arXiv subjects

Michael Crescimanno

Publications and source records attributed to Michael Crescimanno.

At least 19 recordsLinked to original sources

arXiv2025

All-Optical Photoluminescence Response of Nitrogen-Vacancy Ensembles in Diamond at Low Magnetic Fields

All-optical (AO), microwave-free magnetometry using nitrogen-vacancy (NV) centers in diamond is attractive due to its broad sample compatibility and reduced experimental complexity. In this work, we investigate room-temperature AO photoluminescence (PL) at low magnetic fields (<2 mT) using diamonds with NV ensembles at ppm concentrations. Measured AO-PL contrast features as a function of applied magnetic field magnitude and direction are correlated with near-degenerate NV electronic spin and hyperfine transitions from different NV orientations within the diamond host. Reasonable agreement is found between low-field AO-PL measurements and model-based simulations of the effects of resonant dipolar interactions between NV centers. Maximum observed AO-PL contrast depends on both NV concentration and laser illumination intensity at 532 nm. These results imply different optimal conditions for low-field AO NV sensing compared to conventional optically detected magnetic resonance (ODMR) techniques, suggesting new research and application opportunities using AO measurements with lower system complexity, size, weight, and power.

quant-ph↗

arXiv2024

A Kac-Weyl Character Identity

An explicit quantization of Chern-Simons theory leads to an identity between sums of the Kac-Weyl characters. One can use this identity to prove inequalities that constrain the fusion coefficients $N_{μν}^l$ in the case of RCFTs that descend from current algebras. It also leads to a statement regarding the conjugacy symmetry of the sums of squares of fusion coefficients for current algebras admitting complex representations.

math-ph↗

arXiv2024

Neon tetra fish (Paracheirodon innesi) as farm-to-optical-table Bragg reflectors

Iridophore networks in the skin of neon tetra fish are investigated for use as biologically sourced, tunable, Bragg reflector arrays. This paper reports on a method for immediate and fast post-processing of tissue to modify the structural color of iridophores found in the lateral color stripe. Conditions for fixation as well as the environment post-fixation to improve longevity of the structural color are also presented. Recent results from attempts to further increase the lifetime of post-mortem iridophore color through infiltration and embedding in low-acid glycol methacrylate are also discussed.

physics.optics↗

arXiv2024

Chirp asymmetry in Zeeman electromagnetically induced transparency

The simplest three-level system exhibiting electromagnetically induced transparency (EIT) exhibits an effective conjugation symmetry as well as a permutation symmetry. Breaking conjugation symmetry leads to a distinct chirp asymmetry; the differential response to a frequency increase versus a frequency decrease. Hanle-Zeeman EIT resonance is an ideal platform for testing the theory of chirp asymmetry because so many optical parameters of the system can be changed experimentally. We describe the theory and compare it to an experiment using 87Rb in a buffer gas cell. In contrast with earlier multi-photon chirp asymmetry work this present effort explores the asymmetry at nearly one billionth the earlier chirp rate, yet displays its universal features. Chirp asymmetry may have metrological consequences for understanding systematic dependence on modulation/demodulation parameters.

physics.atom-ph↗

arXiv2023

Newton's Off-Center Circular Orbits and the Magnetic Monopole

Introducing a radially dependent magnetic field into Newton's off-center circular orbits potential so as to preserve the $E=0$ dynamical symmetry leads to a unique choice of field that can be identified as the inclusion of a magnetic monopole in the inverse stereographically projected problem. One finds also a phenomenological correspondence with that of the linearly damped Kepler model. The presence of the monopole field deforms the symmetry algebra by a central extension, and the quantum mechanical version of this algebra reveals a number of zero modes equal to that counted using the index theorem of elliptic operators.

math-ph↗

arXiv2022

Chirp asymmetry as an analogue of Leptogenesis

The effective conjugation symmetry that arises in the rotating wave frame is the analogue of the discrete symmetry in field theory. Breaking this effective conjugation symmetry leads to asymmetries between up- and down- chirped excitation in quantum optical systems. We use semiclassical quantum optics theory to describe these processes and experimentally characterize the asymmetry in the optical response in chirped, two-color saturated absorption spectroscopy (SAS) in an atomic vapor cell. Doing so demonstrates a theoretical and phenomenological correspondence to the simplest model of leptogenesis, the process by which our universe purportedly went from equal amounts of matter and antimater to its present matter excess. The understanding of the asymmetry as due to a broken discrete symmetry under chirp appears to illuminate the underlying processes responsible for other chirp asymmetries previously noted in the literature.

physics.atom-ph↗

arXiv2021

Mechanisms of the Intensity Dependent Refractive Index in Ultrastrongly Coupled Organic Cavity Polaritons

The nonlinear optical response of organic polaritonic matter has received increasing attention due to their enhanced and controllable nonlinear response and their potential for novel optical devices such as compact photon sources and optical and quantum information devices. Using z-scans at different wavelengths and incident powers we have studied the nonlinear optical dispersion of ultrastrongly coupled organic cavity polaritons near the lower polariton band. We show that the up to 150-fold enhancement of the nonlinear response compared to a cavity-less organic film arises from an intensity-dependent polaritonic resonant frequency shift ("blueshift"). Consequently, we find that these z-scan data can only be described by several terms of a power series expansion in intensity whose respective contributions depend on power broadening and detuning from the lower polariton band. We further show that the nonlinear response can be quantitatively described by a three-level molecular quantum model coupled to the cavity in which saturation reduces the Rabi splitting, thus accounting for the lower polariton band's observed blueshift.

physics.optics↗

arXiv2020

Lagrange point stability for a rotating host mass binary

In this new era of gravitational wave astrophysics, observations have indicated the likely existence of black holes with significant spin. In order to better understand the potential imprint orbital dynamics have on the multi-messenger data, we include rotation of the primary mass to leading order in the analysis of the stability boundary pertaining to the triangular equilibrium points, L_4 and L_5, in the relativistic, restricted, circular three body problem. For Lagrange point stability these rotation effects are of the same order as the leading order relativistic corrections ignoring rotation and make both L_4 and L_5 more stable for retrograde orbital motion.

gr-qc↗

arXiv2020

Rubidium Isotope Shift Measurement using Noisy Lasers

Data students collect from the typical advanced undergraduate laboratory on Saturated Absorption Spectroscopy (SAS) of rubidium can be used to measure the isotope shift and thus leads to an estimate of the isotopic ground state energy shift. This helps students refine their `picture' of the atomic ground state. We describe theoretically why this laboratory works well with free-running laser diodes, demonstrate it experimentally using these lasers tuned to either principal near-infrared transitions, and show an extension of the laboratory using the modulation transfer spectroscopy method.

physics.atom-ph↗

arXiv2018

Dispersion of third-harmonic generation in ultrastrongly coupled organic cavity polaritons

Organic cavity polaritons are bosonic quasi-particles that arise from the strong interaction between organic molecular excitons and photons within microcavities. The spectral dispersion of third harmonic generation near resonance with the cavity polariton states is studied experimentally via angle-resolved reflected third harmonic generation measurements with several pump wavelengths. In addition, a three-step nonlinear optical transfer matrix model is used to simulate the third harmonic generation using the sum-over-states dispersive nonlinear coefficients, which include hybrid exciton-photon polariton states. The angle-dependent experiment and modeling agree, revealing that the output of third harmonic generation is resonantly enhanced when the third harmonic wavelength is near the upper polariton state. The degree of enhancement is higher on the exciton-like branch of the polariton dispersion. Lower polariton enhanced third harmonic generation is not experimentally observed due to inadequate coupling at the longer wavelength, which is also consistent with the nonlinear transfer matrix modeling. These results indicate that the sum-over-states nonlinear dispersion is descriptive of the process implying that the polariton states are terms in a complete set of states forming the basis for the perturbative calculation of the nonlinear optical response. The results also indicate the possibility of wavelength agile nonlinear optical response by angle-of-incidence tuning.

physics.optics↗

arXiv2018

Electromagnetically Induced Transparency (EIT) Amplitude Noise Spectroscopy

Intensity noise cross-correlation of the polarization eigenstates of light emerging from an atomic vapor cell in the Hanle configuration allows one to perform high resolution spectroscopy with free- running semiconductor lasers. Such an approach has shown promise as an inexpensive, simpler approach to magnetometry and timekeeping, and as a probe of dynamics of atomic coherence in warm vapor cells. We report that varying the post-cell polarization state basis yields intensity noise spectra which more completely probe the prepared atomic state. We advance and test the hypothesis that the observed intensity noise can be explained in terms of an underlying stochastic process in lightfield amplitudes themselves. Understanding this stochastic process in the light field amplitudes themselves provides a new test of the simple atomic quantum optics model of EIT noise.

physics.atom-ph↗

arXiv2016

EIT intensity correlation power broadening in a buffer gas

EIT noise correlation spectroscopy holds promise as a simple, robust method for performing high resolution spectroscopy used in optical magnetometry and clocks. Of relevance to these applications, we report here on the role of buffer gas pressure and magnetic field gradients on power broadening of Zeeman EIT noise correlation resonances.

physics.atom-ph↗

arXiv2014

Structure and Symmetry in Coherent Perfect Polarization Rotation

Theoretical investigations of different routes to coherent perfect polarization rotation illustrate its phenomenological connection with coherent perfect absorption. Studying systems with broken parity, layering, combined Faraday rotation and optical activity, or a rotator-loaded optical cavity highlights their similarity and suggests new approaches to improving and miniaturizing optical devices.

physics.optics↗

arXiv2014

Chromatic control in coextruded layered polymer microlenses

We describe the formation, characterization and theoretical understanding of microlenses comprised of alternating polystyrene and polymethylmethacrylate layers produced by multilayer coextrusion. These lenses are fabricated by photolithography, using a grayscale mask followed by plasma etching, so that the refractive index alternation of the bilayer stack appears across the radius of the microlens. The alternating quarter-wave thick layers form a one-dimensional photonic crystal whose dispersion augments the material dispersion, allowing one to sculpt the chromatic dispersion of the lens by adjusting the layered structure. Using Huygen's principle, we model our experimental measurements of the focal length of these lenses across the reflection band of the multilayer polymer film from which the microlens is fashioned. For a 56 micron diameter multilayered lens of focal length 300 microns, we measured a nearly 25 percent variation in the focal length across a shallow, 50 nm-wide reflection band.

physics.optics↗

arXiv2013

Modeling off-resonant nonlinear-optical cascading in mesoscopic thin films and guest-host molecular systems

A model for off-resonant microscopic cascading of (hyper)polarizabilities is developed using a self-consistent field approach to study mesoscopic systems of nonlinear polarizable atoms and molecules. We find enhancements in the higher-order susceptibilities resulting from geometrical and boundary orientation effects. We include an example of the dependence on excitation beam cross sectional structure and a simplified derivation of the microscopic cascading of the nonlinear optical response in guest-host systems.

physics.optics↗

arXiv2012

Coherent Perfect Rotation

Two classes of conservative, linear, optical rotary effects (optical activity and Faraday rotation) are distinguished by their behavior under time reversal. In analogy with coherent perfect absorption, where counterpropagating light fields are controllably converted into other degrees of freedom, we show that only time-odd (Faraday) rotation is capable of coherent perfect rotation in a linear and conservative medium, by which we mean the complete transfer of counterpropagating coherent light fields into their orthogonal polarization. This highlights the necessity of time reversal odd processes (not just absorption) and coherence in perfect mode conversion and may inform device design.

physics.optics↗

arXiv2005

Classification of N=2 Superconformal Field Theories with Two-Dimensional Coulomb Branches

We study the classification of 2-dimensional scale-invariant rigid special Kahler (RSK) geometries, which potentially describe the Coulomb branches of N=2 supersymmetric field theories in four dimensions. We show that this classification is equivalent to the solution of a set of polynomial equations by using an integrability condition for the central charge, scale invariance, constraints coming from demanding single-valuedness of physical quantities on the Coulomb branch, and properties of massless BPS states at singularities. We find solutions corresponding to lagrangian scale invariant theories--including the scale invariant G_2 theory not found before in the literature--as well as many new isolated solutions (having no marginal deformations). All our scale-invariant RSK geometries are consistent with an interpretation as effective theories of N=2 superconformal field theories, and, where we can check, turn out to exist as quantum field theories.

hep-th↗

arXiv2002

Measuring the Earth with Traceroute

The traceroute utility on any computer connected to the Internet can be used to record the roundtrip time for small Internet packets between major Internet traffic hubs. Some of the routes include transmission over transoceanic fiber optic cable. We report on traceroute's use by students to quickly and easily estimate the size of the Earth. This is an inexpensive way to involve introductory physics students in a hands-on use of scientific notation and to teach them about systematics in data.

physics.ed-ph↗