳产生技术,其重复频率高速可调,调频速率达1 MHz。经非线性光纤展宽,光梳谱宽可达1.25 THz(约10 nm,中心波长1550 nm),含4800根间隔为260 MHz的窄线宽梳齿。单模光纤色散补偿后,脉宽为260 fs。研究了光纤放大与非线性光谱展宽对梳齿相干性的影响,并采用声光调制器对梳齿的共模相位噪声进行了前馈式抑制。该光源在分子光谱及干涉测距等领域具有应用前景。

In this paper,we report on a singlemodulator electrooptic frequency comb whose repetition frequency can be modulated at high speed with a modulation rate of 1 MHz.With spectral broadening in a nonlinear fiber,a comb spectrum spanning 1.25 THz(10 nm,the central wavelength is 1550 nm)with 4800 narrowlinewidth combs separated by 260 MHz is achieved.The optical comb pulse width is compressed to 260 fs by dispersion compensation in a singlemode fiber.Also,the impacts of optical fiber amplification and nonlinear spectral broadening on the comb coherence are studied,and the commonmode phase noise of the comb is suppressed by a feedforward method based on the acoustooptic modulator.The developed electrooptic comb has promising applications for molecular spectroscopy and interferometric ranging.