<title>Dispersion-enhanced wavelength division multiplexing</title>

Abstract

Wavelength division demultiplexer based on dispersive volume holograms and axial graded index (AGRIN) lenses is presented in this paper. The dispersive volume hologram was fabricated with DuPont photopolymer with two beam interference method. Close to 99 percent center wavelength diffraction efficiency was achieved and the dispersion property of a volume hologram was characterized with a mode-locked femto-second laser source. The experimental data were found to conform well with the theoretical derivations. Axial graded index (AGRIN) lenses have been sued as focusing elements to separate light with different incident angles after dispersive volume holograms. By using dispersive volume holograms and AGRIN lenses, a wavelength division demultiplexer with 1540 nm center wavelength and a 4 nm channel separation was demonstrated. By using two stacked holograms, light dispersion can be further enhanced up to five times. Therefore smaller devices and smaller channel separations can be realized.