LOCI RESEARCH

The goal of LOCI is to develop an Air Force Center of Excellence in LADAR and laser communications research and education. LOCI is cooperating with AFRL to develop and implement research programs and integrate students and faculty into the research and technology development. LOCI is developing a relevant LADAR curriculum in cooperation with AFIT, constructed and currently maintaining supporting state of the art laboratories on campus, and develop and cultivate industrial and academic partnerships.

	Active multi-spectral foliage penetration Goal: * Oblique angle of incidence penetration and scattering of light from a canopy. * Extensive Monte Carlo calculations to understand the phenomenology. * Experiments on local canopy gap fractions. * Analysis of data and comparison with MC calculations.
	Multi-frequency chirped laser pulses for improved range resolution This research is examining the theoretical and experimental aspects of multiple laser line linear frequency chirped signal processing for improving range resolution. Calculations established that a factor of two improvement in range resolution could be achievable with two chirped frequencies. Additional improvement is found for a third and fourth frequency, as well. Goal: * Complete calculations for chirped multi-frequency laser pulses and heterodyne detection and processing of field amplitudes. Use the results to specify experimental components. * Design and conduct experiments with two detuned lasers.
	Aperture synthesis technologies Coherent imaging research experiment using multiple apertures. Goal: * Using phase shift technique, compute image plane phase field. Study statistical properties of computed phase field and investigate phase unwrapping techniques. Synthesize image from sub-aperture pupil plane fields measured by Phase Stepping Interferometry technique. Methods are developed to mitigate image speckle. * Examination of alternate sparse aperture phase retrieval methods.
	Non-mechanical beamsteering for LADAR applications A large aperture (20 mm) Faraday rotator device is being used as an R/T switch for a LADAR module. This obviates the need for a quarter-wave plate and enables linear polarization to be transmitted. The project will experimentally verify new concept of focal plane shifter beam steering. Different beam steerers will be examined including: Liquid crystal (LC) based beam steering devices and Electro-optic (EO) beam steering devices. Goal: * Gaussian beam characterization using a camera and parabolic mirrors for off-axis beams. Katharine will gain working experience with Gaussian beam optics April-June 2008. * Understanding the polarization issues in the LC beamsteering by theoretical modeling. Integration of a beam steering subsystem (LC SLM or Risley prisms) to study component interactions with Faraday rotator and evaluated overall performance for T/R setup. * Design and test beam steering with LC devices.
	Single holographic aperture demonstration A synthetic aperture reconstruction of a moving transmitter/receiver system to improve the resolution. Goal: * Calculations of effects of platform vibrations and laser pulse timing jitter. Experimental design and construction based on simulations.
	Non-uniform sparse aperture and sub-aperture pupil apodization A multiple aperture project designed to improve image contrast. Goal: * A theoretical examination of sub apertures with different radii and different opacity, starting with Golay topologies. * Simulations to drive the MTF to higher frequencies with improved image contrast.
	Laser beam propagation and interaction with simulated targets Research on the experiments and design concepts for simulating the speckle field associated with laser propagation through the atmosphere and scattered from a scattering target. Goal: * Experiments and design concepts for simulating the speckle field associated with laser propagation through the atmosphere and scattered from a scattering target. * Theoretical simulations on partially coherent light fields to anchor the experimental results and modeling approach.
	Testbed design and implementation LOCI researchers in cooperation with AFRL researchers are designing and building a multi-aperture testbed with visible and NIR capabilities to examine the optical components and post-processing approaches to multi-aperture imaging.