Ultrasmall in-plane demultiplexer enabled by an arrayed one-dimensional photonic crystal nanobeam cavity

Abstract

We propose a design for silicon-on-chip integrated eight-channel wavelength division multiplexing (WDM) demultiplexer, which consists of parallel-arrayed one-dimensional (1-D) photonic crystal nanobeam cavities (PCNCs) with high-Q over 10 5 and large free spectral range of ∼200 nm. To the best of our knowledge, this is for the first time that a 1-D PCNC-based demultiplexer is presented. The performance of the device is investigated theoretically by using three-dimensional finite-difference time-domain method. To enable eightchannel parallel arrayed 1-D PCNCs to be coupled to on-chip optical networks for higher integration and multiplex application, an 1 × 8 taper-type equal optical power splitter is used to connect all channels simultaneously. The total device footprint is as small as 12 μm × 15 μm (width × length), which is decreased by five times compared to that per channel in the recent two-dimensional (2-D) PC-based demultiplexer. Moreover, the average channel spacing smaller than 115 GHz is achieved, which is more than two times smaller than that of 2-D PC nanocavity devices, demonstrating that the arrayed nanocavities have the potential for developing ultracompact 100-GHz spaced filters in a dense WDM system. Thus, we believe that the results demonstrated in this work is promising for the future on-chip photonics integrated circuits and optical communication systems.

Integrated fluorescence excitation, collection, and filtering on a GaN waveguide chip

“…Therefore, the fluorescence can be excited and collected more effectively in the slot [14,17] . On the other hand, one-dimensional photonic crystal 1D PC waveguides could be used as on-chip filters [18,19] , which possess smaller footprints and smooth geometry for on-chip integration. Therefore, these configurations pave the way for more efficient fluorescence excitation, collection, and even on-chip filtering to realize an integrated on-chip device.…”