Angular Sensitivity Research Articles

Assessing the potential accuracy of a small-sized goniometer with extended dynamic range based on nuclear magnetic resonance

This paper evaluates potential accuracy characteristics of a small-sized goniometer based on nuclear magnetic resonance with an extended dynamic range. This required constructing a model of goniometer errors, estimating its accuracy based on this model, and formulating practical recommendations for the design of such a device based on the accuracy assessment. To evaluate the accuracy of a nuclear goniometer, a theoretical model was built that makes it possible to determine the optimal operating parameters of the cell gas mixture, the ranges of their permissible changes, the sensitivity of the goniometer, and the dependence of its characteristics on external and internal factors. In particular, the dependence of output signal of the device on the parameters of gas mixture and optical pumping has been determined. For a goniometer with a cell volume of 8 cm3, the optimum temperature is 130 °C, and the optimum intensity of the pumping radiation is 5 mW. The dependence of output signal on the measured angle of rotation was also established, as well as the noise and error dependence of the device on the permissible values of its parameters. Based on the model built, parameters of a goniometer with a cell volume of 8 cm3 were determined; the maximum angular sensitivity of such a goniometer with complete suppression of technical noise is δφsen=1.0 arcsec. The greatest contribution to the angle measurement error is from the instability of pumping power Ip (ΔIp/Ip=0.05) – 85 %, magnetic field B0 (ΔB0/B0=10-8) – 13 %, temperature T (ΔT/T=0,1) – 2 %. The goniometer under consideration corresponds to the medium accuracy class, δφtot≥10 arcsec. It could be used in optical manufacturing for operational control, calibration, and certification of optical products. To improve the angular accuracy of the goniometer, it is necessary to increase the stability of the laser pumping intensity

Dynamical channel coupling in strong-field ionization of CO2

We present a theoretical study employing the time-dependent density functional theory (TDDFT) to explore the effects of angle-resolved channel coupling in strong field ionization of carbon dioxide (CO2) molecules. Our results reveal significant angular sensitivity of both the channel-resolved ionization probabilities and the effects of laser-induced channel couplings. By applying a linearly polarized two-color field scheme, we demonstrate the ability to significantly modify the strength of the laser-induced coupling, evidenced by the changes in the population distributions among the ionic states induced by the strong-field ionization. Importantly, the two-color field optimally modulates the coupling strength at the alignment angle where ionization of the highest occupied molecular orbital (HOMO) electrons is most efficient. This optimization is attributed to the reduction of the electron shielding effect. Our research provides valuable insights into the coherent manipulation of electron distribution within the cation, paving the way for the precise control of ultrafast electron dynamics during strong-field ionization processes.

PEARLS: Discovery of Point-source Features within Galaxies in the North Ecliptic Pole Time Domain Field

The first public 0.9–4.4 μm NIRCam images of the North Ecliptic Pole Time Domain Field uncovered galaxies displaying point-source features in their cores as seen in the longer-wavelength filters. We visually identified a sample of 66 galaxies (∼1 galaxy arcmin–2) with pointlike cores and have modeled their two-dimensional light profiles with GalFit, identifying 16 galactic nuclei with measurable point-source components. GalFit suggests that the visual sample is a mix of both compact stellar bulge and point-source galaxy cores. This core classification is complemented by spectral energy distribution modeling to infer the sample’s active galactic nucleus (AGN) and host-galaxy parameters. For galaxies with measurable point-source components, the median fractional AGN contribution to their 0.1–30.0 μm flux is 0.44, and 14/16 are color-classified AGN. We conclude that near-infrared point-source galaxy cores are signatures of AGN. In addition, we define an automated sample-selection criterion to identify these point-source features. This criterion can be used in other extant and future NIRCam images to streamline the search for galaxies with unresolved IR-luminous AGN. The James Webb Space Telescope’s superb angular resolution and sensitivity at infrared wavelengths are resurrecting the morphological identification of AGN.

Modeling, Calculation and Realization of Au/Nb2O5 Substrates for Surface Plasmon Resonance Sensors

Introduction. Sensor devices based on the surface plasmon resonance (SRP) phenomenon are widely used among the tools of information and diagnostic technologies. The main part of a device based on the surface plasmon resonance phenomenon is a sensor substrate, which consists of a glass plate, a film of plasma-supporting metal, usually gold, and additional layers to increase the sensitivity of the research. Depending on the thickness of the additional dielectric layers, the following types of sensors can be implemented: a conventional SPR sensor with a gold film without a dielectric; an Au/dielectric SPR sensor with a dielectric thickness less than the critical one, in which the system can maintain the plasmonic mode; a waveguide sensor on a metal sublayer, with a dielectric thickness sufficient for the emergence of waveguide modes. The Au/Nb2O5 thin-film system is promising for creating sensor substrates due to the high refractive index of Nb2O5 and its exceptional chemical and mechanical resistance. The purpose of the work. This work is devoted to computer modelling, calculation of performance characteristics and implementation of Au/Nb2O5 sensor substrates for SPR devices, including the Plasmontest series devices developed at the Institute of Cybernetics of the National Academy of Sciences of Ukraine. The behaviour of the characteristics of the SPR substrates with a plasma-supporting gold film, SPR substrates with sensitivity enhancement by an additional layer of Nb2O5 of nanometre thickness and with a waveguide layer of Nb2O5 thickness more than 150 nm are analysed. Calculations were performed for both refractive sensors on SPR and biosensors. Results. The theoretical analysis was carried out by computer modelling in Winspall and calculations in MATLAB using the Fresnel equations and the matrix method, which allowed a comprehensive analysis of the shape of the reflection curves, angular sensitivity, resolution and angular ranges for sensors with different dielectric coatings. It is shown that at a thickness of 0-10 nm, the Au/Nb2O5 structure will work as a SPR sensor with increased sensitivity, and at a thickness of 150-210 nm as a waveguide sensor on a metal sublayer. But, as calculations have shown, only the Au/Nb2O5 SPR sensor is promising for practical implementation to increase the sensitivity of biosensor measurements. The work carried out on the development of thin-film technology, which includes vacuum deposition of a thin-film structure of adhesive Nb (1–2 nm), plasma-supported Au (50 nm), Nb (3–5 nm) and thermal annealing (to oxidise the top layer of niobium), made it possible to implement Au/Nb2O5 substrates for SPR studies. Experimental studies have shown that the angular sensitivity of the Au/Nb2O5 refractometric SPR sensor is 1.5 times higher than that of a SPR sensor with a single Au film at niobium oxide layer thickness of about 6 nm. Thus, the experimentally determined increase in the angular sensitivity of the Au-Nb2O5 SPR sensor is consistent with the theoretical data. Conclusions. Calculations have shown an increase in the angular sensitivity of SPR sensors for Au/Nb2O5 sensor substrates compared to conventional Au film substrates for both refractometric (1.6 times) and biosensor (1.8 times) studies. The sensors on Au/Nb2O5 substrates for SPR studies, which we have designed and practically implemented, are cheap to manufacture, have higher sensitivity, and due to the exceptional chemical and mechanical stability of Nb2O5, can be used repeatedly in rather aggressive environments. Keywords: computer modelling, surface plasmon resonance, sensor, refractometer, biosensor.

Demonstration of in-vivo simultaneous 3D imaging with 18F-FDG and Na131I using Compton–PET system

Simultaneous imaging of the SPECT tracer 131I and PET tracer 18F is important in the diagnosis of high- and low-grade thyroid cancers because high-grade thyroid cancers have high 18F-FDG and low 131I uptake, while low-grade thyroid cancers have high 131I and low 18F-FDG uptake. In this study, Na131I and 18F-FDG were simultaneously imaged using the Compton-PET system, in vivo. The angular resolution and sensitivity of the Compton camera with 356 keV gamma ray measured using a 133Ba point source were 12.3° and 2 × 10−5, respectively. The spatial resolution and sensitivity of PET were measured with a 22Na point source. The transaxial and axial spatial resolutions of the PET at the center of the FOV were 1.15 mm and 2.04 mm, respectively. Its sensitivity was 1.2 × 10−4. In-vivo images of the 18F and 131I isotopes were simultaneously acquired from mice. These showed that 18F-FDG was active in the heart, brown fat, and brain, while Na131I was active in the thyroid, stomach, and bladder. Artifacts were found in the Compton camera images when the activity of 131I was much lower than that of 18F. This study demonstrates the potential of simultaneous clinical imaging of 18F and 131I.

An ultra broadband metamaterial absorber based on metal-dielectric-metal technology for THz spectrum

This paper introduces a novel ultra-broadband Metamaterial Absorber (UBMA) demonstrating significant absorption capabilities across a wide terahertz frequency range from 2.42 THz to 6.11 THz. The 3.7 THz bandwidth represents 87% of the central frequency. The proposed UBMA comprises three layers: a star-shaped metal patch on top, a dielectric substrate in the middle, and a metallic ground plane below. Simulations using CST Microwave Studio software reveal that the design achieves high absorption at five distinct frequencies: 2.47, 3.45, 4.89, 6.01, and 6.87 THz, with absorption rates of 99% for the first four peaks and 90% for the fifth peak. The study of electric field and surface current distribution provides insights into the absorption mechanism. While the UBMA exhibits polarization-independent performance, its angular response shows some sensitivity to the incident angle, especially beyond 30° Despite this, the absorber maintains over 70% absorptivity up to a 45° incidence angle for both TE and TM polarizations within specific frequency ranges. The simple structure combined with high absorption efficiency makes the UBMA suitable for THz imaging, detection, and stealth applications, although its angular sensitivity must be considered for certain applications.

ALMA follow-up of ∼ 3000 red-Herschel galaxies: The nature of extreme submillimeter galaxies

Abstract We present the analysis of over 3000 red-Herschel sources ($S_{\mathrm{250\, \mu m}}<S_{\mathrm{350\, \mu m}}<S_{\mathrm{500\, \mu m} }$) using public data from the ALMA archive and the Herschel-ATLAS survey. This represents the largest sample of red-Herschel sources with interferometric follow-up observations to date. The high ALMA angular resolution and sensitivity (θFWHM ∼1 arcsecond; σ1.3 mm ∼ 0.17 mJy beam−1) allow us to classify the sample into individual sources, multiple systems, and potential lenses and/or close mergers. Interestingly, even at this high angular resolution, 73 per cent of our detections are single systems, suggesting that most of these galaxies are isolated and/or post-merger galaxies. For the remaining detections, 20 per cent are classified as multiple systems, 5 per cent as lenses and/or mergers, and 2 per cent as low-z galaxies or Active Galactic Nuclei. Combining the Herschel/SPIRE and ALMA photometry, these galaxies are found to be extreme and massive systems with a median star formation rate of ∼1500 M⊙ yr−1 and molecular gas mass of Mgas ∼ 1011 M⊙. The median redshift of individual sources is z ≈ 2.8, while the likely lensed systems are at z ≈ 3.3, with redshift distributions extending to z ∼ 6. Our results suggest a common star-formation mode for extreme galaxies across cosmic time, likely triggered by close interactions or disk-instabilities, and with short depletion times consistent with the starburst-type population. Moreover, all galaxies with S1.3mm ≥ 13 mJy are gravitationally amplified which, similar to the established $S_{500\mathrm{ \, \mu m}}>100$ mJy threshold, can be used as a simple criterion to identify gravitationally lensed galaxies.

Scalable Bayesian uncertainty quantification with data-driven priors for radio interferometric imaging

Abstract Next-generation radio interferometers like the Square Kilometer Array have the potential to unlock scientific discoveries thanks to their unprecedented angular resolution and sensitivity. One key to unlocking their potential resides in handling the deluge and complexity of incoming data. This challenge requires building radio interferometric (RI) imaging methods that can cope with the massive data sizes and provide high-quality image reconstructions with uncertainty quantification (UQ). This work proposes a method coined QuantifAI to address UQ in RI imaging with data-driven (learned) priors for high-dimensional settings. Our model, rooted in the Bayesian framework, uses a physically motivated model for the likelihood. The model exploits a data-driven convex prior potential, which can encode complex information learned implicitly from simulations and guarantee the log-concavity of the posterior. We leverage probability concentration phenomena of high-dimensional log-concave posteriors to obtain information about the posterior, avoiding MCMC sampling techniques. We rely on convex optimisation methods to compute the MAP estimation, which is known to be faster and better scale with dimension than MCMC strategies. QuantifAI allows us to compute local credible intervals and perform hypothesis testing of structure on the reconstructed image. We propose a novel fast method to compute pixel-wise uncertainties at different scales, which uses 3 and 6 orders of magnitude less likelihood evaluations than other UQ methods like length of the credible intervals and Monte Carlo posterior sampling, respectively. We demonstrate our method by reconstructing RI images in a simulated setting and carrying out fast and scalable UQ, which we validate with MCMC sampling. Our method shows an improved image quality and more meaningful uncertainties than the benchmark method based on a sparsity-promoting prior. QuantifAI’s source code is available from https://github.com/astro-informatics/QuantifAI.

Spatial resolution and optical sensitivity in the compound eyes of two common European wasps, Vespula germanica and Vespula vulgaris.

Vespula germanica and Vespula vulgaris are two common European wasps that have ecological and economic importance as a result of their artificial introduction into many different countries and environments. Their success has undoubtedly been aided by their capacity for visually guided hunting, foraging, learning and using visual cues in the context of homing and navigation. However, the visual systems of V. germanica and V. vulgaris have not received any deep attention. We used electrophysiology, together with optical and anatomical techniques, to measure the spatial resolution and optical sensitivity of the compound eyes of both species. We found that both wasps have high anatomical spatial resolution with narrow interommatidial angles (Δϕ between 1.0 and 1.5deg) and a distinct acute zone in the fronto-ventral part of the eye. These narrow interommatidial angles are matched to photoreceptors having narrow angular sensitivities (acute zone acceptance angles Δρ below 1.3deg), indicating eyes of high spatial resolution that are well suited to their ecological needs. Additionally, we found that both species possess an optical sensitivity that is typical of other day-flying hymenopterans.

High-angular-sensitivity X-ray phase-contrast microtomography of soft tissue through a two-directional beam-tracking synchrotron set-up.

Two-directional beam-tracking (2DBT) is a method for phase-contrast imaging and tomography that uses an intensity modulator to structure the X-ray beam into an array of independent circular beamlets that are resolved by a high-resolution detector. It features isotropic spatial resolution, provides two-dimensional phase sensitivity, and enables the three-dimensional reconstructions of the refractive index decrement, δ, and the attenuation coefficient, μ. In this work, the angular sensitivity and the spatial resolution of 2DBT images in a synchrotron-based implementation is reported. In its best configuration, angular sensitivities of ∼20 nrad and spatial resolution of at least 6.25 µm in phase-contrast images were obtained. Exemplar application to the three-dimensional imaging of soft tissue samples, including a mouse liver and a decellularized porcine dermis, is also demonstrated.

PHANGS-JWST: Data-processing Pipeline and First Full Public Data Release

The exquisite angular resolution and sensitivity of JWST are opening a new window for our understanding of the Universe. In nearby galaxies, JWST observations are revolutionizing our understanding of the first phases of star formation and the dusty interstellar medium. Nineteen local galaxies spanning a range of properties and morphologies across the star-forming main sequence have been observed as part of the PHANGS-JWST Cycle 1 Treasury program at spatial scales of ∼5–50 pc. Here, we describe pjpipe, an image-processing pipeline developed for the PHANGS-JWST program that wraps around and extends the official JWST pipeline. We release this pipeline to the community as it contains a number of tools generally useful for JWST NIRCam and MIRI observations. Particularly for extended sources, pjpipe products provide significant improvements over mosaics from the MAST archive in terms of removing instrumental noise in NIRCam data, background flux matching, and calibration of relative and absolute astrometry. We show that slightly smoothing F2100W MIRI data to 0.″9 (degrading the resolution by about 30%) reduces the noise by a factor of ≈3. We also present the first public release (DR1.1.0) of the pjpipe processed eight-band 2–21 μm imaging for all 19 galaxies in the PHANGS-JWST Cycle 1 Treasury program. An additional 55 galaxies will soon follow from a new PHANGS-JWST Cycle 2 Treasury program.

Sp1149. I. Constraints on the Balmer L–σ Relation for H ii Regions in a Spiral Galaxy at Redshift z = 1.49 Strongly Lensed by the MACS J1149 Cluster

The luminosities (L) and velocity dispersions (σ) of the extinction-corrected Balmer emission lines of giant H ii regions in nearby galaxies exhibit a tight correlation (∼0.35 dex scatter). There are few constraints, however, on whether giant H ii regions at significant look-back times follow an L–σ relation, given the angular resolution and sensitivity required to study them individually. We measure the luminosities and velocity dispersions of Hα and Hβ emission from 11 H ii regions in Sp1149, a spiral galaxy at redshift (z) z = 1.49 multiply imaged by the MACS J1149 galaxy cluster. Sp1149 is also the host galaxy of the first-known strongly lensed supernova with resolved images, SN Refsdal. We employ archival Keck I OSIRIS observations, and newly acquired Keck I MOSFIRE and Large Binocular Telescope LUCI long-slit spectra of Sp1149. When we use the GLAFIC simply parameterized lens model, we find that the Hα luminosities of the H ii regions at z = 1.49 are a factor of 6.4−2.0+2.9 brighter than predicted by the low-redshift L–σ relation we measure from Very Large Telescope MUSE spectroscopy. If the lens model is accurate, then the H ii regions in Sp1149 differ from their low-redshift counterparts. We identify an H ii region in Sp1149 that is dramatically brighter (by 2.03 ± 0.44 dex) than our low-redshift L–σ relation predicts given its low velocity dispersion. Finally, the H ii regions in Sp1149 are consistent, perhaps surprisingly, with the z ≈ 0 star-forming locus on the Baldwin–Phillips–Terlevich diagram.

Angular momentum sensitivities in scalar-tensor theories

Angular momentum sensitivities in scalar-tensor theories

Wavelength-Dependent Angular Sensitivity Signatures in SPR Sensors: Is the 633 nm Wavelength Still Optimal for the Latest Designs?

Wavelength-Dependent Angular Sensitivity Signatures in SPR Sensors: Is the 633 nm Wavelength Still Optimal for the Latest Designs?

An arcsecond view at 1–2 GHz into the Galactic Bulge

ABSTRACT We present the results of a high angular resolution (1.1 arcsec) and sensitivity (maximum of ∼0.1 mJy) radio survey at 1–2 GHz in the Galactic Bulge. This complements the X-ray Chandra Galactic Bulge Survey, and investigates the full radio source population in this dense Galactic region. Radio counterparts to sources at other wavelengths can aid in classification, as there are relatively few types of objects that are reasonably detectable in radio at kiloparsec distances, and even fewer that are detected in both X-rays and radio. This survey covers about 3 sq deg of the Galactic Bulge Survey area (spanning the Galactic coordinate range of −3° < l < +3° and +1.6° < b < +2.1°) as a first look into this region of the Galaxy with this combination of frequency, resolution, and sensitivity. Spectral indices within the observed band of 1–2 GHz were calculated for each source to assist in determining its emission mechanism. We find 1617 unique sources in the survey, 25 of which are radio counterparts to X-ray sources, and about 100 of which are steep-spectrum (α ≲ −1.4) point sources that are viable pulsar candidates. Four radio sources are of particular interest: a compact binary; an infrared transient with an inverted radio spectrum; a potential transitional millisecond pulsar candidate; and a very steep spectrum radio source with an X-ray and bright infrared counterpart. We discuss other notable sources, including possible radio transients, potential new planetary nebulae, and active galactic nuclei.

Complexity of many-body interactions in transition metals via machine-learned force fields from the TM23 data set

This work examines challenges associated with the accuracy of machine-learned force fields (MLFFs) for bulk solid and liquid phases of d-block elements. In exhaustive detail, we contrast the performance of force, energy, and stress predictions across the transition metals for two leading MLFF models: a kernel-based atomic cluster expansion method implemented using sparse Gaussian processes (FLARE), and an equivariant message-passing neural network (NequIP). Early transition metals present higher relative errors and are more difficult to learn relative to late platinum- and coinage-group elements, and this trend persists across model architectures. Trends in complexity of interatomic interactions for different metals are revealed via comparison of the performance of representations with different many-body order and angular resolution. Using arguments based on perturbation theory on the occupied and unoccupied d states near the Fermi level, we determine that the large, sharp d density of states both above and below the Fermi level in early transition metals leads to a more complex, harder-to-learn potential energy surface for these metals. Increasing the fictitious electronic temperature (smearing) modifies the angular sensitivity of forces and makes the early transition metal forces easier to learn. This work illustrates challenges in capturing intricate properties of metallic bonding with current leading MLFFs and provides a reference data set for transition metals, aimed at benchmarking the accuracy and improving the development of emerging machine-learned approximations.

Analysis and Compensation of Lorentz Force Magnetic Bearing Magnetic Flux Density Uniformity Error.

Aiming at the influence of the magnetic flux density uniformity error (MFDUE) of the Lorentz force magnetic bearing (LFMB) on the sensitivity accuracy of magnetically suspended control and sensing gyroscopes (MSCSGs) on the angular rate of a spacecraft, a high precision measurement method of the angular rate of a spacecraft based on the MFDUE compensation of LFMB is proposed. Firstly, the structure of MSCSG and the sensitivity principle of MSCSG to the spacecraft angular rate are introduced. The mechanism influencing the accuracy of MSCSG to spacecraft angular rate sensitivity is deduced based on the definition of magnetic flux density uniformity. Secondly, the 3D magnetic flux distribution of LFMB is analyzed using ANSYS. The relationship between the rotor tilt angle, tilt angular rate, and magnetic flux density is established. The induced current calculation model due to MFDUE is proposed, and the LFMB magnetic flux density error compensation is realized. Finally, the simulation results show that the estimation accuracy of the induced current by the proposed method can reach 96%, and the simulation and the experiment show that the error compensation method can improve the accuracy of MSCSG in measuring the spacecraft angular rate by 12.5%.

Lossy Mode Resonance Sensors Based on Anisotropic Few-Layer Black Phosphorus.

Lossy mode resonance (LMR) sensors offer a promising avenue to surpass the constraints of conventional surface plasmon resonance (SPR) sensors by delivering enhanced label-free detection capabilities. A notable edge of LMR over SPR is its excitation potential by both transverse electric (TE) and transverse magnetic (TM) polarized light. Yet this merit remains underexplored due to challenges to achieving high sensing performance under both TM and TE polarization within a singular LMR model. This study introduces a theoretical model for an LMR prism refractive index sensor based on a MgF2-few layer black phosphorus-MgF2 configuration, which can achieve angular sensitivity nearing 90° refractive index unit-1 (RIU-1) for both polarizations. Leveraging the distinct anisotropic nature of black phosphorus, the figure of merit (FOM) values along its two principal crystal axes (zigzag and armchair) show great difference, achieving an impressive FOM of 1.178 × 106 RIU-1 along the zigzag direction under TE polarized light and 1.231 × 104 RIU-1 along the armchair direction under TM polarized light. We also provide an analysis of the electric field distribution for each configuration at its respective resonant conditions. The proposed structure paves the way for innovative applications of anisotropic-material-based LMR sensors in various applications.

The viability of low-mass subhaloes as targets for gamma-ray dark matter searches

ABSTRACT In this work, we investigate the discovery potential of low-mass Galactic dark matter (DM) subhaloes for indirect searches of DM. We use data from the Via Lactea II (VL-II) N-body cosmological simulation, which resolves subhaloes down to $\mathcal {O}(10^4)$ solar masses and it is thus ideal for this purpose. First, we characterize the abundance, distribution and structural properties of the VL-II subhalo population in terms of both subhalo masses and maximum circular velocities. Then, we repopulate the original simulation with millions of subhaloes of masses down to about five orders of magnitude below the minimum VL-II subhalo mass (more than one order of magnitude in velocities). We compute subhalo DM annihilation astrophysical ‘J-factors’ and angular sizes for the entire subhalo population, by placing the Earth at a random position but at the right Galactocentric distance in the simulation. Thousands of these realizations are generated in order to obtain statistically meaningful results. We find that some nearby low-mass Galactic subhaloes, not massive enough to retain stars or gas, may indeed yield DM annihilation fluxes comparable to those expected from other, more massive and acknowledgeable DM targets like dwarf satellite galaxies. Typical angular sizes are of the order of the degree, thus subhaloes potentially appearing as extended sources in gamma-ray telescopes, depending on instrument angular resolution and sensitivity. Our work shows that low-mass Galactic subhaloes with no visible counterparts are expected to play a relevant role in current and future indirect DM search searches and should indeed be considered as excellent DM targets.

A self-referenced interferometer for in situ cryogenic wafer curvature measurements.

A self-referenced interferometer to measure time-varying curvature in mechanically unstable environments is needed in many applications. One application that demands this measurement technique with fast data acquisition, 2D sensitivity, and insensitivity to vibration is the measurement of thermal strain in thin films in operational environments. The diverging beam interferometer described here demonstrates an angular sensitivity to the local curvature using interferograms captured by a CMOS camera. Two-dimensional Fourier analysis is used to extract curvature changes. The interferometer demonstrates an experimental sensitivity to curvature changes on the order of 10-4 m-1 and is used to measure thermal stresses in a cryogenic environment of a polycrystalline titanium nitride thin film on a silicon wafer that exhibits anisotropic curvature.