Finisar Corporation

Neophotonics Corporation

Sycamore Networks, Inc.

Future Wei Technologies, Inc.

Jianying Zhou

Yuheng Lee

Daniel Mahgerefteh

Xueyan Zheng

Richard A Barry

Yan Yang Zhao

Parviz Tayebati

Kevin John McCallion

Bernd Huebner

Hongmin Chen

Murat Azizoglu

Vincent Lixiang Bu

Mark J Dayel

Wen-Jr Jiang

Yu Sheng Bai

Christopher R Cole

Xiao Andy Shen

Yasuhiro Matsui

Michael Deutsch

Eric Arthur Swanson

Hongbing Lei

Naimish Patel

Derek E Spock

Chunlei Liao

Yupeng Song

Yanyang Zhao

Guoxi Sun

John Z Jiang

Improved dither detection, measurement, and voltage bias adjustments for an electro-optical modulator are described. The electro-optical modulator generally includes RF electrodes and phase heaters interfaced with semi-conductor waveguides on the arms of Mach-Zehnder interferometers, where a processor is connected to output a bias tuning voltage to the electro-optical modulator for controlling optical modulation. A variable gain amplifier (VGA) can be configured with AC coupling connected to receive a signal from a transimpediance amplifier (TIA) that is configured to amply a photodetector signal from an optical tap that is used to measure an optical signal with a dither signal. The analog to digital converter (ADC) can be connected to receive output from the VGA. The processor can be connected to receive the signal from the ADC and to output the bias tuning voltage based on evaluation of the signal from the tap.

Method and apparatus for bias control with a large dynamic range for Mach-Zehnder modulators

Optical modulators with semiconductor based optical waveguides interacting with an RF waveguide in a traveling wave structure. The semiconductor optical waveguide generally comprise a p-n junction along the waveguide. To reduce the phase walk-off between the optical signal and the RF signal, the traveling wave structure can comprise one or more compensation sections where the phase walk-off is reversed. The compensation sections can comprise a change in dopant concentrations, extra length for the optical waveguide and/or extra length for the RF waveguide. Corresponding methods are described.

Method and apparatus for phase-matched optical and RF wave propagations for semiconductor-based MZM modulators

Method and apparatus for phase-matched optical and RF wave propagations for semiconductor based MZM modulators

An apparatus comprises: a first input tap; a first optical modulator coupled to the first input tap; a first output tap coupled to the first optical modulator so that the first optical modulator is positioned between the first input tap and the first output tap; and a controller indirectly coupled to the first input tap and the first output tap.

Optical modulator bias locking

Thermal chirp compensation in a chirp managed laser. In one example embodiment, a laser package including a laser and an optical spectrum reshaper configured to convert frequency modulated optical signals from the laser into an amplitude modulated optical signals is provided. A thermal chirp compensation device is in communication with the laser package and a laser driver. The thermal chirp compensation device includes means for generating bias condition and temperature specific thermal chirp compensation signals that each corresponds to a predetermined level of thermal chirp that is induced in the laser by operating the laser at a particular bias condition and temperature.

Thermal chirp compensation in a chirp managed laser

In one example embodiment, a coplanar waveguide signal transition element transitions high-speed signals between vertically stacked coplanar waveguide transmission lines. The signal transition element comprises one or more dielectric layers and a plurality of electrically conductive vias extending through at least a portion of the one or more dielectric layers. The vias include one or more signal vias and one or more ground vias that are configured to transition signals between the vertically stacked coplanar waveguide transmission lines. The signal transition element also comprises a ground plane disposed within the one or more dielectric layers and electrically coupled to the one or more ground vias. The ground plane has one or more openings through which the one or more signal vias respectively pass.

Vertical quasi-CPWG transmission lines

Thermal chirp compensation in a chirp managed laser. In one example embodiment, a method for thermal chirp compensation in a chirp managed laser (CML) includes several acts. First, a first bias condition and temperature is selected. Next, a first thermal chirp compensation signal is generated. Then, the laser is driven by biasing a first input drive signal with the first thermal chirp compensation signal. Next, a second bias condition and temperature is selected. Then, a second thermal chirp compensation signal is generated. Finally, the laser is driven by biasing a second input drive signal with the second thermal chirp compensation signal.

The frequency chirp modulation response of a directly modulated laser is described using a small signal model that depends on slow chirp amplitude s and slow chirp time constant &#x3c4;. The small signal model can be used to derive an inverse response for designing slow chirp compensation means. Slow chirp compensation means include electrical compensation, optical compensation, or both. Slow chirp electrical compensation can be implemented with an LR filter or other RF circuit coupled to a direct modulation source (e.g., a laser driver) and the directly modulated laser. Slow chirp optical compensation can be implemented with an optical spectrum reshaper having a rounded top and relatively large slope (e.g., 1.5-3 dB/GHz). The inverse response can be designed to under-compensate, to produce a flat response, or to over-compensate.

Slow chirp compensation for enhanced signal bandwidth and transmission performances in directly modulated lasers

In one example embodiment, a high-speed transponder includes a printed circuit board having a set of coplanar high-speed traces, and a high-speed circuit and a package mounted to the printed circuit board. The package includes an outside housing and a second high-speed circuit positioned inside the housing. The high-speed transponder also includes a high-speed feed thru which includes an inside coplanar structure positioned inside the housing, a strip line structure positioned through the housing, and an outside coplanar structure positioned outside the housing. The second high-speed circuit is operably coupled to the inside coplanar structure, which is operably coupled to the strip line structure, which is operably coupled to the outside coplanar structure, which is operably coupled to the first high-speed circuit via the set of coplanar high-speed traces. The signal plane of the outside coplanar structure is flipped with respect to a signal plane of the inside coplanar structure.

High-speed interconnects

In one example, a hybrid surface mountable package includes a housing at least partially defining a sealed cavity, two microwave integrated circuits (MIC) chips positioned inside the sealed cavity, and a very-high-speed interconnect connecting the two MIC chips to each other. The very-high-speed interconnect includes strong coupling co-planar waveguide (CPWG) transmission lines.

Hybrid surface mountable packages for very high speed integrated circuits

An embodiment of the invention includes a high speed feed thru connecting a first circuit outside a housing to a second circuit inside the housing. The first circuit includes a first high speed integrated circuit chip and the second circuit includes a second high speed integrated circuit chip or optoelectronic device. The high speed feed thru includes an inside coplanar structure positioned at least partially inside the housing, the inside coplanar structure connected to the second circuit. The high speed feed thru also includes an outside coplanar structure positioned at least partially outside the housing, the outside coplanar structure connected to the first circuit. A material separates the inside coplanar structure and the outside coplanar structure. At least one guided via extends through the material, connecting the inside coplanar structure and the outside coplanar structure.

Feed thru with flipped signal plane using guided vias

In one example embodiment, a high-speed package includes first and second layers and a multi-channel non-coplanar interconnect. The first layer includes first and second sets of coplanar transmission lines. The second layer includes third and fourth sets of coplanar transmission lines. The multi-channel non-coplanar interconnect includes first and second channels. The first channel connects the first set of transmission lines to the third set of transmission lines. The second channel connects the second set of transmission lines to the fourth set of transmission lines.

Non-coplanar high-speed interconnects

An optical transmitter comprising: wherein the electrical switch takes an input electrical digital signal and selectively directs it to a specific laser element in the DFB laser array.

Growing community of inventors

Acton, MA, United States of America

Jianying Zhou