Deoxyribonucleic acid (DNA) has been a remarkable material in the development of optoelectronic devices for granted these days. In this research, we report on an optical phenomenon of DNA structures grown by a self-assembly process. Discrete 2D nanocrystal structures of DNA were prepared on a light-guiding substrate. The high evanescent field interaction between the guided light supplied via D-shaped optical fiber and DNA monolayers enabled the systematic investigating of the optical properties of DNA nanocrystal structures. In particular, light guided down the fiber and received by an optical spectrum analyzer enabled spectral analysis, while morphology studies of the self-assembly DNA were performed by atomic force microscopy.
We report a unique technique to generate a liquid periodic structure whose unit volume is as low as a few hundred
femto-liter. Liquids such as water, toluene and ethanol were filled in a hollow optical fiber (hole diameter of 8 and
13μm), which were locally heated by a traversing miniature electric furnace. The periods between droplets could be
varied flexibly in the range from 14 to 100μm and the volume of individual droplet was in the range from 112 to 845
femto-liter. We also fabricated the periodic liquid droplets with quantum dots, whose fluorescence was successfully
measured in each droplet. These periodic liquid droplets could serve as flexible liquid long period fiber grating for the
hollow optical fiber, which can be further applied in various mechanical and bio-chemical sensors