Advanced and non-conventional optical schemes

Romil Audhkhasi, Michelle L. Povinelli

The ability of metamaterials to manipulate optical waves in the spatial and spectral domain has provided opportunities for image encoding. This combined with recent advances in hyperspectral imaging suggest exciting new opportunities for secure encryption. In this work, we propose a multi-channel scheme for secure image transmission across multiple wavelength channels. In contrast to conventional encryption schemes that perform a 1-to-1 transformation on a given plain image, we propose a 1-to-n transformation. We show that our scheme provides security against attacks of varying complexity provided a reasonable number of spectral channels is used.

David S. Simon

Limin Liu, Jiajun Ren, Wei‐Hai Fang

Accurately simulating non-Markovian quantum dynamics in system-bath coupled problems remains challenging. In this work, we present a novel memory truncation scheme for the iterative quasi-adiabatic propagator path integral (iQuAPI) method to improve accuracy. Conventional memory truncation in iQuAPI discards all influence functional beyond a certain time interval, which is not effective for problems with a long memory time. Our proposed scheme selectively retains the most significant parts of the influence functional using the density matrix renormalization group algorithm. We validate the effectiveness of our scheme through simulations of the spin-boson model across various parameter sets, demonstrating faster convergence and improved accuracy compared to the conventional scheme. Our findings suggest that the new memory truncation scheme significantly advances the capabilities of iQuAPI for problems with a long memory time.

A. E. Kaplan

S. Bize, Bess Fang, Yann Le Coq +5 more

Abstract We present several developments aimed at improving the stability of optical lattice clocks. First, we present our developments of an optical lattice clock using neutral mercury. We mention recent advances made with the fermionic isotope 199Hg. We also mention our work aimed at using bosonic isotopes, which offer the possibility to circumvent the relatively short lifetime of the upper clock state in 199Hg. Second, we present our work on a non-destructive detection in a Sr optical lattice clock. We describe developments that brought the detection scheme from the classical non-destructive regime to the quantum non-destructive regime. Our detection scheme is practical and has the capability to the used beyond proving the principle. Finally, we present our work on laser stabilization using spectral hole burning in a Eu3+:Y2SiO5 crystal at cryogenic temperatures. We describe our development of low noise interrogation based on digital IQ modulation and detection that can probe multiple spectral features simultaneously, as well as several investigations towards fluctuating environmental factors. These advances, individually or combined for example with spectral purity transfer with combs and composite clock approaches, shall bring significant progress in clock stability and accuracy.

John N. Dodd