Optical performance test and validation of microcameras in multiscale, gigapixel imagers.

Wide field-of-view gigapixel imaging systems capable of diffraction-limited resolution and video-rate acquisition have a broad range of applications, including sports event broadcasting, security surveillance, astronomical observation, and bioimaging. The complexity of the system integration of such devices demands precision optical components that are fully characterized and qualified before being integrated into the final system. In this work, we present component and assembly level characterizations of microcameras in our first gigapixel camera, the AWARE-2. Based on the results of these measurements, we revised the optical design and assembly procedures to construct the second generation system, the AWARE-2 Retrofit, which shows significant improvement in image quality.

Autofocus for a multiscale gigapixel camera.

In recent studies, the advanced wide field of view architectures for image reconstruction and exploitation (AWARE) multiscale camera, which is composed of a monocentric objective lens and an array of microcameras, was developed for the realization of snapshot wide field of view and high resolution imaging. This paper describes accelerated autofocus (AF) methods for the AWARE system based on a hierarchical spatial algorithm and an iterative temporal algorithm. In the algorithms, sensor positions of each microcamera are hierarchically scanned with contrast detection to effectively search for a focusing distance. The positions are then updated iteratively for dynamic scenes using temporal information. The algorithms are theoretically analyzed and experimentally demonstrated. The developed AF methods can be used for the realization of the temporal gigapixel imaging by the AWARE system.

Strongly dipolar Bose-Einstein condensate of dysprosium.

We report the Bose-Einstein condensation (BEC) of the most magnetic element, dysprosium. The Dy BEC is the first for an open f-shell lanthanide (rare-earth) element and is produced via forced evaporation in a crossed optical dipole trap loaded by an unusual, blue-detuned and spin-polarized narrowline magneto-optical trap. Nearly pure condensates of 1.5 × 10(4) (164)Dy atoms form below T = 30 nK. We observe that stable BEC formation depends on the relative angle of a small polarizing magnetic field to the axis of the oblate trap, a property of trapped condensates only expected in the strongly dipolar regime. This regime was heretofore only attainable in Cr BECs via a Feshbach resonance accessed at a high-magnetic field.

Trapping ultracold dysprosium: a highly magnetic gas for dipolar physics.

Ultracold dysprosium gases, with a magnetic moment 10 times that of alkali atoms and equal only to terbium as the most magnetic atom, are expected to exhibit a multitude of fascinating collisional dynamics and quantum dipolar phases, including quantum liquid crystal physics. We report the first laser cooling and trapping of half a billion Dy atoms using a repumper-free magneto-optical trap (MOT) and continuously loaded magnetic confinement, and we characterize the trap recycling dynamics for bosonic and fermionic isotopes. The first inelastic collision measurements in the few partial wave, 100 microK-1 mK, regime are made in a system possessing a submerged open electronic f shell. In addition, we observe unusual stripes of intra-MOT <10 microK sub-Doppler cooled atoms.