RAJENDRA JOSHI. Fabrication, Characterization, and Modeling of Random Anti-reflective Optical Surface Structures. (Under the direction of DR. GREGORY J. GBUR)Optical surfaces can be fabricated to be anti-reflective (AR) by coating single- or multi-layered dielectrics on them. However, the optical response through these surfaces is polarization- dependent and angle-dependent, and they degrade quickly on exposure to the environment and laser radiation. One alternative to these coated AR surfaces are periodic sub-wavelength AR structures, which possess no material mismatch with the substrate, contrary to that in the case of dielectric-coated AR surfaces. The polarization-dependency and angle-dependency of optical response of these structured surfaces is still an issue for some applications, however.Optical surfaces fabricated with random AR surface structures (rARSS) have proven to be largely angle-independent and polarization-independent. They also withstand higher power laser damage threshold. There is a limited amount of research done in the area of fabrication and modeling of the rARSS.We extended the research area in the fabrication of rARSS and added a physical model which will be able to simulate the optical response of the fabricated rARSS and relate it to the fabrication parameters. The fused silica substrates were etched using inductively coupled plasma dry reactive ion etching (ICP DRIE) method. The etching parameters were investigated and optimized to get very high transmittance (nearly perfect) from Visible to Short-wave Infrared (SWIR) region.