We present double resonance optical pumping (DROP) spectra for the 5P3∕2–4D3∕2 transition and the 5P3∕2–4D5∕2 transition of R87b and we use these spectra for frequency stabilization in the 1.5μm region. The spectra, compared to the conventional double resonance spectrum, show a good signal-to-noise ratio and a narrow spectral linewidth for laser frequency stabilization. The different intensities of the hyperfine states were attributed to the different rates of double resonance optical pumping into the other ground state. When we stabilized the frequency of a 1.5μm laser diode to the DROP spectrum, the best frequency stability was 1×10−11 after 100s.
We demonstrate the spectra of 87Rb 5S1/2-5P3/2-4D3/2(4D5/2) transitions by utilizing the double-resonance optical-pumping(DROP) and optical-optical double-resonance(OODR) techniques,respectively.The DROP spectrum,compared with the traditional OODR spectrum,shows a much better signal-to-noise ratio(SNR) and narrower linewidth.When frequency of 1 529 nm external-cavity diode laser is stabilized to the DROP spectrum of 87Rb 5P3/2(F′=3)-4D3/2(F″=3) transition,the preliminary result of residual frequency jitter after being locked is～0.65 MHz within 300 s.This result is clearly much better than that in case of frequency stabilized by using OODR scheme(～1.8 MHz within 300 s).
We demonstrate the spectra of 87Rb 5S1/2 - 5P3/2 - 4D3/2 transitions by utilizing the double-resonance optical-pumping (DROP) and optical-optical double-resonance (OODR) techniques, respectively. The DROP spectrum, compared with the traditional OODR spectrum, show a much better signal-to-noise ratio (SNR). Paying special attention to the influence of alignment of lasers where the coupling and probe beams are counter-propagation and co-propagation on DROP spectrum, so as to further narrow the spectral width by means of electromagnetically induced transparency (EIT). When -the frequency of 1.5μm fiber-pigtailed butterfly-type distributed-feedback (DFB) diode laser is stabilized to the DROP spectrum of 87Rb 5P3/2 - 4D3/2 transition, the preliminary result of residual frequency jitter after stabilization is ~ ±1.3 MHz within 60 s.
우리는 이중공명 광펌핑(double resonance optical pumping; DROP)효과를 이용하여 루비듐(
87 Rb) 원자의 5P
3 2/-4D
3 2/와 5P
3 2/-4D
5 2/ 전이선에서 DROP 스펙트럼을 관측하고, 1.5
μm 레이저의 주파수를 무변조 안정화하였다. 관측한 DROP 스펙트럼은 기존의 광-광이중공명(optical-optical double resonance; OODR) 스펙트럼보다 높은 신호대잡음비를 가지며, 약 10 MHz의 좁은 선폭을 갖고 있다. DROP 스펙트럼의 상대적인 세기는 자발방출에 의한 광펌핑 정도로 설명할 수 있었다. DROP스펙트럼에 안정화된 1.5
μm 레이저의 주파수 흔들림은 샘플링 시간 0.1초에서 0.2 MHz로 측정되었고, 상대주파수 흔들림은 평균시간 100초에서 약 1
× 10−11 이었다. We present the double resonance optical pumping(DROP) spectra in the transition 5P
3 2/-4D
3 2/ and 5P
3 2/-4D
5 2/ of (
87 Rb) and the frequency stabilization in the
1.5mutextrmm region using those spectra. Those spectra have high signal-to-noise ratio and narrow spectral linewidth, which is about 10 MHz. We could account fur the relative intensities of the hyperfine states of those spectra by the spontaneous emission into the other state. When the frequency of the
1.5mutextrmm laser diode was stabilized to the DROP spectrum, the frequency fluctuation was about 0.2 MHz fDr sampling time of 0.1 s and the Allan deviation(or the square root of the Allan variance) was about 1
× 10
−11 for averaging time of l00s.
We have studied double-resonance optical pumping (DROP) as a function of the polarization combination of lasers, laser power, and the alignment of lasers in the 5S1/2-5P3/2-D3/2,5/2 ladder-type system of Rb87 atoms. By considering the two-photon transition probability and optical pumping effects, the changes in the relative magnitude of the DROP hyperfine structures as a function of the polarization combination of the lasers were analyzed theoretically. The theoretical results are in good agreement with the experimental results. Owing to the low optical pumping effect in the cycling transition, we could see the dependence of the spectrum on the laser power in the 5P3/2-4D5/2 transition distinctly. Also, the spectral linewidths as a function of the alignment between the lasers were measured 12.2 MHz for copropagating beams and 6.9 MHz for counterpropagating beams.
The spectra of cesium 6P3/2 - 8S1/2 excited-state transition have been obtained using double resonance optical-pumping (DROP) technique in a room-temperature vapor cell, and have shown a much better signal-to-noise ratio (SNR) compared with that using the traditional optical-optical double resonance (OODR) method. Furthermore, the line-width of DROP spectra is obviously narrowed by electromagnetically-induced transparency (EIT) effect in cesium 6S1/2 F=4 - 6P3/2 F'=5 - 8S1/2 F''=4 transitions. Finally, such DROP spectrum of 6P3/2 F'=5 - 8S1/2 F''=4 transition with a high SNR and a narrow line-width is applied into frequency stabilization of a 795 nm external-cavity diode laser, and the residual frequency fluctuation is ~ 600 kHz within 500 s.