Angled multimode interferometer for bidirectional wavelength division (de)multiplexing

Abstract

We have demonstrated a bidirectional wavelength division (de)multiplexer (WDM) on the silicon-on-insulator platform using two 4-channel angled multimode interferometers (AMMIs) sharing the same multimode interference waveguide. An excellent match of the peak transmission wavelength of each channel between the two AMMIs was achieved. The input and output access waveguides were arranged in a configuration such that the propagation of light of one AMMI in the multimode interference waveguide suffered minimal perturbation by the input and output waveguides of the other AMMI. This type of device is ideal for the WDM system for datacom or telecom applications, e.g. an integrated optical transceiver, where the transmission wavelengths are required to match with the receiving wavelengths. The device also benefits from simple fabrication (as only a single lithography and etching step is required), improved convenience for the transceiver layout design, a reduction in tuning power and circuitry and efficient use of layout space. A low insertion loss of 3–4 dB, and low crosstalk of −15 to −20 dB, was achieved.

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“…However, the channel count can be increased by interleaving two devices [51]. Furthermore, the AMMI can be operated bidirectionally (BAMMI) so that any drift in the device performance either from fabrication tolerances or from temperature fluctuations during operation are balanced on both the multiplexor (MUX) and de-MUX [52], as shown in Figure 3. Photonic components with optical resonance are also commonly used in Si photonics platforms.…”

Interleaved bidirectional angled multimode interferometer for wavelength division (de)multiplexings

“…This type of device has a distinct advantage of low sensitivity to fabrication variations and ease of fabrication compared with other WDM devices, such as AWGs and echelle gratings. So far, this type of structure has already been applied in the material platform of silicon-on-insulator, 7 , 8 silicon nitride, 9 , 10 and LiNbO3 11 . However, they suffer from the drawbacks of a limited dispersive window, which results in a low channel count.…”

“…In particular, these problems can be amplified when this kind of device is applied to an optical transceiver for which the required the WDM devices increase by two or three times. Bidirectional propagation in one MW 8 is a useful approach to reducing the number of bulky AMMI structures; however, it is designed for achieving identical spectral response in two opposite directions. Thus, it is suitable for polarization diversity optical receivers rather than for interleaved WDM applications.…”

A Three Demultiplexer C-Band Using Angled Multimode Interference in GaN–SiO2 Slot Waveguide Structures

“…SOI nanophotonic devices may be fabricated on a BOX layer on top of a Si wafer substrate [25] with GaN-SiO 2 stacking such as demultiplexers [15] or splitters [21]. The multilayering process of the waveguide and the protective cladding consists of an e-beam lithography patterning, thin film deposition of GaN and SiO 2 using plasma enhanced chemical vapor deposition, alongside cleaning and etching of layer surfaces [26][27][28].…”