T-networks, Inc.

Aaron Bond

Ram Jambunathan

Newton C Frateschi

Won Jin Choi

John Kai Andersen

Liyan Zhang

Jiaming Zhang

John Kai Anderson

A grating dispersion compensator (GDC), including: a substrate; a dielectric grating layer; a planar waveguide; and a passivation layer. The dielectric grating layer may be formed on the substrate and includes a variation in refractive index. This variation in refractive index defines a grating period. The grating period may vary along the longitudinal axis of the GDC according to a predetermined function. A selected center wavelength and dispersion curve may be created. The chirp of the grating period may be controlled by current, voltage, temperature, or pressure. The planar waveguide is formed on the dielectric grating layer and includes an input/output (I/O) surface normal to the longitudinal axis of the planar waveguide. The passivation layer is formed on the planar waveguide. Alternatively, a GDC may be formed with the dielectric grating layer on top of the planar waveguide rather then beneath it.

Grating dispersion compensator and method of manufacture

A method of manufacturing a monolithic expanded beam mode electroabsorption modulator including a waveguide layer with a two expansion/contraction sections and an electroabsorption section arranged along a longitudinal axis. At least one patterned growth retarding layer is formed on the top surface of a substrate. The waveguide layer is formed on a portion of the top surface of the substrate by selective area growth and has an index of refraction different from the substrate. An electroabsorption portion of the waveguide layer has a thickness which is greater than thicknesses in its other portions. The semiconductor layer is formed on the waveguide layer and includes an index of refraction different from the waveguide. The waveguide and semiconductor layers are defined and etched to form the expansion/contraction and electroabsorption sections of the waveguide layer. Electrical contacts are formed, one electrically coupled to the substrate and another electrically coupled to the semiconductor layer.

Method of fabricating a monolithic expanded beam mode electroabsorption modulator

A method of tuning an electroabsorption modulator (EAM). A reference average power loss factor for light having a reference peak wavelength that is modulated by the EAM is provided. This loss factor is based on operation of the EAM using a reference bias voltage, a reference temperature, and a reference modulation signal which has a predetermined duty cycle. Input light is coupled into the EAM and modulated using a modulation signal which has the same duty cycle as the reference modulation signal. The input power of the input light and the average output power of light emitted from the EAM are measured. These input and average output powers are used to generate an average power loss factor. The average power loss factor is compared to the reference average power loss factor and the bias voltage and/or the temperature of the EAM are adjusted to reduce differences between these loss factors.

Method of tuning wavelength tunable electro-absorption modulators

A grating dispersion compensator (GDC), including: a substrate; a dielectric grating layer; a planar waveguide; and a passivation layer; is disclosed. The dielectric grating layer may be formed on the substrate and includes a variation in refractive index. This variation in refractive index defines a grating period. The grating period may vary along the longitudinal axis of the GDC according to a predetermined function. A selected center wavelength and dispersion curve may be created. The chirp of the grating period may be controlled by current, voltage, temperature, or pressure. The planar waveguide is formed on the dielectric grating layer and includes an input/output (I/O) surface normal to the longitudinal axis of the planar waveguide. The passivation layer is formed on the planar waveguide. Alternatively, a GDC may be formed with the dielectric grating layer on top of the planar waveguide rather than beneath it.

An exemplary monolithic stabilized monolithic transmissive active optical device, such as an electroabsorption modulator (EAM), a variable optical attenuator (VOA), or a semiconductor optical amplifier (SOA), with an output optical tap, is formed from: a substrate; a waveguide layer; a semiconductor layer. The waveguide layer is coupled to the substrate and includes an active medium, which interacts with a predetermined wavelength of light, and is responsive to an electric signal. The electric signal is applied between the substrate and the semiconductor layer. The waveguide layer includes an output optical tap section and an active section adjacent to the output optical tap section. These sections include portions of the active medium. Further embodiments of the present invention incorporate temperature as well as bias control to improve performance of exemplary monolithic transmissive active optical devices.

Method of stabilizing electro-absorption modulators (EAM's) performance by maintaining constant absorption with the use of intergrated tap couplers and method of manufacture

A monolithic single pass expanded beam mode active optical device includes: a substrate; a waveguide layer coupled to the top surface of the substrate; a semiconductor layer coupled to the waveguide layer; first and second electrodes for receiving an electric signal coupled to the substrate and the semiconductor layer, respectively. The waveguide layer includes a plurality of sublayers, forming a quantum well structure, which is responsive to the electric signal. The waveguide layer has three sections, two expansion/contraction sections and an active section, which extends between and adjacent to the two expansion/contraction sections. The thickness of at least one of the plurality of sublayers varies within the expansion/contraction portions of the quantum well structure. Possible interactions of the active region with the light include: absorption in the case of an electro-absorptive modulator and optical gain.

Monolithic expanded beam mode electroabsorption modulator

An exemplary monolithic stabilized monolithic transmissive active optical device, such as an electroabsorption modulator (EAM), a variable optical attenuator (VOA), or a semiconductor optical amplifier (SOA), with an output optical tap, includes: a substrate; a waveguide layer; a semiconductor layer. The waveguide layer is coupled to the substrate and includes an active medium, which interacts with a predetermined wavelength of light, and is responsive to an electric signal. The electric signal is applied between the substrate and the semiconductor layer. The waveguide layer includes an output optical tap section and an active section adjacent to the output optical tap section. These sections include portions of the active medium. Further embodiments of the present invention incorporate temperature as well as bias control to improve performance of exemplary monolithic transmissive active optical devices. Additional embodiments include exemplary methods of manufacture and methods of operation.

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Orefield, PA, United States of America

Aaron Bond