Simulation tools for silicon photonics arrayed waveguide gratings

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Grating couplers with an integrated power splitter for high-intensity optical power distribution

In this letter, we present a fiber grating coupler with an integrated 16-way power splitter. The incoming light from the fiber is split immediately over 16 channels, and therefore, the total optical power is never confined in a single waveguide. This is of particular interest for silicon photonics platforms, because, here, high optical intensities can cause significant non-linear losses. The device has a total coupling efficiency that is similar to standard focusing grating couplers. Furthermore, a channel non-uniformity below 1.1 dB has been obtained. By studying the alignment sensitivity, we found that for high splitting uniformity, a careful positioning of the fiber is necessary. We also experimentally demonstrate that this device is indeed capable of handling high optical powers without introducing additional non-linear losses

Optimized silicon AWG with flattened spectral response using an MMI aperture

We demonstrate compact 12-channel 400 GHz arrayed waveguide grating wavelength demultiplexers (AWG) in silicon with a flattened spectral response. Insertion loss, crosstalk and non-uniformity are -3.29 dB, 17.0 dB and 1.55 dB, respectively. The flattened spectral response is obtained by using an optimized mode shaper consisting of a multi-mode interference coupler as the input aperture of the AWG. The ratio of the 1 dB bandwidth to the 10 dB bandwidth is improved by 50%, from 0.33 to 0.49 compared to a conventional AWG. The device size is only 560x350 mu m(2)

Compact silicon nitride arrayed waveguide gratings for very near-infrared wavelengths

In this letter, we report a novel high-index-contrast silicon nitride arrayed waveguide grating (AWG) for very near-infrared wavelengths. This device is fabricated through a process compatible with a complementary metal-oxide-semiconductor fabrication line and is therefore suitable for mass fabrication. The large phase errors that usually accompany high-index-platform AWGs are partly mitigated through design and fabrication adaptions, in particular the implementation of a two-level etch scheme. Multiple devices are reported, among which a 0.3-mm(2) device which, after the subtraction of waveguides loss, has a -1.2 dB on-chip insertion loss at the peak of the central channel and 20-dB crosstalk for operation similar to 900 nm with a channel spacing of 2 nm. These AWGs pave the way for numerous large-scale on-chip applications pertaining to spectroscopy and sensing