Presentation Information
[10p-E219-1][JSAP-Optica Joint Symposia Invited Talk] Hong-Ou-Mandel interferometry-based quantum sensing
〇Goutam Kumar Samanta1 (1.Physical Research Laboratory, India)
Keywords:
Quantum Optics,Quantum sensing,Nonlinear optics
Quantum sensing and imaging are emerging as key quantum technologies that exploit nonclassical states of light, quantum correlations, and entanglement to enable measurements beyond the capabilities of classical optical techniques. Among these resources, Hong–Ou–Mandel (HOM) interference, arising from the bunching of two indistinguishable photons at a balanced beam splitter, has become a powerful tool for precision metrology, imaging, and sensing. The resolution of HOM-based sensors is governed by the width of the HOM dip, which is determined by the spectral bandwidth of the pair photons. Conventionally, broadband photon pairs are generated using bulky and expensive ultrafast laser systems, limiting the practical deployment of HOM-based sensing technologies. We demonstrate the generation of high-brightness pair photons with flexible bandwidth using a compact cw diode laser, enabling high-precision, real-time sensing. Using a 1-mm-long PPKTP crystal, we generate broadband degenerate photon pairs that produce a narrow HOM dip, enabling displacement measurements as small as 60 nm and vibration amplitudes of 205 nm at 8 Hz. We further employ the HOM interferometer to measure temperature-dependent refractive-index changes of a sample, demonstrating its potential for precision-augmented in-field quantum sensing. We also developed a projection-free method for mapping 2D polarization distributions. Using pair photons at 810+/-2 nm, we reconstruct spatial polarization distributions with a fidelity of 95% and angular resolution of about 0.4o. Controlling the transition between symmetric and antisymmetric Bell states through birefringence-induced phase shifts and optical delays, we realize a quantum sensing modality capable of measuring thermo-optic birefringence changes on the order of 10-6/oC and optical delays as small as 10 nm. In this talk, I will present the fundamentals and our recent advances in HOM-based quantum sensing and imaging.