## All Theses

11-2022

Thesis

#### Degree Name

Master of Science (MS)

#### Department

Electrical and Computer Engineering

Judson Ryckman

William Harrell

Goutam Koley

#### Abstract

Planar optical devices offer a lightweight solution to the constraints found in traditional optical devices. While subwavelength patterning of optics offers attractive performance and size, traditional fabrication methods demand a trade-off between resolution and throughput that presents a significant hurdle for the widespread use of subwavelength devices. Nanoimprinting of refractive index (NIRI) is a novel fabrication method pioneered in previous work that offers promise in mitigating the throughput issues that hamstring traditional fabrication methods. However, NIRI has not been shown to impart full $2\pi$ phase control in planar optical devices, nor has a method for fabricating arbitrary designs using the NIRI process been demonstrated. Recently, we have developed a method by which arbitrary optics with full phase control may be designed and a corresponding NIRI stamp fabricated. Using this method, we have designed a series of optical devices to include blazed diffraction gratings, spiral phase plates, one-dimensional hyperbolic lenses, and Fresnel lenses. In order to vet this design method, two Fresnel lenses with $f_1 = 75\mu$m and $f_2 = 125\mu$m are simulated using finite difference time domain (FDTD). Results of ideal lenses as well as lenses with intentionally included fabrication errors are included. Additionally, the effects of reducing the digital resolution of NIRI lenses designed using this method are examined.

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