Ultra-Broadband Sources for Optical Coherence Tomography

DESCRIPTION (provided by applicant): The future of optical coherence tomography (OCT) in research and clinical medicine depends, to a large extent, on the development of better light sources. Portable sources with much wider bandwidths and higher single mode power are required to achieve the long standing goal of subcellular imaging in highly scattering tissue for detection and staging of endothelial cancers. Additionally, greater flexibility of center wavelength is required for assessment of tissue composition. This work aims to employ semiconductor wafer bonding technology to create high power, broadband, spectrally shaped, single-chip superluminescent diode (SLD) sources for OCT. This technology enables the in-line integration of several SLD sources comprising different composition emitter regions and operating at different spectral bands. The proposed geometry potentially allows superposition of 4-8 spectral bands with arbitrary weighting of each band, and promises to overcome the inherent losses in existing spectral synthesis techniques. The target specifications for these sources are greater than 200 nanometer (nm) bandwidth and greater than10 milliwatt (mw) fiber coupled power, out of a single chip. If successfully fabricated, this compact device will present researchers and emerging OCT manufacturers with unprecedented depth resolution in tissue imaging applications, enable spectroscopic OCT, and ideally increase the proliferation of high-resolution OCT research.