Abstract:
A laboratory prototype of a compact quantum frequency standard based on a rubidium vapour cell with pulsed laser pumping is developed. With significantly smaller overall dimensions (a volume of ~10 L and a mass of ~10 kg), the frequency standard is expected to have the short-term instability comparable with that of the commercial passive hydrogen masers and even the laboratory fountaintype atomic clocks based on cold atoms. The advantages of the technique of pulsed optical pumping and pulsed excitation of microwave resonances over the traditional techniques of double radio-optical resonance detection are substantiated. The results of the experimental study of pulsed optical pumping of a rubidium cell with a mixture of buffer Ar – Ne gases implemented at the VNIIFTRI are presented, the Ramsey resonances are obtained, and the process of optimising the contrast of the central resonance peak is described.
Keywords:quantum frequency standard with a rubidium vapour cell, pulsed optical pumping, Ramsey scheme of microwave excitation, diode laser, saturated absorption spectroscopy, modulation transfer spectroscopy, acousto-optic modulator, Raman–Nath diffraction.