Optical Spectral Singularities and Coherent Perfect Absorption in a Two-Layer Spherical Medium

An optical spectral singularity is a zero-width resonance that corresponds to lasing at threshold gain. Its time-reversal causes coherent perfect absorption of light and forms the theoretical basis of antilasing. In this article we explore optical spectral singularities of a two-layer spherical medium. In particular, we examine the cases that a gain medium is coated by a thin layer of high-refractive index glass and a spherical glass covered by a layer of gain material. In the former case, the coating reduces the minimum radius required for exciting spectral singularities and gives rise to the formation of clusters of spectral singularities separated by wide spectral gaps. In the latter case, the coating leads to a doubling of the number of spectral singularities.Comment: 19 pages, 1 table, 10 figures, accepted for publication in Proc. R. Soc.

Manipulating Synchronous Optical Signals with a Double Λ\Lambda Atomic Ensemble

We analyze a double $\Lambda$ atomic configuration interacting with two signal beams and two control beams. Because of the quantum interference between the two $\Lambda$ channels, the four fields are phase-matched in electromagnetically induced transparency. Our numerical simulation shows that this system is able to manipulate synchronous optical signals, such as generation of optical twin signals, data correction, signal transfer and amplification in the atomic storage.Comment: 5 pages, 7 figure

Do Lower Extremity Injuries of NFL Players Affect their Yearly Income?

Introduction: Injuries are arguably the most daunting career setbacks professional sports players have to face. To better understand the drawbacks of sports injuries, we decided to examine players’ annual income before and after sports injuries. Income is arguably the most important metric of success for professional athletes. To make the study more relevant for the US, we collected data on one of the most viewed professional sports leagues in the country: the National Football League (NFL). Methods: We examined the NFL’s weekly injury reports for seasons from 2016 to 2020, and recorded players with lower extremity injuries (LEI) (Hamstring, Calves, Groin, or Quadricep). We accessed pro-football-reference.com and spotrac.com to record player identifiers and individual annual salaries 3 years prior to the index injury and up to 7 years after if data was available respectively. A google spreadsheet was used to record all information noted above. Results: Data is available, pending analysis. Discussion: This project will allow us to better understand the impact injuries have on the lives of hundreds of professional sports players and how it can alter the course of their careers. This project sheds light on the importance of this topic. We plan to build off of this in future research by examining variables that affect recovery time and the recurrence of injury throughout athletes’ careers

Light propagation in atomic Mott Insulators

We study radiation-matter interaction in a system of ultracold atoms trapped in an optical lattice in a Mott insulator phase. We develop a fully general quantum model, and we perform calculations for a one-dimensional geometry at normal incidence. Both two- and three-level $\Lambda$ atomic configurations are studied. The polariton dispersion and the reflectivity spectra are characterized in the different regimes, for both semi-infinite and finite-size geometries. We apply this model to propose a photon energy lifter experiment: a device which is able to shift the carrier frequency of a slowly travelling wavepacket without affecting the pulse shape nor its coherence

Is old really gold? Examining the effect of playing experience in preventing professional athletes’ injuries

Introduction: The literature contains research showing that age increases the risk of injury in individuals who live sedentary lives. Looking at injury rates in individuals who are active for a living can better inform the importance of exercise training regimens in an aging population Methods: Combing player injury data from thet NFL and player statistics from pro-football-reference.com, we will create a dataset containing variables like seasons played in the NFL and age of player at time of injury. We will include all uninjured players in our dataset for comparison. We will use ANOVA to figure out how much these variables accounted for the incidence of injury in athletes. Results: Data is in the process of being collected. We expect that data analysis will likely indicate that player position (Quarter back, Linebacker, etc.) was the variable recorded that explained the most variance in injury. Age of player might be weakly positively correlated and seasons played in the NFL will probably have no correlation. Discussion: Seasons played probably does not correlate to injury risk since many NFL players have played football for multiple years prior to the NFL: future NFL players may start their football careers in middle school or highschool and spend differing amounts of time in college football, it is unfeasible to use this variable to extrapolate the actual amount of football experience players have. While older players are likely more injury prone than younger players, this factor is minimal compared to the likely effect of player position. Probably, active older adults should be encouraged to pursue physical activity that has been shown to have less risk of injury

Do Lower Extremity Injuries of NFL Players Affect their Contracts?

Introduction: There is likely a correlation between National Football League (NFL) players who endure lower extremity injuries (LEI) and the length and remuneration of subsequent contracts. This kind of data can be useful in training a model to predict how an injury may influence a player’s contracts in the future. Methods: We examined the NFL’s weekly injury reports for seasons from 2016 to 2020, and recorded players with lower extremity injuries (LEI) (Hamstring, Calves, Groin, or Quadricep). We accessed pro-football-reference.com and spotrac.com to record player identifiers and individual annual salaries 3 years prior to the index injury and up to 7 years after if data was available respectively. A google spreadsheet was used to record all information noted above.We will use machine learning to create a model of these variables. Results: Our analysis likely indicates that LEI has a strong negative correlation with reduction in length of a player’s subsequent contract and reduction in annual salary. Our working hypothesis is that mean contract length will be reduced by six months and mean annual salary will be reduced by $50,000. Discussion: This project will allow our team to further explore the implications of injuries on the careers of athletes and what other barriers these injuries create for players participating in these sports. This project can act as a stepping stone to help elucidate how a variety of lower extremity orthopedic injuries may impact professional athletes’ career measured by their earning potential

Optical properties of atomic Mott insulators: from slow light to dynamical Casimir effects

We theoretically study the optical properties of a gas of ultracold, coherently dressed three-level atoms in a Mott insulator phase of an optical lattice. The vacuum state, the band dispersion and the absorption spectrum of the polariton field can be controlled in real time by varying the amplitude and the frequency of the dressing beam. In the weak dressing regime, the system shows unique ultra-slow light propagation properties without absorption. In the presence of a fast time modulation of the dressing amplitude, we predict a significant emission of photon pairs by parametric amplification of the polaritonic zero-point fluctuations. Quantitative considerations on the experimental observability of such a dynamical Casimir effect are presented for the most promising atomic species and level schemes

Which position in American Football is more likely to get you benched due to LEI? An Analysis of NFL Players injured in the years 2016-2020.

Title: Which position in American Football is more likely to get you benched due to LEI? An Analysis of NFL Players injured in the years 2016-2020. Authors: Robert de la Torre, Abdullah Sahyouni, Kinan Sawar, Gautham Pavar, Cris J. Diaz Alvarenga, Shravan Morisetty, Justin Bennie, Bohdan Matsko, Niyaz Uddin, Olivia Pakula Introduction: In American Football, there are twenty-four different positional roles that a player may assume. Some positions are unique to offense, such as quarterback and wide receiver. Others are unique to defense, such as cornerback or linebacker. There are also unique positions such as kicker or punter. All of these positions have different roles on the field and thus, different kinesiological patterns. These differences may lead to a variation in LE injuries experienced by players in different positions. Due to the prevalence of LEI\u27s in the NFL, we wanted to look at the trends for different injuries to see if there is positional correlation. Methods: We examined the NFL’s weekly injury reports for seasons from 2016 to 2020, and recorded players with four different categories of lower extremity injuries (LEI): (Hamstring, Calves, Groin, or Quadricep). Both the positional data and the nature of the injury are presented on NFL.com. We are looking at the frequency of various injuries in relation to position, as well as injury timelines for the four different LE injury categories. Results: Data is available and pending analysis. Discussion: The data collected from this study may be beneficial for any athlete engaging in organized football. Individuals with a certain injury history can be made aware of the impact their specific roles on the field may have on their injury. This can be useful information for parents and coaching staff/trainers to be aware of. Injuries to key players can dramatically impede a football season\u27s success in both monetary and subjective terms

Enhanced Evanescent Field Spectroscopy at Waveguide Surfaces using High Index Nano and Near-Nano Layers

We propose and demonstrate, through simulation and experiment, how the interaction of an optical field within a waveguide designed for chemical sensing and, more generally, evanescent field spectroscopy can be enhanced substantially by strategic deposition of high index surface layers. These layers draw out the optical field in the vicinity of probing and take advantage of field localisation through optical impedance matching. Localisation of the evanescent field to the inner layer in turn is accompanied by whispering gallery modes within the channels of a structured cylindrical waveguide, further enhancing sensitivity. A novel demonstration based on self-assembled layers made up of TiO2 within a structured optical fibre is demonstrated, using a simple porphyrin as the spectroscopic probe. This technique offers optimisation of the limitations imposed on practical waveguide sensors that are highly sensitive but nearly always at the expense of low loss. The principles have potential ramifications for nanophotonics more generally and these are discussed

Coherent coupling between radio frequency, optical, and acoustic waves in piezo-optomechanical circuits

The interaction of optical and mechanical modes in nanoscale optomechanical systems has been widely studied for applications ranging from sensing to quantum information science. Here, we develop a platform for cavity optomechanical circuits in which localized and interacting 1550 nm photons and 2.4 GHz phonons are combined with photonic and phononic waveguides. Working in GaAs facilitates manipulation of the localized mechanical mode either with a radio frequency field through the piezo-electric effect, or optically through the strong photoelastic effect. We use this to demonstrate a novel acoustic wave interference effect, analogous to coherent population trapping in atomic systems, in which the coherent mechanical motion induced by the electrical drive can be completely cancelled out by the optically-driven motion. The ability to manipulate cavity optomechanical systems with equal facility through either photonic or phononic channels enables new device and system architectures for signal transduction between the optical, electrical, and mechanical domains