【摘要】 介绍了633 nm半导体激光频标系统,高重复频率锁相飞秒激光器系统和绝对频率测量系统的建立以及测量碘分子超精细跃迁绝对频率的系统方案。633 nm半导体激光频标采用三次微分稳频方法,将激光频率锁定在碘分子谱线上,获得0.5 mW的稳频激光输出。飞秒激光稳频系统通过锁相电路将飞秒激光的高重复频率(760 MHz)和初始频率稳定在微波频率标准上,从而得到稳定的飞秒光梳,其稳定度优于6.44×10-13。在此基础上建立了绝对频率的直接测量系统,即利用波长计直接测量光梳的齿数n,并通过拍频法,测出633 nm半导体激光频标与飞秒光梳的差频,从而计算出相应谱线的绝对频率。这样,通过锁相飞秒激光器,建立了微波频率标准到光学频率标准的传递,为进一步的基础研究工作奠定了基础。更多还原

【Abstract】 We developed a system to measure the absolute frequency of transition of I2 based on phased locked femto-second laser. The system mainly includes phased locked femto-second laser with repetition frequency of 760 MHz and the 633 nm frequency standard of ECL based on third-harmonic frequency stabilization of iodine saturation absorption. The stabilization of frequency of the femto-second comb generator was achieved by locking both of the repetition frequency (fr) and the carrier envelope offset frequency (fceo) with homemade phase locked circuits and commercial microwave frequency standard. The stability was estimated up to 6.44×10-13. The absolute frequency was measured by beat frequency between the 633 nm frequency standard locked on the iodine hyperfine transitions and femto-second frequency comb with the help of wavelength meter. Therefore, the transfer from the microwave frequency standard to the optic frequency standard based on the phase locked femto-second laser system has been established, which makes the foundation for the further research.更多还原