We present an upconversion imaging experiment from the near-infrared to the visible spectrum. Using a dedicated broadband pump laser to increase the number of resolved elements converted in the image we obtain up to 56x64 spatial elements with a 2.7 nm wide pump spectrum, more than 10 times the number of elements accessible with a narrowband laser. Results in terms of field of view, resolution and conversion efficiency are in good agreement with simulations. The computed sensitivity of our experiment favorably compares with direct InGaAs camera detection.

We report the experimental study of an atom-chip interferometer using ultracold rubidium 87 atoms above the Bose-Einstein condensation threshold. The observed dependence of the contrast decay time with temperature and with the degree of symmetry of the traps during the interferometer sequence is in good agreement with theoretical predictions published in Dupont-Nivet et al (2016 New J. Phys. 18 113012). These results pave the way for precision measurements with trapped thermal atoms.

We report an upconversion experiment using an orientation-patterned gallium arsenide (OP-GaAs) crystal to detect small mid-infrared signals on an InGaAs avalanche photodiode. A conversion efficiency up to 20% with a nonpolarized pulsed fiber pump is demonstrated. Our uncooled setup is favorably compared in terms of noise equivalent power, dynamic range, and response time to cryogenically cooled HgCdTe detectors. Its dependence on the polarization of both the pump and signal beams is also investigated.

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