我們建立了一套885 nm穩頻雷射系統，藉由電光調製器將一外腔式半導體雷射頻率鎖在銫原子6S1/2-6D3/2的交叉譜線躍遷上，穩定度在200秒平均時間為10-12 (受限於銫原子鐘的穩定度)。我們使用偏頻鎖頻技術控制另外一台外腔式半導體雷射，透過Doppler free雙光子躍遷光譜測量銫原子6S1/2-6D3/2的躍遷頻率。經過對light shift以及磁場的修正，推得超精細常數為A=16.3351(8) MHz B=-0.092(9) MHz C=0.0029(4) MHz。除此之外，考慮了殘餘氣體對銫原子能階可能的影響，我們在真空系統中量測銫原子6S1/2-6D3/2¬躍遷的絕對頻率，其值分別為6S1/2 F=4 - 6D3/2 F=5: 338 595 897 162 (51) kHz 以及6S1/2 F=3 - 6D3/2 F=5: 338 600 493 491 (15) kHz;We developed an 885-nm frequency stabilized laser system locked via Cesium 6S1/2-6D3/2 crossover-line transition with electro-optical modulator. The stability of laser frequency is 10-12 at 200-seconds average time. We offset locked a slave laser to probe the hyperfine structure of Cesium 6D3/2 via the Doppler free two-photon transition spectra. After extrapolating the light shift and the Zeeman shift, the Cesium 6D3/2 coupling constants A and B and C are determined as A=16.3351(8) MHz; B=-0.092(9) MHz; C=0.0029(4) MHz, which is the first time to our knowledge pushing the spectral resolution to C constant in this transition. Besides, to avoid any collision shift by alien gas, we performed the absolute frequency measurement of 6S1/26D3/2 transition with a cesium cell whose vacuum was always kept at 10-10 by an ion pump. We obtained the value of 338 595 897 162 (51) kHz for 6S1/2 F=4 - 6D3/2 F=5 and 338 600 493 491 (15) kHz for 6S1/2 F=3 - 6D3/2 F=5 respectively.
