The cascaded exponential-tapered multimode interference couplers based triplexer design for FTTH system

Design and performance analysis of InP/InGaAsP-MMI based 1310/1550-nm wavelength division demultiplexer with tapered waveguide geometry

“…Table 2 demultiplexer has low IL and high ER for both TE and TM polarization at wavelengths of 1330 nm and 1550 nm. In addition to that, the total size of the presented demultiplexer is about 370 μm × 3.4 μm which is much shorter than size reported by different works [9][10][11].…”

“…Several integrated−optical schemes have been proposed to perform the function, including conventional directional couplers [2], asymmetric Y−branching devices [3], asymmetric Mach− −Zehnder interferometers [4], MMI coupler [5][6][7], and multi− −core fibre [8]. Among them, MMI−based demultiplexers have attracted much attention because of compact size, low loss, larger fabrication tolerance and the broad bandwidth properties of MMI waveguides [9][10][11][12][13][14]. However, there is still possibility of further improving the quality of demulti− plexer in term of loss and power.…”

Silicon-based on-chip diplexing/triplexing technologies and devices

“…Since the output intensity of the 1310 nm wavelength has a large tolerance, the 1490 and 1550 nm wavelengths are only considered for defining the optimum length of one MMI. Furthermore, cascaded step-size MMI, based on pseudo self-imaging phenomenon, is proposed to separate three wavelengths [33][34][35]. A cascaded multimode waveguide is utilized to receive pseudo self-image of one wavelength and then outputs a self-image in this MMI.…”

“…Multiplexers utilizing MMI are generally based on the self-imaging phenomenon [29]. Other principles, such as pseudo self-imaging phenomenon [30][31][32][33][34][35] and dispersive self-imaging mechanism [36][37][38][39][40][41][42] are also proposed to realize wavelength multiplexers. Reflectors such as reflective Bragg gratings are further utilized to decrease the footprint of MMI [43][44][45].…”