Quantum measurements have been intensively researched over decades due to quantum advantage of Heisenberg limit beating the standard quantum limit toward potential applications of quantum metrology. The kernel of quantum measurements is in the quantum correlation between bipartite photon pairs or squeezed light quenched by one parameter over corresponding noncommuting variable satisfying Heisenberg uncertainty principle. As a result, quantum measurements bring a quantum gain of the square root law in measurement sensitivity. Photonic de Broglie waves (PBW) have been the key feature of such a gain in quantum metrology especially for phase resolution enhancement beyond the classical limit of Rayleigh criterion or simply the diffraction limit. Due to extremely low efficiency of higher-order entangled photon pair generations such as a NOON state, however, the implementation of PBW for quantum metrology has been severely limited. Here, a completely different mechanism of quantum measurements is introduced for a new type of PBW and presented for its potential application of a modified Sagnac interferometer, where the resolution enhancement is several orders of magnitude higher than its classical counterpart.
Quantum measurements have been intensively researched over decades due to quantum advantage of Heisenberg limit beating the standard quantum limit toward potential applications of quantum metrology. The kernel of quantum measurements is in the quantum correlation between bipartite photon pairs or squeezed light quenched by one parameter over corresponding noncommuting variable satisfying Heisenberg uncertainty principle. As a result, quantum measurements bring a quantum gain of the square root law in measurement sensitivity. Photonic de Broglie waves (PBW) have been the key feature of such a gain in quantum metrology especially for phase resolution enhancement beyond the classical limit of Rayleigh criterion or simply the diffraction limit. Due to extremely low efficiency of higher-order entangled photon pair generations such as a NOON state, however, the implementation of PBW for quantum metrology has been severely limited. Here, a completely different mechanism of quantum measurements is introduced for a new type of PBW and presented for its potential application of a modified Sagnac interferometer, where the resolution enhancement is several orders of magnitude higher than its classical counterpart.
Quantum measurements have been intensively researched over decades due to quantum advantage of Heisenberg limit beating the standard quantum limit toward potential applications of quantum metrology. The kernel of quantum measurements is in the quantum correlation between bipartite photon pairs or squeezed light quenched by one parameter over corresponding noncommuting variable satisfying Heisenberg uncertainty principle. As a result, quantum measurements bring a quantum gain of the square root law in measurement sensitivity. Photonic de Broglie waves (PBW) have been the key feature of such a gain in quantum metrology especially for phase resolution enhancement beyond the classical limit of Rayleigh criterion or simply the diffraction limit. Due to extremely low efficiency of higher-order entangled photon pair generations such as a NOON state, however, the implementation of PBW for quantum metrology has been severely limited. Here, a completely different mechanism of quantum measurements is introduced for a new type of PBW and presented for its potential application of a modified Sagnac interferometer, where the resolution enhancement is several orders of magnitude higher than its classical counterpart.
Photonic de Broglie waves (PBWs) via two-mode entangled photon pair interactions on a beam splitter show a pure quantum feature which cannot be obtained by classical means1-4. Although PBWs have been intensively studied for quantum metrology5-13 and quantum sensing14-25 over the last several decades, their implementation has been limited due to difficulties of high-order NOON state generation4. Recently a coherence version of PBWs, the so-called coherence de Broglie waves (CBWs), has been proposed in a pure classical regime of an asymmetrically coupled Mach-Zehnder interferometer (MZI)26. Unlike PBWs, the quantumness of CBWs originates from the cascaded quantum superposition of the coupled MZI. Here, the first CBWs observation is presented in a pure classical regime and discussed for its potential applications in coherence quantum metrology to overcome conventional PBWs limited by higher-order entangled photons. To understand the quantum superposition-based nonclassical features in CBWs, various violation tests are also performed, where asymmetrical phase coupling is the key parameter for CBWs.
In sensors, the highest precision in measurements is given by vacuum fluctuations of quantum mechanics, resulting in a shot noise limit. In a Mach-Zenhder interferometer (MZI), the intensity measurement is correlated with the phase, and thus, the precision measurement (Δn) is coupled with the phase resolution (Δφ) by the Heisenberg uncertainty principle. Quantum metrology offers a different solution to this precision measurement using nonclassical light such as squeezed light or higher-order entangled-photon pairs, resulting in a smaller Δφ and sub-shot noise limit. Here, we propose another method for the high precision measurement overcoming the diffraction limit in classical physics, where the smaller Δφ is achieved by phase quantization in a coupled interferometric system of coherence de Broglie waves. For a potential application of the proposed method, a quantum ring laser gyroscope is presented as a quantum version of the conventional ring laser gyroscope used for inertial navigation and geodesy.
In a Mach-Zenhder interferometer (MZI), the highest precision for a measurement error is given by vacuum fluctuations of quantum mechanics, resulting in a shot noise limit1,2,3,4,5. Because the intensity measurement in an MZI is correlated with the phase difference, the precision measurement (Δn) is coupled with the phase resolution (Δϕ) by the Heisenberg uncertainty principle. Quantum metrology offers a different solution to this precision measurement using nonclassical light such as squeezed light or higher-order entangled-photon pairs, resulting in a smaller Δϕ for the same Δn3,4,5,6,7,8. Here, we propose another method for the high precision measurement overcoming the Heisenberg photon-phase relation, where the smaller Δϕ is achieved by phase quantization in a coupled interferometric system via coherence de Broglie waves (CBWs)9,10. For a potential application of the proposed method, a quantum ring gyroscope is presented as a quantum version of the conventional ring laser gyroscope used for inertial navigation and geodesy11-13.
A Sagnac interferometer has been a powerful tool for gyroscope, spectroscopy, and navigation based on the Sagnac effects between counterpropagating twin fields in a closed loop, whose difference phase is caused by Einstein’s special relativity. Here, a nonclassical version of a Sagnac interferometer is presented using completely different physics of coherence de Broglie waves (CBW) in a cavity, where CBW is a nonclassical feature overcoming the standard quantum limit governed by classical physics.
Interferometer-based precision measurements have been intensively studied for sensing and metrology over the past half century. In classical optics, the resolution and phase sensitivity of an optical signal are confined by diffraction limit and shot-noise limit (SNL), respectively. Highly entangled photon pairs, i.e., N00N states have been adapted to overcome SNL in quantum sensing over the last two decades. Recently, coherent light-excited quantum sensing has also been proposed and demonstrated for macroscopic quantum sensing to overcome the limited N scalability in N00N-based quantum sensing. Here, a Sagnac interferometer-based superresolution is proposed to solve environmental noises inevitable in an interferometer. Furthermore, a spatial light modulator takes over the role of phase-controlled quantum erasers to solve the linear optics-based complexity issue in the coherently-excited superresolution. Thus, the proposed Sagnac superresolution can beat the state-of-the-art ring laser gyroscope applied for inertial navigation and geodesy.