Methods for Focal Plane Array Resolution Estimation Using Random Laser Speckle in Nonparaxial Geometries
Abstract
The infrared (IR) community has a need for detector evaluation due to the continued demand for small pixel pitch detectors, the emergence of strained-layer-superlattice devices, and the associated lateral carrier diffusion issues. Conventional laser speckle-based modulation transfer function (MTF) estimation is dependent on Fresnel propagation, limiting utilization on lambda-scale IR devices. This effort develops two methodologies for resolution evaluation of IR focal plane arrays (FPA). Both techniques are valid in nonparaxial geometries dictated by lambda-scale devices. The generalized FPA MTF estimation approach numerically evaluates Rayleigh-Sommerfeld speckle autocorrelation functions to indirectly compute the power spectral density (PSD) of a non-wide-sense-stationary (WSS) speckle random process. This method is demonstrated on a lambda-scale longwave infrared FPA, showing at 27 percent spatial frequency range improvement over the established methodology. A resolution estimation approach, which utilizes employs a maximum likelihood estimation approach to solve for a system impulse response, is demonstrated with simulated imagery.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 10, 2022
- Accession Number
- AD1177689
Entities
People
- Philip J. Plummer
Organizations
- Air Force Institute of Technology