Multi-scale numerical analysis for optical functions of cuticle nanostructures on a firefly light organ

Abstract

The research of bioinspired photonic structures has revealed a variety of optical devices, and it has been used in many areas due to the optimized design. These photonic structures are limited in vision or structural color. The bioluminescence photonic structures are expected to take high performance in industrial market such as display and illumination. However, these structures have not been studied a lot. In this work, cuticle nanostructures on a firefly light organ are discovered, and optical functions of cuticle nanostructures are investigated by using multi-scale numerical analysis. The structural and optical properties of firefly light organ are investigated. The structure properties are separately measured in surface and cross-section. The main tool is scanning electron microscope (SEM) and the other tools are microtome, microscope, and image processing. The geometrical parameters such as width, length, height, orientation, and periods of patterns are 200nm, $1.2\mum$, 100nm, 80-100 degrees range, and 250-260nm, respectively. A spectroscope is used for measuring the spectrum. The peak values are 563nm and 569nm in males and females, respectively. The mean value is 566nm. The multi-scale numerical analysis combines the ray tracing and finite differential time domain (FDTD) methods to analyze the optical functions of cuticle nanostructures on a firefly light organ. The FDTD method solves sub-micron analysis and the ray tracing method calculates large scale analysis. The combination of these two methods is useful for the analysis of the nanostructures on a large curved surface due to weaknesses complement. The multi-scale optical simulation is an appropriate method for the analysis of cuticle nanostructures on a firefly light organ. Wide angle illumination and high extraction efficiency are the expected effects of the cuticle nanostructures on a firefly light organ. The two assumptions are based on the grating structure effects. The multi-scale nume...