This award supports theoretical research and education to advance the theoretical description and design of novel laser systems with complex media and multiple scattering playing a central role.
Many novel modern laser systems involve complex resonator geometries such micro-cavities, photonic crystals and even random lasers based on disordered scattering media with gain. These lasers have a wide range of potential applications and are challenging to simulate and understand using conventional methods. The PI has developed a method, known as steady-state ab initio laser theory, that provides a tractable way to simulate and design as well as new physical insights into their behavior. The method agrees with full time-dependent numerical solutions of the laser equations with much less computational effort.
The PI will generalize his steady-state ab initio laser theory with an aim to develop a unified framework for describing many different laser systems. The PI will extend the theory to describe multi-transition lasers and semiconductor gain media, including the effects of gain diffusion, and injection-locking of lasers. New types of lasing modes are found when certain lasers are non-uniformly pumped in space; this behavior is related to the appearance of exceptional points in the relevant wave equations, where two solutions merge. These phenomena will be extensively studied to elucidate their implications. A first principles theory of quantum effects in lasers will be obtained by combining the steady-state ab initio laser theory, which provides the classical scattering matrix of the laser, with input-output theory, which describes the scattered quantum operators. Quantum fluctuations determine the laser linewidth and photon statistics, which can be predicted with no free or phenomenological parameters with the PI's approach.
The PI intends the extended theory to become a computational tool for the design of applied laser systems for technological purposes such as communications, quantum information processing, spectrometry, projectors, optical coherence tomography and imaging. The extension of the approach to semiconductor gain media will lead to improvements in the modeling of quantum cascade and conventional semiconductor lasers. An open source computational tool for laser design using the approach pioneered by the PI is being developed and will be made available to researchers in academia and industry in the course of this project.
NONTECHNICAL SUMMARY
This award supports theoretical research and education focused on improving the capability to understand and design novel laser systems, which are fundamental tools in research across the sciences, and a basic technology underlying the modern economy. Lasers are non-linear systems and also involve complex patterns of wave propagation within and outside the laser, hence the theory of these devices is quite challenging. New materials and materials systems play an important role in shaping potential laser technologies. This award supports the development of theory and related computational algorithms to enhance to enable quantitative solutions to the equations describing novel laser systems under current development, hence allowing better and more efficient designs for these systems. Important potential applications for the research are in the areas of communications, quantum information processing, spectrometry, biological sensing, projectors, optical coherence tomography and imaging. A spin-off from the theory is the concept of the "anti-laser," a novel device for selectively absorbing light with only very specific properties. An open source computational tool for laser design using the approach pioneered by the PI is being developed and will be made available to researchers in academia and industry in the course of this project.
