<div>To characterize the devices, a custom-built automated test setup [<cite class="squire-citation ltx_cite" data-bib-text="@incollection{Chrostowski,
	doi = {10.1017/cbo9781316084168.013},
	url = {http://dx.doi.org/10.1017/cbo9781316084168.013},
	publisher = {Cambridge University Press ({CUP})},
	pages = {381--405},
	author = {Lukas Chrostowski and Michael Hochberg},
	title = {Testing and packaging},
	booktitle = {Silicon Photonics Design}
}" data-bib-key="Chrostowski" contenteditable="false" style="cursor: pointer"><a class="au-cite-link" href="#Chrostowski">Chrostowski</a></cite>] with automated control software written in Python was used (<a href="http://siepic.ubc.ca/probestation">http://siepic.ubc.ca/probestation</a>). &nbsp;An Agilent 81600B tunable laser was used as the input source and Agilent 81635A optical power sensors as the output detectors. The wavelength was swept from 1500 to 1600 nm in 10 pm steps. &nbsp;A polarization maintaining (PM) fibre was used to maintain the polarization state of the light, to couple the TE polarization into the grating couplers [<cite class="squire-citation ltx_cite" data-bib-text="@article{Wang_2014,
	doi = {10.1364/oe.22.020652},
	url = {http://dx.doi.org/10.1364/oe.22.020652},
	year = 2014,
	month = {aug},
	publisher = {The Optical Society},
	volume = {22},
	number = {17},
	pages = {20652},
	author = {Yun Wang and Xu Wang and Jonas Flueckiger and Han Yun and Wei Shi and Richard Bojko and Nicolas A. F. Jaeger and Lukas Chrostowski},
	title = {Focusing sub-wavelength grating couplers with low back reflections for rapid prototyping of silicon photonic circuits},
	journal = {Opt. Express}
}" data-bib-key="Wang_2014" contenteditable="false" style="cursor: pointer"><a class="au-cite-link" href="#Wang_2014">Wang 2014</a></cite>]. &nbsp;A 90º rotation was used to inject light into the TM grating couplers [4]. &nbsp;A polarization maintaining fibre array was used to couple light in/out of the chip [<a href="http://www.plcconnections.com">www.plcconnections.com</a>].<br></div>