Nonlinear Frequency Translation in Micromachined Rb Vapor Cells

Heleni Krelman; Ori Nefesh; Liron Stern

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arXiv · 2605.01997

Nonlinear Frequency Translation in Micromachined Rb Vapor Cells

Heleni Krelman·Ori Nefesh·Liron Stern

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Abstract

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.

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Heleni Krelman, Ori Nefesh, Liron Stern. 2026-05-03. Nonlinear Frequency Translation in Micromachined Rb Vapor Cells. https://arxiv.org/abs/2605.01997

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