Photonic crystal waveguides for coarse-selectivity devices

Photonic-Crystal Demultiplexer With Improved Crosstalk by Second-Order Cavity Filtering

“…This latter couples the modes whose dominant propagation constant differ by , being the lattice constant of the PhC, coinciding with the waveguide periodicity in the preferred case of a triangular lattice of holes with waveguide along the dense row, also known as the K direction. The effects of zone-folding and the applicability of coupled mode theory to this situation has been amply demonstrated in previous work [10], [12], [19]- [21].…”

“…The demultiplexed signal is the intentional leakage of the HOM mode across a thinned barrier of the photonic crystal waveguide [9]- [12], [14], [15]. The simple duplication of the same waveguide after the barrier would not only lead to an extra resonance, but also to the unwanted channeling of power in the fundamental mode (FM) of this second waveguide.…”

“…Such an option was inserted in [22] in a related context and was, in the present context, pictured in [12] and [17]. These adjacent waveguides are named WG1 (input of signal) and WG2 (filtering).…”

“…We proposed in [12] and [17] a twin waveguide structure in order to implement the same principle for our photonic crystal waveguide demultiplexing approach, whereby the second waveguide acts as the extra filter element (see Fig. 2).…”

Integration of grating couplers with a compact photonic crystal demultiplexer on an InP membrane

“…The DeMUX is a membrane version of the device already described in [9][10][11][12] for conventional InP heterostructures. It exploits energy transfer caused by intermodal coupling at mini-stop-bands (MSBs) [13,14] of a multimode PhC waveguide.…”