Flat-band superprism in photonic crystals

One of the key tasks in integrated photonics is the separation or demultiplexing of multiple different wavelength channels that are transported through the same waveguide.

One way to separate different wavelength is to use refraction in a prism and the photonic crystal community has taken this further, developing superprism. A superprism is a prism, but with stronger refraction than possible from the normal refractive index difference and so it can get a better wavelength separation in a smaller footprint.

In our work, we have now demonstrated a flat-band superprism that has a particularly constant refraction. So different wavelength channels, with a fixed wavelength spacing, will exit our superprism with almost identical spacing, making subsequent collection and processing easier.

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Dr Schulz awarded a Royal Society Research Grant

Good news everyone: Dr Schulz has been awarded a Royal Society research grant for his proposal “Tuneable, dielectric metasurfaces on epsilon-near-zero films”. Stay tuned for progress updates. And if you are interested in learning more about our work on metasurfaces incorporating epsilon-near-zero materials, why not visit the description of our research activities, read some of our previous papers on this topic (M. Z. Alam et al. Nature Photon 2018, S. A. Schulz et al. PRA 2016) or visit our friends from the synthetic optics group and learn about their work on epsilon-near-zero materials.

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Student Physics Society interview of Dr Schulz

Before the beginning of the summer, the student Physics society interviewed Dr Schulz for their Insight podcast series.

The full interview is now online. Listen to it if you want to know more about Dr Schulz, living in Canada and returning to St Andrews as a Lecturer.

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Thermally stable integrated laser

One problem in silicon photonics is that current integrated light sources are very sensitive to variations in the operating temperature.

Together with the Centre for Advanced Photonics & Process Analysis we have developed a hybrid laser with an external reflector based on silicon nitride gratings. The silicon nitride grating has a low thermo-optic coefficient and so our laser can operate unaffected over a large temperature range.

Our laser has a low threshold power, provides mW level output power and shows stable operation over a wide temperature range.

The full article is published in Applied Optics.

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PhC based tunable optical buffer

In collaboration with the Centre for Advanced Photonics and Process Analysis at the Cork Institute of Technology, we have demonstrated a low loss optical buffer based on photonic crystal cavities, demonstrating a record low loss per storage time. The delay can be tuned dynamically over a range of more than 150ps.

Scanning electron microscope image of the coupled photonic crystal cavities.

This work was published in the March 2018 edition of ACS Photonics.

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PhC based tunable optical buffer

In collaboration with the Centre for Advanced Photonics and Process Analysis at the Cork Institute of Technology, we have demonstrated a low loss optical buffer based on photonic crystal cavities, demonstrating a record low loss per storage time. The delay can be tuned dynamically over a range of more than 150ps.

Scanning electron microscope image of the coupled photonic crystal cavities.

This work was published in the March 2018 edition of ACS Photonics.

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