A laser transition based on fluctuations

K. Beloy

We examine the influence of probe-laser-intensity fluctuations on hyper-Ramsey spectroscopy. We assume, as is appropriate for relevant cases of interest, that the probe-laser intensity $I$ determines both the Rabi frequency ($\ensuremath{\propto}\sqrt{I}$) and the frequency shift to the atomic transition ($\ensuremath{\propto}I$) during probe-laser interactions with the atom. The spectroscopic signal depends on these two quantities that covary with fluctuations in the probe-laser intensity. Introducing a simple model for the fluctuations, we find that the signature robustness of the hyper-Ramsey method can be compromised. Taking the ${\mathrm{Yb}}^{+}$ electric octupole clock transition as an example, we quantify the clock error under different levels of probe-laser-intensity fluctuations.

J. T. Malos

C. R. Willis

We derive and analyze the master equation for absorptive and dispersive optical bistability in the high-Q cavity limit where the driving laser has both amplitude and phase fluctuations which are larger than the small amplitude and phase fluctuations caused by incoherent spontaneous emission in the cavity. We treat the amplitude and phase fluctuations of the driving laser as independent time dependent Gaussian processes. The causes of jitter and amplitude fluctuations will vary from laser to laser and the fluctuations need not be Gaussian. However, we use Gaussian processes for mathematical tractability and because we expect them to be qualitatively correct. Recently,1 we have shown in the case of absorptive optical bistability when the driving laser has phase fluctuations the fundamental process which determines the statistical properties of the internal field is the competition between locking of the internal field phase to the phase of the driving laser and the diffusion of the phase of the internal field as a consequence of the driving laser fluctuations. The driving laser fluctuations have little effect if the phase locking rate is larger than the phase diffusion rate caused by the driving laser’s fluctuations. However, when the diffusion rate becomes comparable to the locking rate we find the amplitude of the 2 internal field is reduced and the dimensionless parameter2 measuring the importance of transitions from one branch of the OB curve to the other due to fluctuations takes on a value which leads to an appreciable transition rate due to fluctuations.

W. H. Louisell, M. Lax

Wolfgang Jitschin

Paul Avan, Claude N. Cohen-Tannoudji

The theoretical method developed in a previous paper (see ibid., vol.10, no.2, p.155 (1977)) is applied to the study of the sensitivity of Hanle resonances to the fluctuations of an intense quasi-monochromatic laser beam. The calculations are performed for the simplest possible transition J=0 to or from J=1. Quantitative expressions are derived for the level-crossing signals which appear to be quite perturbed by the fast phase fluctuations.