Little Optics Inc

Infinera Corporation

The United States of America As Represented by the Director of the

Lance G Joneckis

Oliver S King

Frederick Gorr Johnson

Sai T Chu

John V Hryniewicz

David M Gill

Daniel Mahgerefteh

Douglas Llewellyn Butler

Brent Everett Little

Julius Goldhar

The present invention provides a WDM optical system that includes a tunable filter for selecting one or more optical channels from a WDM optical signal. A portion of a WDM signal enters a first optical filter stage that exhibits a periodic transmission spectrum and possesses individually tunable filter elements. A second optical filter stage receives throughput from the first filter stage and has a periodic transmission spectrum and individually tunable filter elements. A controller electrically communicates with the optical filter to select individual optical channels from the portion of the wavelength division multiplexed optical signal received through the filter input port; each selected optical channel is output via a filter throughput port. In an exemplary embodiment, each tunable filter element is a micro-ring resonator and the micro-ring resonators in the first filter stage have a different free spectral range (FSR) than the micro-ring resonators of the second filter stage.

Wavelength division multiplexed optical communication system with rapidly-tunable optical filters

Devices and methods for the vapor deposition of amorphous, silicon-containing thin films using vapors comprised of deuterated species. Thin films grown on a substrate wafer by this method contain deuterium but little to no hydrogen. Optical devices comprised of optical waveguides formed using this method have significantly reduced optical absorption or loss in the near-infrared optical spectrum commonly used for optical communications, compared to the loss in waveguides formed in thin films grown using conventional vapor deposition techniques with hydrogen containing precursors. In one variation, the optical devices are formed on a silicon-oxide layer that is formed on a substrate, such as a silicon substrate. The optical devices of some variations are of the chemical species SiO N :D. Since the method of formation requires no annealing, the thin films can be grown on electronic and optical devices or portions thereof without damaging those devices.

Use of deuterated gases for the vapor deposition of thin films for low-loss optical devices and waveguides

An apparatus and method for measuring the spectral dependence of the Raman gain coefficient in optical fibers is presented. This approach measures the power level of Raman scattering in both a walk-off limited region and a physical fiber length limited region and, from these measurements, extracts the spectral dependence of the Raman gain coefficient. Access to these two regions is accomplished through control of the excitation pulse temporal width and relies on fiber dispersion to separate the excitation light from the Raman scattered light for short pulse widths. This approach measures the spectral dependence of the Raman gain without the necessity of absolute power measurement of the Raman scattered light, the need for a reference standard, or the need of a frequency tunable secondary optical source.

Measurement of Raman gain spectrum in optical fiber

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Severna Park, MD, United States of America

Lance G Joneckis