Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Applied Physics Letters

Ultrasensitive probing of nematic order parameter via weak measurement

Changyou Wang, Yunhan Wang, Yurong Liu, Tong Li, Lan E Luo, Sijie Zhang, Zhiyou Zhang

Published Jan 20, 2025• 1 citation
Publisher

Abstract

Nematic order parameter S is one of the most crucial material parameters of the nematic phase, which governs all of the material's anisotropic properties. The enhancement of its measurement precision has always been a great concern. In this Letter, a weak measurement scheme with a modified shift pointer is presented to achieve an ultrasensitive probe of S or the director's orientational angle θ. Using this scheme, we have demonstrated a real-time monitoring of the orientational process of cellulose nano-crystal molecules in solutions and measured the orientational direction of polymer nanowires. A typical precision on the order of 10−3 is achieved in the measurement of S and θ. Compared with the current existing techniques, the present scheme not only offers higher measurement precision but also maintains extreme cost-efficiency, thereby holding significance for the research of orientational materials and devices.

DOI
10.1063/5.0250113

Related papers

Ultra-sensitive measurement of third-order optical nonlinearity via weak value amplification

Hongjing Li, Yanjia Li, Jingzheng Huang +2 more

An ultrasensitive third-order optical nonlinearity measurement was theoretically proposed and experimentally demonstrated based on an extended Sagnac interferometer using weak value amplification. The predictable nonlinear refractive index coefficient (n2) of a nonlinear optical sample (nematic liquid crystals) accorded with the experimental result, which confirmed the rationality and feasibility of the proposed method. The sensitivity of the proposed method was associated with the resolution of the spectrometer and the postselection angle. By choosing a currently available spectrometer, the minimum Kerr phase of about 7.5 × 10−7 rad could be measured. Moreover, low cost and convenient operation of this method might have potential application in third-order optical nonlinearity measurements.

Applied Physics Letters•Apr 22, 2019•12 citations

High-precision temperature measurement based on weak measurement using nematic liquid crystals

Hongjing Li, Jingzheng Huang, Yu Yang +3 more

High-precision temperature measurements could guarantee temperature difference control accuracy in research and industrial production. To flexibly achieve high precision and large operating temperature range is a crucial problem for temperature measurements. Here, we demonstrate a method for a high-precision temperature measurement based on a weak measurement done using nematic liquid crystals (NLCs). By performing an analysis in the frequency domain, the temperature variation of NLCs is measured using a Sagnac interferometer with appropriate preselection and postselection. In order to obtain a large operating temperature range, there is a relatively large time delay that resulted from NLCs, and an operational principle is deduced explicitly by Jones matrices. In the proposed method, the precision of 3 × 10−6 °C could be achieved by a currently available spectrometer and the operating temperature range can be modulated by the thickness of NLCs. Moreover, the temperature sensitivity of 13.5 nm/°C could be realized for NLCs with 100 μm thickness, which exhibits at least three orders of magnitude larger than the value for other frequency domain analyses.

Applied Physics Letters•Jun 4, 2018•56 citations

Determination of polarization states of light using the weak measurement with two pointers

Zhaoxue Li, Linguo Xie, Junfan Zhu +2 more

Measuring the polarization state of light has become a challenging study owing to its requirement to simultaneously extract the phase and amplitude parameters with high precision. Here, we present a weak measurement (WM) scheme with two pointers to determine a general polarization state. For the output spectrum from the WM regime, one pointer with the light frequency is used to measure the phase parameter while the other with the post-selected probability is to measure the amplitude. The optimized regime permits the simultaneous measurements of two parameters since the shift results of both two pointers are read in the same working regions. The simulated results show high sensitivity for both two parameters, and high precision that can be comparable with that by other existing schemes. Our scheme can be applied to measure other complex physical effects, providing a method for future ultra-sensitive sensing and metrology.

Applied Physics Express•Sep 3, 2021•3 citations

Precise Measurement of Polarization Variation Using Weak Measurement With Double Pointers

Lan E Luo, Yu He, Junfan Zhu +3 more

In this paper, a weak measurement scheme with double pointers (mean value shift and intensity shift of the post-selected light) is presented to simultaneously measure the tiny polarization change (phase and amplitude) of light in a single experimental apparatus. Furthermore, rather than using charge-coupled-device (CCD) to measure the pointer shift, we use the two-channel photoreceiver combined with lock-in amplifier (LIA) to measure the intensities of a split-Gaussian mode in this work. In this way, we introduce two intensity contrast ratios (ICRs) as special pointers to characterize the mean value and intensity shifts. As a result, the measurement precision of the polarization rotation is on the order of magnitude of$\,10^{-7}rad$in the experiment. These findings provide a distinctive insight into the weak measurement and have important implications for the accurate measurement of complex optical parameters.

IEEE photonics journal•May 31, 2023•5 citations

Weak Measurements in Nano-optics

Niladri Modak, Ankit Kumar Singh, Shyamal Guchhait +3 more

Background: Weak measurement involves weak coupling between the system and the measuring device (pointer) enables large amplification and high precision measurement of small physical parameters. The outcome of this special measurement procedure involving nearly mutually orthogonal pre- and post-selection of states in such weakly interacting systems leads to weak value that can become exceedingly large and lie outside the eigenvalue spectrum of the measured observable. This unprecedented ability of weak value amplification of small physical parameters has been successfully exploited for various metrological applications in the optical domain and beyond. Even though it is a quantum mechanical concept, it can be understood using the classical electromagnetic theory of light and thus can be realized in classical optics. Objective: Here, we briefly review the basic concepts of weak measurement and weak value amplification, provide illustrative examples of its implementation in various optical domains. The applications involve measuring ultra-sensitive beam deflections, high precision measurements of angular rotation, phase shift, temporal shift, frequency shift and so forth, and expand this extraordinary concept in the domain of nano-optics and plasmonics. Methods: In order to perform weak value amplification, we have used Gaussian beam and spectral response as the pointer subsequently. The polarization state associated with the pointer is used as pre and post-selection device. Results: We reveal the weak value amplification of sub-wavelength optical effects namely the Goos-Hänchen shift and the spin hall shift. Further, we demonstrate weak measurements using spectral line shape of resonance as a natural pointer, enabling weak value amplification beyond the conventional limit, demonstrating natural weak value amplification in plasmonic Fano resonances and so forth. The discussed concepts could have useful implications in various nano-optical systems to amplify tiny signals or effects. Conclusion: The emerging prospects of weak value amplification towards the development of novel optical weak measurement devices for metrological applications are extensively discussed.

Current Nanomaterials•Jul 24, 2020•5 citations

Estimation of Kerr angle based on weak measurement with two pointers

Lan E Luo, Tong Li, Yinghang Jiang +3 more

In this paper, we propose a weak measurement method using two pointers to estimate the magneto-optical Kerr angle, which is robust to ellipticity. The double pointers are the amplified displacement shift and intensity of the post-selected light beam, which are the conventional information carried by the light beam and can be directly output by a detector (such as a charge-coupled device). We demonstrate that the product of the double pointers is only related to the phase variation between two basic vectors and independent of the amplitude errors. In the measurement process, when there is an amplitude change or additional amplitude noise between two eigenstates, the product of two pointers is very useful in extracting phase information and shielding amplitude noise. In addition, the product of two pointers has a good linear relationship with the phase variation and a larger dynamic measurement range. This method is applied to measure the magneto-optical Kerr angle of NiFe film. The Kerr angle can be directly obtained using the product of the light intensity and the amplified displacement shift. This scheme is of great significance for the measurement of the Kerr angle of magnetic films.

Optics Express•Apr 3, 2023•13 citations
Nematic order parameter S is one of the most crucial material parameters of the nematic phase, which governs all of the material's anisotropic properties. The enhancement of its measurement precision has always been a great concern. In this Letter, a weak measurement scheme with a modified shift pointer is presented to achieve an ultrasensitive probe of S or the director's orientational angle θ. Using this scheme, we have demonstrated a real-time monitoring of the orientational process of cellulose nano-crystal molecules in solutions and measured the orientational direction of polymer nanowires. A typical precision on the order of 10−3 is achieved in the measurement of S and θ. Compared with the current existing techniques, the present scheme not only offers higher measurement precision but also maintains extreme cost-efficiency, thereby holding significance for the research of orientational materials and devices.
An ultrasensitive third-order optical nonlinearity measurement was theoretically proposed and experimentally demonstrated based on an extended Sagnac interferometer using weak value amplification. The predictable nonlinear refractive index coefficient (n2) of a nonlinear optical sample (nematic liquid crystals) accorded with the experimental result, which confirmed the rationality and feasibility of the proposed method. The sensitivity of the proposed method was associated with the resolution of the spectrometer and the postselection angle. By choosing a currently available spectrometer, the minimum Kerr phase of about 7.5 × 10−7 rad could be measured. Moreover, low cost and convenient operation of this method might have potential application in third-order optical nonlinearity measurements.
High-precision temperature measurements could guarantee temperature difference control accuracy in research and industrial production. To flexibly achieve high precision and large operating temperature range is a crucial problem for temperature measurements. Here, we demonstrate a method for a high-precision temperature measurement based on a weak measurement done using nematic liquid crystals (NLCs). By performing an analysis in the frequency domain, the temperature variation of NLCs is measured using a Sagnac interferometer with appropriate preselection and postselection. In order to obtain a large operating temperature range, there is a relatively large time delay that resulted from NLCs, and an operational principle is deduced explicitly by Jones matrices. In the proposed method, the precision of 3 × 10−6 °C could be achieved by a currently available spectrometer and the operating temperature range can be modulated by the thickness of NLCs. Moreover, the temperature sensitivity of 13.5 nm/°C could be realized for NLCs with 100 μm thickness, which exhibits at least three orders of magnitude larger than the value for other frequency domain analyses.
Measuring the polarization state of light has become a challenging study owing to its requirement to simultaneously extract the phase and amplitude parameters with high precision. Here, we present a weak measurement (WM) scheme with two pointers to determine a general polarization state. For the output spectrum from the WM regime, one pointer with the light frequency is used to measure the phase parameter while the other with the post-selected probability is to measure the amplitude. The optimized regime permits the simultaneous measurements of two parameters since the shift results of both two pointers are read in the same working regions. The simulated results show high sensitivity for both two parameters, and high precision that can be comparable with that by other existing schemes. Our scheme can be applied to measure other complex physical effects, providing a method for future ultra-sensitive sensing and metrology.
In this paper, a weak measurement scheme with double pointers (mean value shift and intensity shift of the post-selected light) is presented to simultaneously measure the tiny polarization change (phase and amplitude) of light in a single experimental apparatus. Furthermore, rather than using charge-coupled-device (CCD) to measure the pointer shift, we use the two-channel photoreceiver combined with lock-in amplifier (LIA) to measure the intensities of a split-Gaussian mode in this work. In this way, we introduce two intensity contrast ratios (ICRs) as special pointers to characterize the mean value and intensity shifts. As a result, the measurement precision of the polarization rotation is on the order of magnitude of 10−7rad\,10^{-7}rad10−7radin the experiment. These findings provide a distinctive insight into the weak measurement and have important implications for the accurate measurement of complex optical parameters.
Background: Weak measurement involves weak coupling between the system and the measuring device (pointer) enables large amplification and high precision measurement of small physical parameters. The outcome of this special measurement procedure involving nearly mutually orthogonal pre- and post-selection of states in such weakly interacting systems leads to weak value that can become exceedingly large and lie outside the eigenvalue spectrum of the measured observable. This unprecedented ability of weak value amplification of small physical parameters has been successfully exploited for various metrological applications in the optical domain and beyond. Even though it is a quantum mechanical concept, it can be understood using the classical electromagnetic theory of light and thus can be realized in classical optics. Objective: Here, we briefly review the basic concepts of weak measurement and weak value amplification, provide illustrative examples of its implementation in various optical domains. The applications involve measuring ultra-sensitive beam deflections, high precision measurements of angular rotation, phase shift, temporal shift, frequency shift and so forth, and expand this extraordinary concept in the domain of nano-optics and plasmonics. Methods: In order to perform weak value amplification, we have used Gaussian beam and spectral response as the pointer subsequently. The polarization state associated with the pointer is used as pre and post-selection device. Results: We reveal the weak value amplification of sub-wavelength optical effects namely the Goos-Hänchen shift and the spin hall shift. Further, we demonstrate weak measurements using spectral line shape of resonance as a natural pointer, enabling weak value amplification beyond the conventional limit, demonstrating natural weak value amplification in plasmonic Fano resonances and so forth. The discussed concepts could have useful implications in various nano-optical systems to amplify tiny signals or effects. Conclusion: The emerging prospects of weak value amplification towards the development of novel optical weak measurement devices for metrological applications are extensively discussed.
In this paper, we propose a weak measurement method using two pointers to estimate the magneto-optical Kerr angle, which is robust to ellipticity. The double pointers are the amplified displacement shift and intensity of the post-selected light beam, which are the conventional information carried by the light beam and can be directly output by a detector (such as a charge-coupled device). We demonstrate that the product of the double pointers is only related to the phase variation between two basic vectors and independent of the amplitude errors. In the measurement process, when there is an amplitude change or additional amplitude noise between two eigenstates, the product of two pointers is very useful in extracting phase information and shielding amplitude noise. In addition, the product of two pointers has a good linear relationship with the phase variation and a larger dynamic measurement range. This method is applied to measure the magneto-optical Kerr angle of NiFe film. The Kerr angle can be directly obtained using the product of the light intensity and the amplified displacement shift. This scheme is of great significance for the measurement of the Kerr angle of magnetic films.