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We describe techniques that enable fabrication of a new class of photonic devices based on free UH-Q microresonators. Preliminary results show that free silica microtoroids with Qs above 30 million can be fabricated and transferred to different platforms for integration with a variety of photonic devices. Very high-order microring resonator filters for WDM(More)
An erbium-doped microlaser is demonstrated utilizing SiO 2 microdisk resonators on a silicon chip. Passive microdisk resonators exhibit whispering-gallery-type modes ͑WGM's͒ with intrinsic optical quality factors of up to 6 ϫ 10 7 and were doped with trivalent erbium ions ͑peak concentration ϳ3.8ϫ 10 20 cm −3 ͒ using MeV ion implantation. Coupling to the(More)
PURPOSE To investigate the cause of axial eye motion artifacts that occur in optical coherence tomography (OCT) imaging of the retina. Understanding the cause of these motions can lead to improved OCT image quality and therefore better diagnoses. METHODS Twenty-seven measurements were performed on 5 subjects. Spectral domain OCT images at the macula were(More)
One of the present challenges in optical coherence tomography (OCT) is the visualization of deeper structural morphology in biological tissues. Owing to a reduced scattering, a larger imaging depth can be achieved by using longer wavelengths. In this work, we analyze the OCT imaging depth at wavelengths around 1300 nm and 1600 nm by comparing the scattering(More)
The photoluminescence decay characteristics of silicon nanocrystals in dense ensembles fabricated by ion implantation into silicon dioxide are observed to vary in proportion to the calculated local density of optical states. A comparison of the experimental 1 / e photoluminescence decay rates to the expected spontaneous emission rate modification yields(More)
Although it is generally accepted that oxygen-quenched phosphorescence decay traces can be analyzed using the exponential series method (ESM), its application until now has been limited to a few (patho)physiological studies, probably because the reliability of the recovered oxygen tension (pO(2)) histograms has never been extensively evaluated and lacks(More)
—The use of integrated optics for Optical Coherence Tomography (OCT) can offer significant cost reductions and new applications. We designed, fabricated, and characterized Silicon oxynitride (SiON) elliptic couplers that are used to focus light from a chip into the off-chip environment. Fizeau-based OCT measurements are performed and compared to(More)
We demonstrate monolithic 160-µm-diameter rare-earth-doped microring lasers using silicon-compatible methods. Pump light injection and laser output coupling are achieved via an integrated silicon nitride waveguide. We measure internal quality factors of up to 3.8 × 10 5 at 980 nm and 5.7 × 10 5 at 1550 nm in undoped microrings. In erbium-and ytterbium-doped(More)
—Silicon oxynitride-based arrayed waveguide grating (AWG) spectrometers were designed for on-chip spectral-domain optical coherence tomography (OCT) systems and Raman spectroscopy of the skin. A novel geometrical layout for Raman spectroscopy was introduced to reduce loss. Measurements show that integrated optics has a good potential for miniaturizing(More)