Reflection from a free carrier front via an intraband indirect photonic transition

The reflection of light from moving boundaries is of interest both fundamentally and for applications in frequency conversion, but typically requires high pump power. By using a dispersion-engineered silicon photonic crystal waveguide, we are able to achieve a propagating free carrier front with only a moderate on-chip peak power of 6 W in a 6 ps-long pump pulse. We employ an intraband indirect photonic transition of a co-propagating probe, whereby the probe practically escapes from the front in the forward direction. This forward reflection has up to 35% efficiency and it is accompanied by a strong frequency upshift, which significantly exceeds that expected from the refractive index change and which is a function of group velocity, waveguide dispersion and pump power. Pump, probe and shifted probe all are around 1.5 µm wavelength which opens new possibilities for "on-chip" frequency manipulation and all-optical switching in optical telecommunications.

Subjects

optical materials and structures

optics and photonics

slow light

DDC Class

500: Naturwissenschaften

530: Physik

620: Ingenieurwissenschaften

Funding(s)

Indirekte photonische Übergänge zur Lichtsteuerung in integrierter Photonik

Relativistische photonische Bandlückenspiegel in der integrierten Optik

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

s41467-018-03862-0.pdf

Size

1.15 MB

Format

Adobe PDF

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Reflection from a free carrier front via an intraband indirect photonic transition