We present an inverse weak value amplification (IWVA) scheme to perform precision frequency measurements in an integrated optics environment. The IWVA technique allows us to amplify small signals by introducing a weak perturbation to the system and performing a post-selection on the data. A Bragg grating with two band gaps is used to convert the optical frequency into a phase, and a perturbation is applied to the mode coefficients. We demonstrate the advantages of a Bragg grating with two band gaps for obtaining high transmission and low group velocity. We numerically model the interferometer, and demonstrate that we obtain the desired amplification effect. By using an on-chip device instead of a free space implementation, precision measurements can be carried out in a small volume with reliable performance.
This paper will overview recent progress in time-dependent metrology. By applying coherent control to a quantum system, we will demonstrate that the amount of information about a parameter can be increased by typically a power law in the duration time of the experiment. Several examples will be given: measurement of an external oscillation frequency, the Landau-Zehner transition, and the details of a recent experiment realizing these physical predictions. A simple example will be analyzed in detail to illustrate the ingredients of the theory.
We consider the non-equilibrium noise properties of bistable systems. The stochastic path integral formalism is derived and used to investigate the dynamics and distribution of transmitted charge. Microscopic fluctuations induce transitions between the two stable states, with rates found from an instanton calculation. On a long time scale, the system exhibits a random telegraph signal between the currents produced by the two stable states. We predict a universal ellipse law for the log-distribution of transmitted charge in the bistable current range, which applies to any type of bistable system, regardless of its origin.