Optical invisibility by refraction index matching... but revealed by fluorescence

Abstract

ABSTRACT:The phenomenon of optical invisibility associated to refraction index matching is demonstrated by a series of laboratory photographs. Two pyrex glass recipients, one placed inside the other, are filled subsequently with sunflower oil, resulting in the optical disappearance of the smaller recipient. However, the presence of the smaller recipient can be revealed by using the fluorescence properties of the sunflower oil when inciding with light from a simple laser pointer.Key words: Optics Education, Optics Experiments, Optical Cloaking, Fluorescence. RESUMEN:Mediante una serie de fotografías de laboratorio se demuestra el fenómeno de la invisibilidad óptica asociada al ajuste del índice de refracción. Dos recipientes de vidrio pyrex, introducidos uno en el interior del otro, se rellenan sucesivamente con aceite de girasol, observándose la desaparición aparente del recipiente de menor tamaño. Sin embargo, la presencia de este recipiente queda desvelada empleando las propiedades de fluorescencia del aceite de girasol cuando se incide con luz de un simple puntero láser.Palabras clave: Educación en Óptica, Prácticas de Óptica, Invisibilidad Óptica, Fluorescencia. REFERENCES AND LINKS / REFERENCIAS Y ENLACES[1] J.

Outreach activities on light science and technology at TecnOpto-UMH during the International Year of Light

“…Fluorescence of oil is then shown by illuminating it with a laser pointer, and this is used to reveal the presence of the "invisible" inner pyrex glass. Details of the experiment are given in [10]. Fluorescent pens and fluorescent cardboards illuminated with laser pointers of different wavelengths (red, green and violet) were used and (without mentioning photons) the relation between the "color" of light and energy is grasped.…”