arXiv subjects

D. Ryan Sheffield

Publications and source records attributed to D. Ryan Sheffield.

2 recordsLinked to original sources

arXiv2025

Scanning apparatus to detect the spectral directivity of optically-emissive materials

An apparatus that records the optical spectrum of emissive materials as a function of the polar coordinate angles is reported. The ability for the device to characterize the directive gain of a light source over the optical spectrum is demonstrated. The angular emission profile of an electrically driven LED with a hemispherical diffuser cap was measured. In addition, the device was used to characterize optically pumped materials exhibiting both fluorescence and amplified spontaneous emission (ASE), demonstrating its versatility for diverse emissive systems.

physics.optics↗

arXiv2024

Neon tetra fish (Paracheirodon innesi) as farm-to-optical-table Bragg reflectors

Iridophore networks in the skin of neon tetra fish are investigated for use as biologically sourced, tunable, Bragg reflector arrays. This paper reports on a method for immediate and fast post-processing of tissue to modify the structural color of iridophores found in the lateral color stripe. Conditions for fixation as well as the environment post-fixation to improve longevity of the structural color are also presented. Recent results from attempts to further increase the lifetime of post-mortem iridophore color through infiltration and embedding in low-acid glycol methacrylate are also discussed.

physics.optics↗