Avago Technologies Fiber IP (Singapore) Pte. Ltd

Avago Technologies General IP (Singapore) Pte. Ltd.

Other

Avago Technologies Fiber IP Pte Ltd.

Agilent Technologies, Inc.

Frederick W Miller

Michael Allen Robinson

Takashi Hidai

Gideon Z Romm

Randall P Clark

Laurence Ray McColloch

Peter Henry Mahowald

James A Matthews

Ronald T Kaneshiro

Janet L Yun

Jing Wang

David G Cunningham

Eng-Ho Soo

Heng Seng Alvin Low

An active optical cable is provided that incorporates a power management solution. The AOC has plugs are configured to mate with respective USB sockets. The AOC is used to interconnect a USB host with a USB device. To the USB host and to the USB device, the AOC appears to be a standard USB electrical cable. Each of the plugs of the AOC has an optical-to-electrical and an electrical-to-optical (OE/EO) conversion module that converts electrical USB signals output from the USB host or USB device into optical signals and converts optical signals carried on the optical fibers of the AOC into electrical USB signals. The plugs include controllers that monitor certain conditions of the AOC and that select the power levels to be used in the plugs based on detected conditions.

Method for performing power management in an active optical cable (AOC)

A parallel optical transceiver module is provided that has a balanced laser driver arrangement. The balanced laser driver arrangement of the invention includes at least two laser diode driver ICs, which preferably are located on opposite sides of a laser diode IC. Each laser diode driver IC drives a subset (e.g., half) of the total number of laser diodes of the laser diode IC. Because each laser diode driver IC drives a subset of the total number of laser diodes of the laser diode IC, the pitch (i.e., distance) between the high-speed signal pathways within the laser diode driver ICs can be increased. Increasing the pitch between the high-speed signal pathways provides several advantages, including, for example, reducing the potential for electrical cross-talk and inductive coupling between adjacent wire bonds that connect the output driver pads on the driver IC to the respective input pads on the laser diode IC.

Parallel optical transceiver module having a balanced laser driver arrangement

An active optical cable is provided that incorporates a power management solution. The AOC has plugs that are configured to mate with respective USB sockets. The AOC is used to interconnect a USB host with a USB device. To the USB host and to the USB device, the AOC appears to be a standard USB electrical cable. Each of the plugs of the AOC has an optical-to-electrical and an electrical-to-optical (OE/EO) conversion module that converts electrical USB signals output from the USB host or USB device into optical signals and converts optical signals carried on the optical fibers of the AOC into electrical USB signals. The plugs include controllers that monitor certain conditions of the AOC and that select the power levels to be used in the plugs based on detected conditions.

Active optical cable (AOC) and a method and apparatus for performing power management in the AOC

An open loop gain adjustment method and apparatus are provided for adjusting the gain of a TIA of an optical RX module based on measurements of the BER of the optical link in which the optical RX module is employed. The gain of the TIA is adjusted until a determination is made that a satisfactory or optimum link BER has been achieved.

Method and apparatus for adjusting the gain of an amplifier of an optical receiver module based on link bit error rate (BER) measurements

An FFE/DFE equalizer is provided that uses unclocked FIR filters. At least one of the unclocked FIR filters has tunable delay cells that can be tuned to adjust their respective time delay time periods. Because the FIR filters of the FFE/DFE equalizer are unclocked, the complexity and die area associated with clocking circuits are avoided, thereby enabling costs to be reduced. Because the delay cells of at least one of the FIR filters are tunable to enable their respective time delay periods to be adjusted, very good equalizer performance is achieved without having to use clocked circuits. In addition, because clocked circuits are not used in the FIR filters, the need for clocking circuits to control the timing of clocked circuits is obviated, which leads to a reduction in the amount of power consumed by the FFE/DFE equalizer.

Equalizer and method for performing equalization

A signal transmission system in accordance with the invention is implemented using a dual-purpose pin of an optical sub-assembly. The dual-purpose pin is used to propagate an analog signal out of the optical sub-assembly and also for providing an access point where an external element may be coupled to the optical sub-assembly for modulating the analog signal. The optical sub-assembly houses a photodetector, a signal transmitter circuit, and a signal receiver circuit. The photodetector receives light and generates a corresponding electrical signal indicative of the light intensity. The signal transmitter circuit converts the electrical signal received from the photodetector into the analog signal that is transmitted out of the dual-purpose pin. The signal receiver circuit located inside the optical sub-assembly is configured to monitor the modulated analog signal from the dual-purpose pin and generate therefrom, a control signal inside the optical sub-assembly.

Bi-directional signal transmission system using a dual-purpose pin

A semi-open feedback loop optical output power control apparatus and method are provided for use in an optical TX. The apparatus and method enable input data signals having content frequencies that are below the cutoff frequency of the optical output power monitoring and control feedback loop to be utilized. This is accomplished at least in part by opening and closing (i.e., is disabling and enabling) the feedback loop based on whether or not one or more transitions in the input data signal to the optical TX from a logic 0 to a logic 1, or vice versa, are detected within a predetermined timing interval. In addition, the apparatus and method provide these and other advantages without causing the optical TX to have an increased link startup settling time period. The feedback loop has a low pass filter (LPF) that has a selectable bandwidth. The bandwidth of the LPF is set to a high bandwidth at startup to enable shorter link startup settling time periods to be achieved by the TX and is set to a low bandwidth at a later time to enable the feedback loop to cause more accurate adjustments to the optical output power of the laser to achieve a better bit error rate (BER).

Apparatus and method for controlling the optical output power of a laser in an optical transmitter (TX)

Methods and apparatuses are provided for performing jitter measurements in a transceiver module. Accordingly, there is no need to use expensive test equipment that must be inserted into and removed from the network in order to obtain these measurements. In addition, because the measurements can be obtained at any time without any interruption in communications over the network, jitter performance can be monitored more closely and more frequently to facilitate better and earlier diagnosis of problems that can lead to failures in the network.

Methods and apparatuses for measuring jitter in a transceiver module

Laser modulation is controlled by using a measurement of the average output power level of the laser to adjust the amplitude of the modulation current as necessary to prevent the laser from being over- or under-modulated and to adjust the amplitude of the bias current as necessary to maintain the average output power level of the laser at a desired, reasonably constant level. The laser controller receives an electrical feedback signal from a laser output power monitoring device and uses this signal to obtain the measurement of the average output power level of the laser. Based on this measurement, a bias current control signal and a modulation current control signal are generated and output to the laser driver to cause the laser driver to set the amplitude of the bias current to achieve a desired average output power level and to set the amplitude of the modulation current to prevent over- and under-modulation.

Method and apparatus for controlling laser modulation based on measurements of average laser output power

The invention is directed to an OSA having a TO-can-type configuration that is relatively low-cost to manufacture and that has functionality for monitoring and controlling the temperature of the laser diode without the need for additional pins or an increase in the size of the OSA. Thus, the OSA typically includes four or five pins at most. These features of the invention are achieved by providing a thermal control circuit, a temperature sensor and a heater that are integrated along with a laser output power monitor photodiode into the submount assembly substrate.

Small form factor transmitter optical subassembly (TOSA) having functionality for controlling the temperature, and methods of making and using the TOSA

High-speed measurements of the output power level of a laser are obtained by using a high-speed laser output power monitoring device that is capable of producing an electrical feedback signal having an amplitude that varies as the output power level of the laser varies. A high-speed amplitude detector receives the electrical feedback signal and detects the amplitude of the feedback signal and produces an optical modulation amplitude (OMA) detection signal. The OMA detection signal is received in a high-speed amplitude measurement device that measures the OMA and produces an OMA measurement value. The OMA measurement value is then processed by the laser controller to obtain a modulation current control signal, which is then output to the laser driver to cause the laser driver to adjust the laser modulation current to obtain a desired or optimum laser output power level. An average amplitude measurement value may also be obtained using an average amplitude measurement device that processes the OMA detection signal produced by the high-speed amplitude detector to obtain the average amplitude measurement value. The laser controller receives the average amplitude measurement value and processes it to obtain a bias current control signal, which is then output to the laser driver to cause it to adjust the amplitude of the bias current to obtain a desired or optimum average laser output power level.

Method and apparatus for controlling output power levels of a laser used for optical data transmission based on data rate-speed optical feedback

A method for determining a condition of the laser system includes determining a change in a laser current from an initial value. A method for measuring a laser current includes determining a difference between the values of a power supply current, which is the value of the laser current. A method for measuring a transmitted power includes generating a first control signal that sets a magnitude of a bias current supplied to a laser, generating a second control signal that sets a of a modulation current supplied to the laser, and determining a difference between values of a high and a low transmitted powers. A method for measuring a received optical power includes determining a received OMA corresponding to the power signal, which is the transmitted OMA minus a known loss through a calibration fiber that couples the laser transmitter to the laser receiver.

Calibration of laser systems

A communication module includes a switch circuit operable to connect an internal bus to an external bus for, e.g., diagnostics, verification, and fault analysis. The internal bus allows data communication between electronic components internal to the communication module, and the external bus allows data communication between at least one internal electronic component and a device external to the communication module. The switch circuit may be controlled via a programmable and password protected register within the communication module.

Switch for coupling one bus to another bus

A circuit for disabling an energy-generating component. The circuit comprises an input operable to receive a disable signal and a disable circuit operable to disable the component in response to the disable signal for a predetermined duration of time sufficient to maintain an average power generated by the component at or below a predetermined level. The disable circuit further comprises a signal-detection circuit operable to detect the presence of disable signals having a respective rising edge and falling edge, a mask-signal generating circuit coupled to the signal detection circuit and operable to generate a mask signal when one of the edges of a first disable signal is detected; and a latching circuit coupled to the mask-signal generating circuit and operable to generate a mask disable signal if the mask signal is being generated and the other edge of a subsequent disable signal is detected.

Growing community of inventors

Santa Clara, CA, United States of America

Frederick W Miller