铯原子852 nm共振型超窄带宽非线性光学滤波器  

Cesium Atom 852 nm Resonant Ultra-Narrow Bandwidth Nonlinear Optical Filter

作　　者：薛朝 杨保东[1,2] 臧珂茹 周海涛[1] Xue Zhao;Yang Baodong;Zang Keru;Zhou Haitao(College of Physics and Electronic Engineering,Shanxi University,Taiyuan 030006,Shanxi,China;State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,Shanxi,China)

机构地区：[1]山西大学物理电子工程学院,山西太原030006 [2]山西大学光电研究所量子光学与光量子器件国家重点实验室,山西太原030006

出　　处：《光学学报》2024年第16期269-277,共9页Acta Optica Sinica

基　　金：国家自然科学基金(61975102);山西省自然科学基金(20210302123437);山西省高等学校科技创新项目(2019L0101)。

摘　　要：基于铯原子6S_(1/2)→6P_(3/2)跃迁线,综合利用圆二向色性、饱和吸收效应和法拉第磁致旋光效应,实现了工作波长为852 nm的共振型超窄带宽非线性光学滤波器。在实验中详细测量并分析了泵浦光功率、铯原子气室温度、磁场大小、信号光功率对该光学滤波器性能的影响。在优化的实验参数下,铯原子6S_(1/2)(F=4)→6P_(3/2)(F′=4、F′=5)交叉跃迁线处滤光器的峰值透射率约为29.6%,半峰全宽约为36.5 MHz;6S_(1/2)(F=3)→6P_(3/2)(F′=2、F′=4)交叉跃迁线处滤光器的透射率约为7.4%,半峰全宽约为28.7 MHz。与传统的法拉第反常色散光学滤波器相比,该非线性光学滤波器的带宽至少窄2个数量级。超窄带宽的光学滤波器在激光频率锁定、自由空间光通信、窄带量子光的产生等方面具有潜在的应用价值。Objective Atomic optical filters are widely utilized in free-space optical communication,laser frequency stabilization,and other fields due to their narrow bandwidth,high transmission,and excellent noise suppression capabilities.Several methods are commonly employed to achieve these filters.The Faraday anomalous dispersion optical filter(FADOF)and Voigt anomalous dispersion optical filter(VADOF)use magnetic fields to induce birefringence in atomic vapor,resulting in the rotation of the polarization plane of the signal light.These methods have been extensively researched.While magneto-optical rotation filters have narrow bandwidths,they are typically on the order of GHz.Another type,the induced-dichroism atomic optical filter(IDAOF),utilizes circularly polarized laser light to polarize the atomic medium and induce polarization plane rotation without needing a magnetic field,achieving narrower bandwidths on the order of MHz.Thus,developing ultra-narrow bandwidth and high transmission atomic optical filters at various wavelengths and with different atoms is a significant research focus.Methods We realize an ultra-narrow bandwidth nonlinear optical filter at an operating wavelength of 852 nm based on the^(133)Cs atom 6S_(1/2)→6P_(3/2)hyperfine transitions.The filter is achieved by leveraging circular dichroism,the saturated absorption effect,and the Faraday effect.The experimental setup(Fig.2)divides the 852 nm laser provided by the extended cavity diode laser into two parts:one beam serves as high-power pump light and is circularly polarized by adjusting the optical axis direction of aλ/4 wave plate,while the other beam,with lower power,acts as the signal light and passes through a^(133)Cs atomic vapor cell(5 cm length,no buffer gas).A pair of Glan-Taylor prisms with an extinction ratio up to 105∶1 and perpendicular polarization directions is placed on both sides of the^(133)Cs vapor cell.The temperature of the^(133)Cs vapor cell can be adjusted from room temperature to 150℃with an accuracy of less than 1℃.

关 键 词：非线性光学 滤光器 超窄带宽 法拉第磁致旋光效应 圆二向色性 

分 类 号：O562[理学—原子与分子物理]