Leonid Krivitsky
Data Storage Institute
Leonid obtained his PhD from Moscow State University in 2005 with specialization in experimental quantum optics. Then he worked as a postdoc in Turin, Erlangen and Copenhagen. In 2008 he moved to ASTAR in Singapore, where he started his research group. He realized the first interface between the single photon source and live retinal photoreceptor, which lead to demonstration of single photon sensitivity of photoreceptors. He also realized the nonlinear spectroscopy method which allows characterization of samples in the Infrared range using visible light optics.
1. Introduction.
Light in the infrared (IR) optical range is widely used for characterization and imaging in multiple industries. Although conventional methods of IR measurements such as Fourier Transform IR spectroscopy (FTIR) and Optical coherence tomography (OCT) are well developed, there are remaining challenges associated with high cost and low efficiency of IR light sources and detectors. Here we show that by exploiting effects of quantum optics it is possible to overcome this challenge and retrieve properties of the materials in the IR range from measurements of visible range photons.
2. Methodology
Our approach is based on the interference of correlated photons produced via spontaneous parametric down conversion. One of the photons is generated in the detection-friendly visible range, and its correlated counterpart in the IR range is used as a probe [1]. The interference fringes observed for the visible photon depend on the properties of the IR photon, probing the sample. Actual detection of IR photons is not required. We built a nonlinear analog of a Michelson interferometer and realize the absorption spectroscopy [2, 3], and the 3-D imaging OCT [4] in the IR range with actual measurements performed in the visible range.
3. Results
Our spectroscopy method shows good precision in determining the refractive index and absorption coefficient of the media in a broad range of IR wavelength. The OCT setup operates in a widely tunable IR range (1,5-3,5 micron), all with the same measurement configuration. The level of accuracy and axial resolution is shown to be comparable to state of the art systems.
4. Conclusions
Our work contributes to the development of versatile 3D imaging and material characterization systems working in a broad range of IR wavelengths, which do not require the use of IR-range equipment. Practical applications of our techniques include material analysis, sensing, imaging, and defectoscopy.
- D. Kalashnikov et al Nature Photonics 10, 98 (2016).
- A. Paterova et al Scientific reports 7, 42608 (2017).
- A. Paterova et al arXiv:1706.04739 (2017).
- A. Paterova et al 2018 Quantum Sci. Technol. https://doi.org/10.1088/2058-9565/aab567
