Video‐Rate Imaging with Undetected Photons

Abstract

Imaging and microscopy are some of the most important tools in modern life science for getting new insights into metabolisms or unravelling bio‐chemical processes. However, in particular low‐light observations outside the visible spectrum are still challenging and a limiting factor. A rugged, label‐free quantum imaging system is presented capable of recording at video rate in the visible regime, while illuminating the sample with undetected light of different wavelength. The results pave the way for a field deployable quantum imaging device allowing live‐cell imaging in extreme spectral ranges with a minimal photo dose.

Quantum holography with undetected light

“…For this case, the maximum phase noise was measured to be (0.091 ± 0.005)π, which is the lowest detectable phase difference. The transmission of the object was measured to be homogeneous with t = (94 ± 1)% as in agreement with the theory taking into account the visibility with and without object ( 24 ).…”

“…In an alternative configuration, usually termed as SU(1,1) interferometer, the signal photons generated in the first nonlinear crystal are also injected in the second nonlinear crystal as the idler photons ( 19 , 21 , 24 , 26 , 31 ). Quantum interference explains the physical origin of the interference pattern for both configurations, and the mathematical expressions that describe the shape of this interference pattern are mostly equal.…”

“…5 (A and B) for OD 0 and OD 0.4, respectively. The modulation of the interference and the transmission of the object follow a proportional relationship ( 24 ). The colored rectangles in Fig.…”

“…Our approach has reduced the required level phase stability to the order of 2 s (the time scale over which a complete round of phase settings can be applied). These levels of stability are straightforward to achieve in ruggedized optical assemblies ( 24 )—a key advancement toward practical deployment.…”

“…In particular, single-photon holography with undetected light in a nonlinear interferometer scheme ( 19 – 22 ) would introduce the benefit of choosing the most convenient spectral range for the probing beam in an application without facing the limitations imposed by the low efficiency of detectors at those specific spectral range (e.g., in the mid-infrared). Nonlinear interferometry has been proven to be key elements in numerous applications, namely, in imaging ( 6 , 23 , 24 ), sensing ( 25 ), spectroscopy ( 7 , 26 ), microscopy ( 27 , 28 ), and optical coherence tomography ( 26 , 29 – 31 ).…”