Low-coherence interferometry with undetected mid-infrared photons in the high-gain regime

Abstract

We develop a high-parametric-gain SU(1,1) interferometer based on an aperiodically poled Potassium Titanyl Phosphate (apKTP) crystal, enabling frequency-domain low-coherence interferometry with undetected mid-infrared photons. The system achieves a signal-to-noise ratio as high as 40 dB and axial resolution of 30 $\mu$m, with a 3 $\mu$m-centered idler beam. By increasing the poling-period range, we also improve the axial resolution to 17 $\mu$m, demonstrating a straightforward route to enhance the performance by working on the crystal design

14 pages, 11 figures

References in corpus (2)

• Sub-shot-noise photon-number correlation in mesoscopic twin-beam of light
• Generation of monocycle squeezed light in chirped quasi-phase-matched nonlinear crystals