Bixler, Joel - 210-539-8172

Accurately simulating laser damage caused by high energy laser exposure requires the complete knowledge of how tissue optical properties (absorption and reduced scattering coefficients) change as a function of tissue heating and damage. Measuring such properties is a difficult endeavor as no methods currently exist for directly measuring these properties. Indirect methods, such as using integrating spheres in conjunction with inverse adding doubling based solvers can provide estimates on such properties and can be used to study dynamics in excised tissues. This project is focused on measuring tissue dynamics using integrating sphere-based sensing, combined with validating novel methods under development to measure optical properties. Additional research will focus validating modeling tools used to predict tissue damage and expanding these tools to incorporate the physics of laser ablation.

Lovell, Julie - 210-539-8550

This is a multifaceted program integrating vision science, experimental psychophysics, and augmented/virtual reality (AR/VR). A topic of particular interest is studying bright laser or broadband light exposure and color vision effects incorporating complex scenes within an augmented/virtual reality simulator. Laboratory psychophysical experiments are conducted to develop and validate the scenarios integrated into the simulator. Adaptation effects along with advantages/limitations of VR are of interest as well. Other related areas of research include spatial vision, intraocular scatter, disability glare, discomfort glare, flashblindness, photostress recovery, macular pigment, color constancy, vision at mesopic levels, color zones and color naming, attention, and eye movements. Candidates with demonstrated laboratory experience in vision science and augmented/virtual reality simulators are desired. Selected applicants should expect to work with USAF staff, collaborating university faculty, and contract support staff to develop models and conduct experiments to validate models.

Wharmby, Andrew - 210-539-8284

Research has shown that biophysical processes, such as laser-tissue interaction, deviate from the predictions given by traditional mathematical models for short laser exposure times. In general, it was found that the shorter the exposure time is, the stronger the deviation will be. However, generalizing these models by recasting them as fractional order differential equations have resulted in models that show high agreement with experimental observation regardless of exposure duration. This effort aims to analyze these new equations that employ elements of the fractional calculus (and other non-local operators) and apply them to other biophysical phenomena such as thermal diffusion resulting from laser heating and fluorescence from UV lasers. The development of these novel mathematical models will quantify and enhance safety standards for newly developed protective materials and directed energy devices. Candidates with demonstrated knowledge of the fractional calculus and its implications in both analytical and numerical models are desired. Selected applicants should expect to work with USAF staff, collaborating university faculty and students, and contract support staff to develop models.

Goettl, Barry - 210-539-7885

Development of new technologies to protect against flash blindness and retinal damage from lasers and other optical hazards requires an understanding of how material solutions for protecting the eyes interact with vision and human performance. These filters must block enough light to protect the eyes yet pass enough for aircrew members to perform their mission. This is particularly challenging at night when there is less ambient light, flash blindness is easier to induce, and operations may require disciplined display illumination levels to protect operations. Over the years, the US Air Force has developed a number of Laser Eye Protection (LEP) devices and conducted many laboratory, ground, and flight tests to certify LEP safe for use in cockpits. Although many LEP have been fielded, aircrew often report problems with color and visibility resulting in low acceptance and use of LEP, even when the risk of laser exposure is high. Experimentation is needed to develop models of how visual glare and protective filters effect vision, cognition, attention and human performance. Desired candidates have demonstrated laboratory experience in vision science, cognition, attention, human factors and/or human performance modeling. Selected applicants should expect to work with USAF staff, collaborating university faculty, and summer students at the graduate and undergraduate level. Summer projects will develop and integrate models of vision, cognition, attention or human performance for predicting the effects of filters on visual dazzle and human performance.

Ashworth, Alan - 210-536-1963

Researchers will assist in the development of models to describe the relationship between the physical effect of non-lethal weapons and the behavioral response. Modeling efforts range from process models describing qualitative relations between factors, to computational models for generating quantitative predictions based upon real time data collection. To be considered are: 1) individual psychological factors such as motivation, experience with and knowledge of the weapon, tolerance for pain and discomfort, observation of weapon use on a third party, gender, and age; 2) social factors such as cultural background, religion, group size, conformity, impressions of authority; 3) environmental factors such as ambient levels of temperature, light, and sound; and 4) type of non-lethal weapon such as blunt impact, riot control agents, malodorants, directed energy, flashbang, blast overpressure, and electromuscular stimulation. Candidates with demonstrated experience in the field or applicable associated research are desired. Selected applicants should expect to work with USAF staff, collaborating university faculty, and contract support staff to develop models and draft guidance to inform policy decisions and security classification guides.

Denton, Michael - 210-539-8069

The goal of this research is to determine the effect of laser exposure on human tissues and to study the resulting mission impact. The analysis includes quantification of tissue parameters, response of tissues to optical irradiation, and modeling of the interaction. We study photoacoustic, photothermal, cellular insult, photochemical, and photomechanical processes and their effect on tissues. Understanding laser tissue interaction is the first step toward optimizing military application of laser radiation. Our work emphasizes the occupational and environmental health aspects of laser tissue interaction, with experiments coupled with modeling efforts, which result in suggestions to the laser safety community where safety standards either do not exist, or where deficiencies in biological data has made the criteria for setting standards ambiguous. In addition, we seek to understand and monitor changes in tissue optical properties and function as a result of laser exposure. The laboratory offers extensive laser facilities and support equipment (including retinal and skin imaging) to investigate effects across the pulse-duration and wavelength spectrum.