Silicon‐photonic four‐mode triple‐band multiplexing device for hybrid wavelength/mode division multiplexing networks

• Published in: International journal of communication systems 2024-09, Vol.37 (13), p.n/a
• Main Authors: Tam Linh, Ho Duc, Hong Yen, Nguyen Thi, Duy Phuc, Vo, Buu Ngo, Trong Huynh, Duy Thang, Dao, Tuan, Nguyen Van, Cao Dung, Truong, Tan Hung, Nguyen
• Format: Article
• Language: English
• Subjects: Bandwidths; Channel capacity; Crosstalk; Directional couplers; Insertion loss; mode division multiplexing; Multiplexers; photonic integrated circuit; Photonics; planar lightwave circuit; Silicon; silicon on insulator; silicon photonics; Wave division multiplexing; Waveguides; Wavelength division multiplexing
• ISSN: 1074-5351; 1099-1131
• DOI: 10.1002/dac.5827

Summary While wavelength division multiplexing (WDM) technology combines several wavelengths onto a single waveguide, the technology of mode division multiplexing (MDM) allows many orthogonal modes of the same wavelength to operate simultaneously without interchannel crosstalk. Thus, the hybrid WDM and MDM network in which the two above‐mentioned techniques cooperate could give a several‐fold increase in the overall network capacity. Constructing this network requires hybrid wavelength‐and‐mode multiplexers, especially ones with high integration and complementary metal‐oxide‐semiconductor (CMOS) compatibility. In this paper, we propose a design of a four‐mode triple‐band multiplexer that is capable of multiplexing up to 12 separate optical signal flows by utilizing four eigenmodes (TE0, TE1, TE2, and TE3) and three‐wavelength windows, which center at 1310, 1490, and 1550 nm. The device is on silicon‐on‐insulator (SOI) platform, consisting of four butterfly‐shaped multimode interference (MMI) couplers, four directional couplers, and a 4×1 cascaded asymmetric Y‐junction coupler. Via numerical simulations, the proposed design is verified to be able to operate effectively on the three aforementioned bandwidth slots with an optical conversion efficiency of over 93% in all functions. Moreover, it exhibits insertion loss less than 1.5 dB and crosstalk smaller than −16 dB within 25 nm bandwidth at each wavelength window. These results can affirm the success of wavelength–mode combination, which leads to a massive improve in the channel capacity on the same optical multiplexing system for optical telecommunications and photonics on‐chip interconnections. Twelve data streams residing inside three different wavelength windows (centering at 1310, 1490, and 1550 nm) and four modes (TE0, TE1, TE2, and TE3) are successfully multiplexed with low insertion loss and minimal crosstalk.