2D beam shaping via 1D spatial light modulator using static phase masks.

Many emerging, high-speed, reconfigurable optical systems are limited by routing complexity when producing dynamic, two-dimensional (2D) electric fields. We propose a gradient-based inverse-designed, static phase-mask doublet to generate arbitrary 2D intensity wavefronts using a one-dimensional (1D) intensity spatial light modulator (SLM). We numerically simulate the capability of mapping each point in a 49 element 1D array to a distinct $7 \times 7$ 2D spatial distribution. Our proposed method will significantly relax the routing complexity of electrical control signals, possibly enabling high-speed, sub-wavelength 2D SLMs leveraging new materials and pixel architectures.

Role of refractive index in metalens performance.

Sub-wavelength diffractive optics, commonly known as metasurfaces, have recently garnered significant attention for their ability to create ultra-thin flat lenses with a high numerical aperture. Several materials with different refractive indices have been used to create metasurface lenses (metalenses). In this paper, we analyze the role of refractive index on the performance of these metalenses. We employ both forward and inverse design methodologies to perform our analysis. We found that, while high-refractive-index materials allow for extreme reduction of the focal length, for moderate focal lengths and numerical aperture (<0.6), there is no appreciable difference in the focal spot size and focusing efficiency for metalenses made of different materials with refractive indices ranging between 1.2 and 3.43 in forward design, and 1.25 and 3.5 in inverse design.

Simulation study of dual-space microscopy.

We explore the convergence of the dual-space microscopy (DSM) phase-recovery algorithm. DSM is an optical microscopy technique based on simultaneous observation of an object in the position and momentum spaces. We present one-dimensional (1D) simulations of this technique, demonstrating that the DSM technique is capable to resolve periodic and nonperiodic structures with a resolution well below the Rayleigh resolution limit. Using a simple and faster 1D version of the full 2D DSM algorithm, we simulated the DSM technique for thousands of different samples. Our results demonstrate that the DSM algorithm always converges rapidly to the correct optical disturbance.

Super-resolution imaging of photonic crystals using the dual-space microscopy technique.

We present an experimental implementation of the recently proposed dual-space microscopy (DSM), an optical microscopy technique based on simultaneous observation of an object in the position and momentum spaces, using computer-controlled hemispherical digital condensers. We demonstrate that DSM is capable of resolving structures below the Rayleigh resolution limit.