John C. Howell
YOU?
Author Swipe
View article: Demonstrating Superresolution in Radar Range Estimation Using a Denoising Autoencoder
Demonstrating Superresolution in Radar Range Estimation Using a Denoising Autoencoder Open
We apply machine learning methods to demonstrate range superresolution in remote sensing radar detection. Specifically, we implement a denoising autoencoder to estimate the distance between two equal intensity scatterers in the subwaveleng…
View article: Compressed sensing enabled high-bandwidth and large dynamic range magnetic sensing
Compressed sensing enabled high-bandwidth and large dynamic range magnetic sensing Open
Electron Spin Resonance (ESR) is a widely common method in the field of quantum sensing. Specifically with the Nitrogen-Vacancy (NV) center in diamond, used for sensing magnetic and electric fields, strain and temperature. However, ESR mea…
View article: Reconstructing superoscillations buried deeply in noise
Reconstructing superoscillations buried deeply in noise Open
We utilize a method using frequency combs to construct waves that feature superoscillations—local regions of the wave that exhibit a change in phase that the bandlimits of the wave should not otherwise allow. This method has been shown to …
View article: Raspberry Pi multispectral imaging camera system (PiMICS): a low-cost, skills-based physics educational tool
Raspberry Pi multispectral imaging camera system (PiMICS): a low-cost, skills-based physics educational tool Open
We report on an educational pilot program for low-cost physics experimentation run in Ecuador, South Africa, and the United States. The program was developed after having needs-based discussions with African educators, researchers, and lea…
View article: Reconstructing Superoscillations Buried Deeply in Noise
Reconstructing Superoscillations Buried Deeply in Noise Open
We utilize a method using frequency combs to construct waves that feature superoscillations - local regions of the wave that exhibit a change in phase that the bandlimits of the wave should not otherwise allow. This method has been shown t…
View article: Optimal radar ranging pulse to resolve two reflectors
Optimal radar ranging pulse to resolve two reflectors Open
Previous work established fundamental bounds on subwavelength resolution for the radar range resolution problem, called superradar []. In this work, we identify the optimal waveforms for distinguishing the range resolution between two refl…
View article: Reconciling and validating the Ashworth–Davies Doppler shifts of an arbitrarily translating mirror
Reconciling and validating the Ashworth–Davies Doppler shifts of an arbitrarily translating mirror Open
We simplify, to first order in v c , the generalized, special relativistic treatment of a Doppler shift from an arbitrarily translating mirror originally derived by Ashworth and Davies [ Proc. IEEE 64 , 280 ( 1976 ) IEEPAD 0018-9219 10.110…
View article: The Best Radar Ranging Pulse to Resolve Two Reflectors
The Best Radar Ranging Pulse to Resolve Two Reflectors Open
Previous work established fundamental bounds on subwavelength resolution for the radar range resolution problem, called superradar [Phys. Rev. Appl. 20, 064046 (2023)]. In this work, we identify the optimal waveforms for distinguishing the…
View article: Fundamental Limits on Subwavelength Range Resolution
Fundamental Limits on Subwavelength Range Resolution Open
We establish fundamental bounds on subwavelength resolution for the radar ranging problem, ``super radar''. Information theoretical metrics are applied to probe the resolution limits for the case of both direct electric field measurement a…
View article: Super Interferometric Range Resolution
Super Interferometric Range Resolution Open
We probe the fundamental underpinnings of range resolution in coherent remote sensing. We use a novel class of self-referential interference functions to show that we can greatly improve upon currently accepted bounds for range resolution.…
View article: Super-phenomena in arbitrary quantum observables
Super-phenomena in arbitrary quantum observables Open
Superoscillations occur when a globally band-limited function locally oscillates faster than its highest Fourier coefficient. We generalize this effect to arbitrary quantum mechanical operators as a weak value, where the preselected state …
View article: Doppler Gyroscopes: Frequency vs Phase Estimation
Doppler Gyroscopes: Frequency vs Phase Estimation Open
We consider the fundamental roles of frequency versus phase in parameter estimation, specifically in the Sagnac effect. We describe a novel, ultrasensitive gyroscope based on the extremely steep frequency-dependent gain of a liquid crystal…
View article: Reconciling and Validating the Ashworth-Davies Doppler Shifts of a Translating Mirror
Reconciling and Validating the Ashworth-Davies Doppler Shifts of a Translating Mirror Open
We simplify the Ashworth-Davies special relativistic theory of a uniformly translating mirror with an arbitrary angle of incidence and direction of propagation in the non-relativistic limit. We show that it is in good agreement with a more…
View article: Generalized Nighttime Radiative Deficits
Generalized Nighttime Radiative Deficits Open
© This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/. Deposited by shareyourpaper.org and openaccessbutton.org. We've taken reasonable steps to ensure this content…
View article: Deep Radiative Cooling Passive Dew Collection
Deep Radiative Cooling Passive Dew Collection Open
We show how to overcome almost every major limitation in passive dew collection including: parasitic heating, parasitic evaporation, uncontrolled wind conditions, and performing dew collection 24 hours per day at nearly arbitrary relative …
View article: Deep, high yield, passive dew collection
Deep, high yield, passive dew collection Open
Based on advances in deep radiative cooling (i.e., radiative cooling very far below ambient temperature), and by separating the roles of the radiative emitter and dew collector, we derive new theoretical dew collection limits. We verified …
View article: Femtometer displacement resolution with phase-insensitive Doppler sensing
Femtometer displacement resolution with phase-insensitive Doppler sensing Open
The measurement of extremely small displacements is of utmost importance for fundamental studies and practical applications. One way to estimate a small displacement is to measure the Doppler shift generated in light reflected off a moving…
View article: Compressive direct imaging of a billion-dimensional optical phase space
Compressive direct imaging of a billion-dimensional optical phase space Open
Optical phase spaces represent fields of any spatial coherence and are typically measured through phase-retrieval methods involving a computational inversion, optical interference, or a resolution-limiting lenslet array. Recently, a weak-v…
View article: Short-wave infrared compressive imaging of single photons
Short-wave infrared compressive imaging of single photons Open
We present a short-wave infrared (SWIR) single photon camera based on a single superconducting nanowire single photon detector (SNSPD) and compressive imaging. We show SWIR single photon imaging at a megapixel resolution with a low signal-…
View article: Characterizing High-Dimensional Optical Systems with Applications in Compressive Sensing and Quantum Data Locking
Characterizing High-Dimensional Optical Systems with Applications in Compressive Sensing and Quantum Data Locking Open
This University of Rochester Physics Ph.D. dissertation introduces concepts in compressive sensing, quantum entanglement, FMCW LiDAR, and quantum data locking. Additionally, the appendix serves as a thorough reference for those interested …
View article: Practical advantages of almost-balanced-weak-value metrological techniques
Practical advantages of almost-balanced-weak-value metrological techniques Open
Precision measurements of ultrasmall linear velocities of one of the mirrors in a Michelson interferometer are performed using two different weak-value techniques. We show that the technique of almost-balanced weak values (ABWV) offers pra…
View article: Slow light in flight imaging
Slow light in flight imaging Open
Slow-light media are of interest in the context of quantum computing and\nenhanced measurement of quantum effects, with particular emphasis on using\nslow-light with single photons. We use light-in-flight imaging with a single\nphoton aval…
View article: Study of Cardiovascular Outcomes in Renal Transplantation: A Prospective, Multicenter Study to Determine the Incidence of Cardiovascular Events in Renal Transplant Recipients in Ontario, Canada
Study of Cardiovascular Outcomes in Renal Transplantation: A Prospective, Multicenter Study to Determine the Incidence of Cardiovascular Events in Renal Transplant Recipients in Ontario, Canada Open
Background: Renal transplant recipients (RTRs) are at significantly higher risk for morbidity and mortality compared with the general population, largely attributed to cardiovascular disease (CVD). Previous estimates of CVD events have com…
View article: All-Fiber, Directly Chirped Laser Source for Chirped-Pulse-Amplification
All-Fiber, Directly Chirped Laser Source for Chirped-Pulse-Amplification Open
Chirped-pulse–amplification (CPA) technology is
widely used to produce ultra-short optical pulses (sub picosecond
to femtoseconds) with high pulse energy. A chirped pulse laser
source with flexible dispersion control is highly desirable as…
View article: Complementary weak-value amplification with concatenated postselections
Complementary weak-value amplification with concatenated postselections Open
We measure a transverse momentum kick in a Sagnac interferometer using weak-value amplification with two postselections. The first postselection is controlled by a polarization-dependent phase mismatch between both paths of the interferome…
View article: Quantum enigma machine: Experimentally demonstrating quantum data locking
Quantum enigma machine: Experimentally demonstrating quantum data locking Open
Shannon proved in 1949 that information-theoretic-secure encryption is possible if the encryption key is used only once, is random, and is at least as long as the message itself. Notwithstanding, when information is encoded in a quantum sy…
View article: Weak-value amplification of the fast-light effect in rubidium vapor
Weak-value amplification of the fast-light effect in rubidium vapor Open
We use weak-value amplification to enhance the polarization-sensitive\nfast-light effect from induced Raman absorption in hot rubidium vapor. We\nexperimentally demonstrate that projecting the output signal into an\nappropriate polarizatio…