Northrop Grumman Systems Corporation

Trw Limited

Ciena Corporation

Doyle T Nichols

Anastasios P Goutzoulis

Michael G Wickham

Timothy A Vang

Si Hyung Cho

Srinath Kalluri

Charles A Zmudzinski

Michael P Nesnidal

Robert W Lodenkamper

Gerald McAdoo

Larry Davis

Ilya Lyubomirsky

An optically-downconverting channelizer is disclosed for W-band detection. The channelizer includes an input waveguide configured to carry an inputted signal having a plurality of wavelengths including a desired wavelength and a plurality of ring resonators arranged in parallel and coupled at spaced apart locations along the input waveguide for receiving the inputted signal, wherein each of the plurality of ring resonators is configured to pass a selected wavelength signal to an output end. The channelizer further includes a control waveguide that carries a second signal having a wavelength that differs from the desired wavelength by a predetermined amount, and a plurality of detectors coupled to respective output ends of the ring resonators, the plurality of detectors configured to produce channelized RF output signals representative of desired RF bands.

Optical channelizer for W-band detection

The present invention is directed toward a laser wavelength locking scheme suitable for incorporation into WDM systems having channel spacings of 25 GHz or less. In a preferred embodiment, light output from the laser is supplied to a filtering element, such as an in-fiber Bragg grating or an etalon, and photodetectors are used to sense light transmitted through and either reflected by the filtering element or input to the filtering element. A measured ratio corresponding to a quotient of the photocurrents generated by the photodetectors is calculated and compared to a desired ratio corresponding to a measured temperature of the filtering element when the filtering element transmits the desired wavelength to be locked. Based on the comparison of the desired and measured ratios, a temperature error value is calculated which is used to adjust the laser temperature, as well as the laser wavelength. Accordingly, the temperature of the filtering element, for example, influences the laser temperature, so that wavelength variations stemming from temperature induced changes in the filtering element and other components in the laser package can be compensated, and the output wavelength can remain substantially fixed.

Wavelength locking scheme and algorithm for ultra-high density WDM system

A waveguide ( ) is provided having a two-dimensional optical wavelength Bragg grating ( ) embedded within a semiconductor laser medium ( ). More particularly, the waveguide ( ) includes an active region ( ) sandwiched between n-doped and p-doped cladding layers ( ). The two-dimensional Bragg grating ( ) is formed in the active region ( ). Upper and lower electrodes ( ) are defined on opposite sides of the cladding layers ( ) to complete the waveguide structure ( ). The two-dimensional grating ( ) provides simultaneous frequency selective feedback for mode control in both the longitudinal and lateral directions.

High power single mode semiconductor lasers and optical amplifiers using 2D Bragg gratings

An electroabsorptive modulator (EAM) for providing RF modulation of optical inputs signals. The EAM is formed as a semiconductor waveguide on a semiconductor substrate with an optical input port and an optical output port and electrical contacts for connection to the RF input. The configuration of the waveguide portion of the EAM is optimized to provide a modal match with the particular optical device to which the EAM is to be connected, for example, an optical fiber. By optimizing the modal match between the EAM and the optical device to which the EAM is connected, the optical insertion losses are minimized thereby improving the overall performance of the optical system. The device is formed from a plurality of quantum wells selected to compensate for the increased mode field dimensions.

Expanded mode wave guide semiconductor modulation

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Ellicott City, MD, United States of America

Doyle T Nichols