Measurement of the characteristics of the optical-microwave double-resonance effect of the 87Rb D1 line for application as an atomic frequency

This paper reports the OMDR (optical-microwave double resonance) spectrum of 87Rb studied for enabling use of a frequency stabilized GaAs semiconductor laser as a pumping source in a gas cell-type Rb frequency standard. 87Rb of a natural isotopic abundance was sealed in a glass cell with buffer gases (Ar/N2 = 1.2, total pressure = 39 torr). The double resonance signal in the 5P1/2(F = 2) left-arrow 5s1/2(F = 1) transition appearing at the resonance to the F = 2 left-arrow 1 hyperfine transition of the 5S1/2 state was detected. The optimum operational cell temperature was 56 degrees C. The peak-to-peak frequency width of the atomic hyperfine resonance discriminator used to stabilize the microwave frequency was 380 Hz. The microwave frequency shifts induced by detuning of the laser frequency, changes in the laser and microwave powers, and temperature drift of the cell were investigated