In optics, when a collection of nonlinear processes act together on a pump beam, the resulting spectral broadening of the original pump beam gives rise to a supercontinuum. Supercontinuum sources for optical coherence tomography are of great interest since they provide a broad bandwidth for high resolution and high-power imaging sensitivity. For commercial fiber-based supercontinuum systems, researchers use high pump powers to generate a broad bandwidth and customized optical filters to modulate the spectra. In a new report now published on Science Advances, Xingchen Ji and a research team in electrical engineering, biomedical engineering and applied physics at the Columbia University, New York, U.S., introduced a supercontinuum platform based on a 1 mm2 silicon nitride photonic chip for optical coherence tomography (OCT). The researchers directly pumped and efficiently generated a supercontinuum near 1300 nm and used the setup to image biological tissues and show the strong imaging performance of the device. The new chip will facilitate portable OCTs and integrated photonics during optical imaging studies.
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Source: Phys.org