Examination of a Lensless Setup for Reflective Inverse Diffusion of Light
Abstract
Reflective inverse diffusion uses spatial light modulators to shape an incident wavefront so that when the wavefront interacts with some diffuse scattering sample, the reflected light will constructively interfere at a single focus. By combining reflective inverse diffusion with beam steering, it is possible to image objects around corners and obstacles. Traditionally, reflective inverse diffusion uses a focal plane system where a lens would focus light modified by the spatial light modulator onto the scattering sample. The focal plane system would also have to compensate for the Fourier transform when beamsteering with the lens. Removal of this lens from the system allows any modulation of the incident light to be directly projected onto a scattering sample. Additionally, limitations in the system from the 2D Fourier transform of the lens would be lifted in a lensless system and allow for more light to be focused at a single spot. This thesis examines the efficacy of the lensless system against the focal plane system in achieving reflective inverse diffusion and beamsteering. Although the lensless setup outperformed its counterpart by being able to focus more energy in a region, the lensless setup failed to achieve the same beam steering capabilities as the focal plane system. Understanding the flaws behind the lensless system will be instrumental in creating a setup that will achieve reflective inverse diffusion while possessing the capability to effectively beamsteer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2021
- Accession Number
- AD1145715
Entities
People
- John Nguyen
Organizations
- Air Force Institute of Technology