arXiv subjects

Heleni Krelman

Publications and source records attributed to Heleni Krelman.

3 recordsLinked to original sources

arXiv2026

Nonlinear Frequency Translation in Micromachined Rb Vapor Cells

The exceptional nonlinearity of alkali-metal vapors enables highly efficient nonlinear optical processes even at relatively low optical intensities. However, such processes have traditionally relied on centimeter-scale vapor cells. Here, we utilize a versatile chip-scale Rb vapor platform to generate coherent blue and mid-IR light in continuous-wave mode by means of resonant four-wave mixing. Optimized optical overlap with the atomic medium enables blue light generation of $\sim$20 $\mu$W over a very short interaction length, while maintaining a directly measured linewidth of $\sim$1 MHz, which is presently limited by the measurement apparatus. Comparison with a conventional glassblown vapor cell further shows that the micromachined platform can achieve higher coherent blue-light generation efficiency despite its substantially shorter interaction length. Moreover, an anodically bonded Si window enables to detect coherent mid-IR emission with collected powers of $\sim$50 nW. We further characterize the temperature dependence and input-power scaling of the blue emission, confirming efficient nonlinear conversion within these compact vapor cells. This chip-scale platform provides a versatile foundation for a range of nonlinear optical functions, from precise wavelength references and quantum light sources to next-generation quantum sensors.

physics.optics↗

arXiv2025

Chip-Scale Atomic Birefringent Diffractive-Optical-Elements

The interaction between light and vapors in the presence of magnetic fields is fundamental to many quantum technologies and applications. Recently, the ability to geometrically confine atoms into periodic structures has enabled the creation of chip-scale, micromachined hybrid atomic-diffractive optical elements. However, applying magnetic fields to such structures remains largely unexplored, offering potential for both fundamental and applied insights. Here, we present measurements of an atomic-diffractive optical element subject to magnetic fields. In contrast to the well-known polarization rotation in a Faraday medium, these diffractive atomic elements exhibit additional, rapidly oscillating rotation terms, which we validate both theoretically and experimentally. Moreover, we find that the introduction of spatially varying magnetic fields leads to a reduction in fringe visibility, which can be leveraged for gradiometric applications. Together, these effects establish a chip-scale platform where diffraction and quantum sensing are inseparably co-engineered, unveiling previously inaccessible regimes of atom-photon-magnetic interaction. By probing the magneto-optic response of periodically confined vapors, our results lay the groundwork for integrated smart-cell magnetometers and open new avenues for flat-optics-enabled quantum photonic devices.

physics.app-ph↗

arXiv2024

Laser Offset Stabilization with Chip-Scale Atomic Diffractive Elements

Achieving precise and adjustable control over laser frequency is an essential requirement in numerous applications such as precision spectroscopy, quantum control, and sensing. In many such applications it is desired to stabilize a laser with a variable detuning from an atomic line. In this study, we employ an offset-stabilization scheme by utilizing phase contrast spectroscopy in microfabricated atomic diffractive elements vapor-cells. The spectroscopic response of such a device generates oscillating optical fringes, providing multiple optical frequency stabilization points across a bandwidth of tens of gigahertz, centered around the absorption resonances of Rb. Using this device, we demonstrate laser stabilization at various offset frequencies with instabilities reaching sub-megahertz levels. We further explore the fundamental limitations of our hybrid atomic-photonic device, drawing parallels to birefringent and dichroic spectroscopy apparatuses, which are commonly employed for offset stabilization. Our system showcases a broad offset lock bandwidth, a highly compact footprint, scalability to chip-scale production, and the ability to operate without reliance on magnetic fields. These attributes pave the way for a multitude of applications in quantum technologies.

physics.app-ph↗