Cascaded Optical Interleaver

  • Description

    This application example underlines the principal limitation of pure time-domain modeling (TDM) of large-scale photonic integrated circuits (PICs). It is illustrated with a device composed by several cascaded interleavers (Figure 1). Using pure TDM, each PIC element is described by its own FIR filter. Input signals are filtered sample-by-sample by each PIC element. This technique is quite accurate within a certain bandwidth; however, it is always accompanied by an intrinsic deterioration near the edges of the simulated signal bands (Figure 2). We overcome this problem with the novel hybrid time-and-frequency modeling domain (TFDM) approach [1] where FIR filters are designed not for each individual passive PIC element but only for compound passive devices (Figure 3).

  • Typical Results

    With the TFDM technique, the accumulation of inaccuracies of FIR filters is dramatically improved. This implies that a larger time step can be used to achieve similar results, and the simulation time can thus be reduced. This fact is demonstrated in Figure 4: similar performances are achieved for a single interleaver and cascaded structure of 15 interleavers.

  • Further Information

    Keywords: Interleaver, SMATRIX, Time-and-frequency domain, Photonic Integrated Circuits, PICs

    Similar demonstrations are available in VPIComponentMaker Photonic Circuits and on the VPIphotonics Forum.

    [1] S. F. Mingaleev, E. Sokolov, C. Arellano, I. Koltchanov, and A. Richter, "Hybrid time-and-frequency-domain approach for modeling photonic integrated circuits", NUSOD, paper ThA4 (2011)

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