Temporal waveguides

Reflection at a temporal Boundary

Recently considerable interest has focused on a dynamic optical system whose refractive index changed in a dynamic fashion making it time dependent. Initially, this interest stemmed from the observation of adiabatic wavelength conversion in optical resonators. More recently, a space-time analogy has been exploited to make a time lens and use it for temporal imaging.

Evolution an optical pulse across a temporal boundary (Source: PRL 115, 183901)

My group has developed a time-transformation approach for studying light propagation inside a dynamic optical medium. Our approach transforms the electric field directly through a temporal mapping and does not require the slowly varying envelop approximation. The time-transformation approach provides valuable physical insight in the fields of optical signal processing and ultrafast optics.

Temporal Waveguides

Temporal waveguide made using two boundaries (dashed lines) that confine short optical pulses between them. Spectral trace shows large frequency shifts that occur during each temporal total internal reflection.

More recently we have studied the temporal analogs of spatial reflection and refraction occurring when the refractive index changes suddenly at a temporal boundary. We have also shown that the temporal analog of total internal reflection can be exploited to make a temporal waveguide that confines a pulse inside it. Since September 2019, this project is supported by a NSF grant.

For a list of recent publications, visit our publications page.