The ALOHA research program aims to propose a breakthrough generation of instrument for high resolution imaging in astronomy. This fully innovative concept results from our unique skills with simultaneous competences in nonlinear optics and high resolution imaging with telescope arrays. Acting like a mixer in a radio receiver, the nonlinear process (sum frequency generation) shifts the infrared radiations emitted by the observed astrophysical source to the visible spectral domain. This way, the light beam is more easily processed by mature optical devices and detectors. The compatibility of the nonlinear process with the spatial coherence analysis has been successfully tested through preliminary in lab experiments. Now it’s time to apply this technique in a real astronomical environment for MIR observations at CHARA. First on-sky fringes have been observed for the first time during the spring mission in 2015 with a limiting magnitude equal to 3 in the H band. The current project is focusing on the L band version of ALOHA CHARA at 3.4 µm.


Instrument Papers

Proposal for the Implementation of the ALOHA Up-Conversion Interferometer on the CHARA Telescope Array, J.T. GOMES, L. DELAGE , R. BAUDOIN , L. GROSSARD, F. REYNAUD, T. A. TEN BUMMELAAR, N. J. SCOTT , J. STURMANN and V. COUDÉ DU FORESTO, Journal of Astronomical Instrumentation (IF : NA nouvelle revue), Vol. 3, Nos. 3 & 4, pp. 1450008, DOI : 10.1142/S2251171714500081 (2014)


ALOHA 1.55 μm Implementation on the CHARA Telescope Array : On-sky sensitivity tests, R. BAUDOIN , P. DARRÉ , J-T. GOMES , M.FABERT, L. GROSSARD , L. DELAGE , F. REYNAUD, N. J. SCOTT , J. STURMANN , T. A. TEN BRUMMELAAR and V. COUDÉ DU FORESTO Journal of Astronomical Instrumentation (IF : NA nouvelle revue), p. 1650006, May 2016


On-sky fringes with an up-conversion interferometer tested on a telescope array, P. DARRÉ, R. BAUDOIN, J. -T. GOMES, N. J. SCOTT, L. DELAGE, L. GROSSARD, J. STURMANN, C. FARRINGTON, F. REYNAUD and T. A. BRUMMELAAR , Phys. Rev. Lett. (IF : 8.46) 117, 233902, American Physical Society, 2016


In-laboratory ALOHA mid-infrared up-conversion interferometer in the photon counting regime at λ = 3.39 μm L. SZEMENDERA L. GROSSARD, L. DELAGE and F. REYNAUD, Monthly Notices of the Royal Astronomical Society, (IF 4,96), 468, 3484–3488 (2017) doi:10.1093/mnras/stx780



Schematic of the ALOHA combiner.