26 research outputs found
Optically isotropic longitudinal piezoelectric resonant photoelastic modulator for wide angle polarization modulation at megahertz frequencies
Polarization modulators have a broad range of applications in optics. The
acceptance angle of a free-space polarization modulator is crucial for many
applications. Polarization modulators that can achieve a wide acceptance angle
are constructed by attaching a piezoelectric transducer to an isotropic
material, and utilize a resonant transverse interaction between light and
acoustic waves. Since their demonstration in the 1960s, the design of these
modulators has essentially remained the same with minor improvements in the
following decades. In this work, we show that a suitable single crystal with
the correct crystal orientation, functioning as both the piezoelectric
transducer and the acousto-optic interaction medium, could be used for
constructing a highly efficient free-space resonant polarization modulator
operating at megahertz frequencies and exhibiting a wide acceptance angle. We
construct the modulator using gallium arsenide, an optically isotropic and
piezoelectric crystal, and demonstrate polarization modulation at 6 MHz with an
input aperture of 1 cm in diameter, acceptance angle reaching ,
and modulation efficiency exceeding 50%. Compared to state-of-the-art resonant
photoelastic modulators, the modulator reported in this work exhibits greater
than 50 fold improvement in modulation frequency for the same input aperture,
while simultaneously reducing the thickness by approximately a factor of 80.
Increasing the modulation frequency of photoelastic modulators from the
kilohertz to the megahertz regime and substantially reducing their thickness
lead to significant performance improvements for various use cases. This
technological advancement also creates opportunities for utilizing these
devices in new applications.Comment: 19 pages, 10 figure
Sense, Predict, Adapt, Repeat: A Blueprint for Design of New Adaptive AI-Centric Sensing Systems
As Moore's Law loses momentum, improving size, performance, and efficiency of
processors has become increasingly challenging, ending the era of predictable
improvements in hardware performance. Meanwhile, the widespread incorporation
of high-definition sensors in consumer devices and autonomous technologies has
fueled a significant upsurge in sensory data. Current global trends reveal that
the volume of generated data already exceeds human consumption capacity, making
AI algorithms the primary consumers of data worldwide. To address this, a novel
approach to designing AI-centric sensing systems is needed that can bridge the
gap between the increasing capabilities of high-definition sensors and the
limitations of AI processors. This paper provides an overview of efficient
sensing and perception methods in both AI and sensing domains, emphasizing the
necessity of co-designing AI algorithms and sensing systems for dynamic
perception. The proposed approach involves a framework for designing and
analyzing dynamic AI-in-the-loop sensing systems, suggesting a fundamentally
new method for designing adaptive sensing systems through inference-time
AI-to-sensor feedback and end-to-end efficiency and performance optimization
Polarization-insensitive wide-angle resonant acousto-optic phase modulator
Phase modulators are commonly used devices in optics. Free-space phase
modulators are typically constructed from optically anisotropic crystals
exhibiting the Pockels effect. To preserve the light's polarization state as it
propagates through the crystal, it is essential to align the polarization and
angle of incidence of the light with respect to the crystal. In this study, we
demonstrate the feasibility of constructing free-space resonant phase
modulators with a broad acceptance angle and minimal dependence on the
polarization state of light using an acousto-optic approach. These modulators
operate in the megahertz frequency range, require modest power levels, have
aperture sizes exceeding one square centimeter, and feature sub-millimeter
thickness.Comment: 8 pages, 6 figure
Adaptive Inference: Theoretical Limits and Unexplored Opportunities
This paper introduces the first theoretical framework for quantifying the
efficiency and performance gain opportunity size of adaptive inference
algorithms. We provide new approximate and exact bounds for the achievable
efficiency and performance gains, supported by empirical evidence demonstrating
the potential for 10-100x efficiency improvements in both Computer Vision and
Natural Language Processing tasks without incurring any performance penalties.
Additionally, we offer insights on improving achievable efficiency gains
through the optimal selection and design of adaptive inference state spaces