Near-Infrared Twelve-Channel Wavelength Division Demultiplexer on A Semi-insulating GaAs Substrate

Abstract

Wavelength division multiplexing (WDM) and demultiplexing (WDDM) devices have been under intensive research for the past 15 years. Many WDMs and WDDMs that use absorption and/or interference filters[1,2] and diffraction gratings[3-6] have been reported. Wavelength division multiplexing and demultiplexing is a promising technique for both optical communication and sensing systems. Multiplexing an array of signal carriers with different optical frequencies greatly enhances the transmission capacity and the application flexibility of an optical communication system. The dispersion characteristic of the diffraction grating provides an opportunity to employ WD(D)M devices for optical encoders[7,8] to detect both linear and rotational positions. We have developed four-channel visible (543, 594.1, 611.9 and 932.8 nm) , five-channel near IR (730, 750, 780, 810 and 840 nm), eight-channel (740, 750, 760, 770, 780, 790, 800, and 810nm) near IR and ten-channel near IR single-mode wavelength division demultiplexers using a graded index (GRIN) polymer waveguide in conjunction with a highly multiplexed waveguide hologram[9,10] Due to the index tunability of the polymer guide, the reported device can be implemented on high refractive index substrates such as GaAs and Si[11,12,13]