On-chip Non-Blocking 4 × 4 and 8 × 8 Photonic Switches Using MMI-MZI Configuration for Next-Generation Data Center Networks

The advancement of future photonic integrated circuits for data center networks relies crucially on the development of highly efficient, low-power, and compact switches. This paper presents the design of non-blocking 4×4 and 8×8 silicon photonics switches intended using Multimode Interferometer (MMI)-Mach-Zehnder interferometer (MZI) structures. These proposed switches consist of 2×2 MMI-MZI switches realized by changing the phase of an optical signal using the thermo-optic effect. At 1550 nm, the proposed 2×2 switch exhibits an insertion loss of 0.04 dB and crosstalk of < 39.95 dB. Similarly, the C-band showcases an insertion loss of < 0.06 dB and crosstalk of < -33 dB. To support complex network topologies and enhance network efficiency, a data center network necessitates a higher quantity of port switches. The results show that at 1550 nm, the insertion loss for the 4×4 and 8×8 switches is 0.47 dB and 1.02 dB, respectively. Furthermore, the insertion loss for the C-band is < 0.50 dB and < 1.5 dB, respectively. The switches exhibit crosstalk of -37.59 dB and -34.67 dB at 1550 nm, respectively. Additionally, they demonstrate crosstalk of < -30 dB for the C-band. This suggests the potential for further scalability in terms of port counts. The switches are designed using the eigenmode expansion method, and the micro heater is designed with a finite element heat transfer solver. These advantages and excellent performance make the device a promising candidate for use in advanced communication systems and photonic integrated circuits.