Angled multimode interferometer for bidirectional wavelength division (de)multiplexing.

Y Hu,G Z Mashanovich,A Z Khokhar,F Y Gardes,S Stanković,C J Mitchell,G T Reed,D J Thomson,J Soler Penades

doi:10.1098/rsos.150270

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.

Highlights

Wavelength divisionmultiplexers (WDMs) are key components for integrated optical transceivers
One can see that an excellent match in the central wavelengths of the 4 channels from both directions is achieved with a mismatch between the corresponding channels of less than 0.1 nm
Localized electrical heaters are used for this purpose in silicon photonics

Summary

Introduction

Wavelength division (de)multiplexers (WDMs) are key components for integrated optical transceivers. In a typical integrated optical transceiver, there are two wavelength matching WDMs, where one is for wavelength multiplexing (MUX) in the transmitter part and the other is for wavelength demultiplexing (DEMUX) in the receiver part. In a silicon photonics solution, a further DEMUX may be required to enable multi-wavelength light from an external source to be coupled to the chip via a single fibre, with the different wavelengths separated on-chip.

Methods

Results

Conclusion