A 532 nm molecular iodine optical frequency standard based on modulation transfer spectroscopy

• 作者: Feihu Cheng Ning Jin Fenglei Zhang Hui Li Yuanbo Du Jie Zhang Ke Deng Zehuang Lu
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（5）
• 所属期刊栏目: GENERAL
• 页码范围: 311-321
• 页数: 11页
• 语种: 英文
• DOI: 10.1088/1674-1056/abd754

摘要

We report construction of an iodine-stabilized laser frequency standard at 532 nm based on modulation transfer spec-troscopy (MTS) technology with good reproducibility.A frequency stability of 2.5 × 10-14 at 1 s averaging time is achieved,and the frequency reproducibility has a relative uncertainty of 3.5 × 10-13,demonstrating the great stability of our setup.The systematic uncertainty of the iodine-stabilized laser frequency standard is evaluated,especially the contribution of the residual amplitude modulation (RAM).The contribution of the RAM in MTS cannot be evaluated directly.To solve this problem,we theoretically deduce the MTS signal with RAM under large modulation depth,and prove that the non-symmetric shape of the MTS signal is directly related to the MTS effect.The non-symmetric shape factor r can be calibrated with a frequency comb,and in real experiments,this r value can be obtained by least-squares fitting of the MTS signal,from which we can infer the RAMinduced frequency shift.The full frequency uncertainty is evaluated to be 5.3 kHz (cor-responding to a relative frequency uncertainty of 9.4× 10-12).The corrected transition frequency has a difference from the BIPM-recommended value of 2 kHz,which is within 1σ uncertainty,proving the validity of our evaluation.