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With the ultra-thin thickness and excellent performance, metalens are bi-dimensional optical elements composed of nanopatterned structures that demonstrate significant potential for various applications such as holography, planar imaging and tomography. However, the small size of metalens makes it challenging to precisely quantify their wavefront aberration, thus impeding their broader utilization. To address this challenge, we propose an innovative method for measuring wavefront aberration in metalens using phase-shift interferometry. Furthermore, we have developed the Small Aperture Interferometric Imaging Detection System with variable fields of view, specifically designed for metalens. This system can accurately measure the wavefront aberration of metalens with different fields of view with PV accuracy of 1/20λ, further enabling the acquisition of imaging performance parameters, including Modulation Transfer Function (MTF) and Point Spread Function (PSF). This innovative measurement approach not only enables quantitative evaluation of performance of metalens but also assists designers and manufacturers in optimizing process flows and identifying potential defects. As a result, this approach aids in promoting the industrial application of metalens.

With the ultra-thin thickness and excellent performance, metalens are bi-dimensional optical elements composed of nanopatterned structures that demonstrate significant potential for various applications such as holography, planar imaging and tomography. However, the small size of metalens makes it challenging to precisely quantify their wavefront aberration, thus impeding their broader utilization. To address this challenge, we propose an innovative method for measuring wavefront aberration in metalens using phase-shift interferometry. Furthermore, we have developed the Small Aperture Interferometric Imaging Detection System with variable fields of view, specifically designed for metalens. This system can accurately measure the wavefront aberration of metalens with different fields of view with PV accuracy of 1/20λ, further enabling the acquisition of imaging performance parameters, including Modulation Transfer Function (MTF) and Point Spread Function (PSF). This innovative measurement approach not only enables quantitative evaluation of performance of metalens but also assists designers and manufacturers in optimizing process flows and identifying potential defects. As a result, this approach aids in promoting the industrial application of metalens. [ABSTRACT FROM AUTHOR]

The SPR phenomenon results in an abrupt change in the optical phase such that one can measure the phase shift of the reflected light as a sensing parameter. Moreover, many studies have demonstrated that the phase changes more acutely than the intensity, leading to a higher sensitivity to the refractive index change. However, currently, the optical phase cannot be measured directly because of its high frequency; therefore, investigators usually have to use complicated techniques for the extraction of phase information. In this study, we propose a simple and effective strategy for measuring the SPR phase shift based on phase-shift interferometry. In this system, the polarization-dependent interference signals are recorded simultaneously by a pixelated polarization camera in a single snapshot. Subsequently, the phase information can be effortlessly acquired by a phase extraction algorithm. Experimentally, the proposed phase-sensitive SPR sensor was successfully applied for the detection of small molecules of glyphosate, which is the most frequently used herbicide worldwide. Additionally, the sensor exhibited a detection limit of 15 ng/mL (0.015 ppm). Regarding its simplicity and effectiveness, we believe that our phase-sensitive SPR system presents a prospective method for acquiring phase signals.

Abstract: One important source of error in phase-shift interferometry consists of a nonuniform application of phase steps, due, for example, to a nonlinear piezoelectric effect in the phase shifter. We developed a method for inline PZT calibration using a video camera for acquiring interferograms and an ATI Radeon X1650 video card for frame processing. The PZT was calibrated over a voltage range of 40V and a displacement range of 11μm. We acquired 801 interferograms in a Twyman-Green interferometer and a 801×801 matrix computed from the subtraction of each interferogram from every other interferogram was obtained and used for calibration. The speed and accuracy of frame processing of the video card was compared to the results obtained by an Intel QuadCore processor. In terms of accuracy there are no significant differences, but the processing using the video card was ∼5 times faster than the processing using the processor. The processing took ∼5min and we obtained a dispersion of ∼10nm when we fitted the displacement of the PZT to a polynomial of degree 5 in voltage. [Copyright &y& Elsevier]

Abstract: The use of wavelength-shifting interferometry with a He–Ne laser source is presented. The approach is based on the thermal expansion of the laser cavity during the warm-up time, in conjunction with an unequal path interferometric configuration. The optics principles are reviewed, and a demonstrative measurement is presented. The technique extends the capability of phase-shift acquisition and processing to cases where conventional methods with piezoelectric transducers cannot be used, and particularly to external measurement cavities of large diameter. [Copyright &y& Elsevier]

Abstract: For the long-term assessment of CO2 geological sequestration, the dissolution rate of feldspar was measured under various degrees of saturation based on observations of the time-course change of dissolved crystal surfaces on a nanoscale. We identified that the dependence of solution saturation state on anorthite dissolution rate follows to a L-shaped function, rather than to a linear function. Compared with a linear assumption, such a nonlinear form provides a much lower estimate of dissolution rate. This implies that the difference of rate formula can cause meaningful errors in the timescale evaluation of various geochemical processes. In this study, therefore, the effect of the function form of dissolution rate was also checked using the geochemical simulation code to analyze CO2 geological sequestration. [Copyright &y& Elsevier]

Compression and encryption/decryption are necessary for secure and efficient storage and transmission of image data. Optical encryption, as a promising application of display devices, takes advantage of both the massive parallelism inherent in optical systems and the flexibility offered by digital electronics. We encrypt real-world three-dimensional (3D) objects, captured using phase-shift interferometry, by combining a phase mask and Fresnel propagation. Compression is achieved by nonuniformly quantizing the complex-valued encrypted digital holograms using an artificial neural network. Decryption is performed by displaying the encrypted hologram and phase mask in an identical configuration. We achieved good quality decryption and reconstruction of 3D objects with as few as 2 bits in each real and imaginary value of the encrypted data [ABSTRACT FROM PUBLISHER]

The dissolution behavior of the (101) plane of zircon mineral in ultrapure water, 1 M HCl (aq), and 1 M NaOH (aq), under room temperature and nearly atmospheric pressure was evaluated by in situ measurement of the change in the surface height. A high-resolution phase-shift interferometry microscope (HR-PSI) was employed to evaluate the velocity of the change in the surface height of zircon in different solutions, and the application of this method in evaluating the dissolution behavior of nuclear materials was examined. In all cases, the measured surface height decreased linearly with small variations. Although the measured change in height of zircon in 1 M NaOH (aq) was the smallest under these conditions, the concentration of dissolved Zr in NaOH (aq) was two orders of magnitude higher than that in ultrapure water. This indicates that a high amount of dissolved Zr in 1 M NaOH (aq) was immediately precipitated on the zircon surface as a secondary phase, and the surface shape was almost retained. On the other hand, the precipitation on the reference of the surface height was confirmed while measuring the zircon in 1 M HCl (aq). This shows that the precipitation in 1 M HCl (aq) occurred far from the dissolution points, and the surface shape changed. As a result, the velocity of surface change and the precipitation behavior of zircon, which is one of the extremely durable minerals, was successfully evaluated using HR-PSI. This relatively quick method would be useful for evaluating the detailed surface change behaviors of nuclear materials, such as fuel debris, ceramic waste forms, and UO 2 , during the reaction with various solutions, since it minimises radiation exposure times and also the amount of radioactive waste generation during measurement. [ABSTRACT FROM AUTHOR]

The SPR phenomenon results in an abrupt change in the optical phase such that one can measure the phase shift of the reflected light as a sensing parameter. Moreover, many studies have demonstrated that the phase changes more acutely than the intensity, leading to a higher sensitivity to the refractive index change. However, currently, the optical phase cannot be measured directly because of its high frequency; therefore, investigators usually have to use complicated techniques for the extraction of phase information. In this study, we propose a simple and effective strategy for measuring the SPR phase shift based on phase-shift interferometry. In this system, the polarization-dependent interference signals are recorded simultaneously by a pixelated polarization camera in a single snapshot. Subsequently, the phase information can be effortlessly acquired by a phase extraction algorithm. Experimentally, the proposed phase-sensitive SPR sensor was successfully applied for the detection of small molecules of glyphosate, which is the most frequently used herbicide worldwide. Additionally, the sensor exhibited a detection limit of 15 ng/mL (0.015 ppm). Regarding its simplicity and effectiveness, we believe that our phase-sensitive SPR system presents a prospective method for acquiring phase signals. [ABSTRACT FROM AUTHOR]

A Stroboscopic phase-shift interferometry has been developed to visualize surface acoustic wave (SAW) propagation on SAW devices quantitatively. The developed interferometry is a Fizeau-type one with a multi-mode semiconductor laser diode and an optical isolator. With the laser light illuminating stroboscopically, observed interference intensity gives information about average displacements of the vibrations. Fifty MHz SAW propagation on the surface of the SAW device has been measured with the interferometry. Distribution of the SAW along the propagation path has been observed, whose amplitude is 3 nm (p-p). Repetition accuracy evaluated with the root mean square method is 1/2500 of the laser wavelength. The system is useful for estimating and improving performances of micro-devices. [ABSTRACT FROM AUTHOR]

Abstract: The phase-shift interferometry combined with surface plasmon resonance (SPR) effect has been studied as a novel technique used to analyze the bio-surface, which measures the spatial phase variation of SPR reflected light. The spatial sensitivity of the SPR imaging sensor is improved over the conventional SPR imaging systems based on optical intensity. [Copyright &y& Elsevier]

The Gibbs free energy change, ΔGr, dependence of the anorthite dissolution rate in a supercritical CO2-water system was measured as part of a geochemical assessment of CO2 geological sequestration. Being bounded at ΔGrcrit, the critical ΔGr required for an opening of the etch pit at a screw dislocation, it has been accepted that mineral dissolution follows etch pit formation assisted by dislocations below ΔGrcrit, whereas the horizontal step retreats without the etch pit above ΔGrcrit. The experiment described herein, however, revealed that another mode of dissolution occurs more distant from equilibrium by spontaneous formation of the etch pit over the entire surface, as observed on calcite. The dissolution rate is higher by more than one order of magnitude than that in the dislocation-assisted mode. Therefore, including the rate gap at ΔGrcrit, a nonlinear curve with three steps instead of a sigmoidal curve is proposed for the ΔGr dependence of the anorthite dissolution rate. Extremely slow rates were observed depending on observed points for the same ΔGr condition. Although the reason for such a rate difference remains unknown, it is likely related to the defect density on the crystal surface. It is possible that initial spreading of the dissolved surface attributable to the etch pit formation assisted by defects provides some trigger for subsequent explosive etch pit formation. These findings suggest that the initial transient process can strongly influence the kinetics of geochemical reactions that occur during CO2 geological sequestration. [ABSTRACT FROM AUTHOR]