Coherence and Quantum Optics V

Qian Li, Yifan Sun, Ling‐Jun Kong +1 more

Quantum optical coherence tomography (QOCT) is the non-classical counterpart of optical coherence tomography (OCT), by which quantum interference of entangled photon pairs is used to show some advantages over classical OCT. Currently, almost all research on the QOCT focuses on the case with two photons and a twofold improvement in axial resolution has been demonstrated. Here, we introduce the multiple reflections strategy into the QOCT scheme, referencing the multi-pass strategy of the sequential scheme in quantum metrology, and provide a theoretical framework for multi-reflection quantum-optical coherence tomography (MQOCT). According to such a scheme, when the incident light interacts with the sample N times, the axial resolution of MQOCT is theoretically enhanced by a factor of N compared to that of QOCT under the same spectral bandwidth while preserving the dispersion cancellation capability of QOCT. Furthermore, we present a classical optical analogy of MQOCT using P -beam correlated multi-mode broadband beams and experimentally validate it. The classical optical analogy of MQOCT theoretically has the same resolution enhancement capability and dispersion cancellation capability as MQOCT while avoiding the fragility issues associated with the quantum light source which is used in MQOCT.

R. Loudon

Joseph H. Eberly, L. Mandeļ, E. Wolf

Kyohei Hayama, Bo Cao, Ryo Okamoto +3 more

Quantum optical coherence tomography (QOCT) is a promising approach to overcome the degradation of the resolution in optical coherence tomography (OCT) due to dispersion. Here, we report on an experimental demonstration of QOCT imaging in the high-resolution regime. We achieved a depth resolution of 2.5 μ m, which is the highest value for QOCT imaging, to the best of our knowledge. We show that the QOCT image of a dispersive material remains clear whereas the OCT image is drastically degraded.

Ayman F. Abouraddy, Magued B. Nasr, Bahaa E. A. Saleh +2 more

We propose a technique, called quantum-optical coherence tomography (QOCT), for carrying out tomographic measurements with dispersion-cancelled resolution. The technique can also be used to extract the frequency-dependent refractive index of the medium. QOCT makes use of a two-photon interferometer in which a swept delay permits a coincidence interferogram to be traced. The technique bears a resemblance to classical optical coherence tomography (OCT). However, it makes use of a nonclassical entangled twin-photon light source that permits measurements to be made at depths greater than those accessible via OCT, which suffers from the deleterious effects of sample dispersion. Aside from the dispersion cancellation, QOCT offers higher sensitivity than OCT as well as an enhancement of resolution by a factor of two for the same source bandwidth. QOCT and OCT are compared using an idealized sample.

Michael Berry