Sangsik Kim's findings were published in the peer-reviewed journal Optica.
Texas Tech University's Sangsik Kim, an assistant professor of electrical and computer engineering in the Edward E. Whitacre Jr. College of Engineering, recently was published in Optica. Optica is a monthly peer-reviewed, open-access scientific journal published by the Optical Society of America that covers the entire spectrum of theoretical and applied optics and photonics.
As described in the paper, "Exceptional Coupling in Photonic Anisotropic Metamaterials for Extremely Low Waveguide Crosstalk," Kim found a new coupling mechanism in photonic anisotropic metamaterials that can completely suppress the coupling between adjacent identical waveguides. The anisotropic metamaterial refers to an artificially engineered material whose anisotropic properties (i.e., material property that has directionality) can be controlled.
"While previous approaches tried to reduce the degree of coupling, this approach can completely cancel out the coupling effect," Kim said. "We called this phenomenon 'exceptional coupling.' We demonstrated this phenomenon on a typical silicon photonic chip and could suppress the crosstalk, which quantifies the power ratio of coupling, approximately 50 decibels compared to the case of standard strip waveguides.
"This translates approximately 500 times longer coupling length than the case of standard strip waveguides. To the best of our knowledge, this is the record-long coupling length demonstrated so far with such a short waveguide separation distance."
Kim said it's an honor to have his work published in Optica.
"Optica is the most respected journal in the Optical Society of America, which is the largest professional society in optics and photonics," he said. "The researchers in optics and photonics community highly appreciate the journals in Optica, so I'm really excited."
Texas Tech graduate students Md Borhan Mia (first author) and Syed Ahmed, electrical engineering, and Ishtiaque Ahmed, physics and astronomy, and Minghao Qi, a professor of electrical and computer engineering at Purdue University, are listed as co-authors on the paper.
Kim's paper is a result of the funding he received from the National Science Foundation. Click here to read more about Kim's work.