A frequency standard via spectrum analysis and direct digital synthesis

Abstract

We demonstrated a frequency standard based on a detuned coherent population beating phenomenon. In this phenomenon, the beat frequency of the radio frequency for laser modulation and the hyperfine splitting can be obtained by digital signal processing technology. After analyzing the spectrum of the beat frequency, the fluctuation information is obtained and applied to compensate for the frequency shift to generate the standard frequency by the digital synthesis method. Frequency instability of 2.6 × 1012 at 1000 s is observed in our preliminary experiment. By eliminating the phase-locking loop, the method will enable us to achieve a full-digital frequency standard with remarkable stability.

Transient dynamics of a nonlinear magneto-optical rotation

“…The transient dynamics of optical signals can also be used practically. For example, atomic clock based on transient oscillations of CPT signal were demonstrated [15][16][17]. Recently, the time domain analysis of the coherent transient oscillations has been used for magnetometry [18][19][20][21][22].…”

A magnetometer based on coherent population beating

“…As is shown in Fig.2, for m F =0 ground state hyperfine energy levels, they are insensitive to external magnetic field, which can be used to achieve a CPB atomic clock [5]. Here we move the CPB effect to the ground levels of m F =1 or m F =-1, which are sensitive to external magnetic field.…”

Dynamic Continuous-Wave Spectroscopy of Coherent Population Trapping at Phase-Jump Modulation

“…Note that our approach is radically different from the dynamic frequency-step method [17,18]. Indeed, if we present phase-jump modulation in its frequency equivalent (ν = dϕ/dt), we will have a time representation of alternating δ-functions with different signs at the times of phase jumps.…”

“…In particular, there is growing interest not only in standard stabilization schemes in which relatively slow harmonic mod-ulation is used to form the error signal, but also in stabilization modes using the dynamic response of the quantum system. For example, a frequency standard based on the transition process in a spectroscopic signal with frequency-step modulation was proposed and implemented in [17,18].…”