Patent application number | Description | Published |
20080247430 | Laser wavelength stabilization - In a coarse wavelength division multiplexing (CWDM) optical transmission system, a distributed feedback (DFB) laser is tuned so that the peak reflection of the grating overlaps with the gain range of the DFB laser. The diffraction grating is tuned so that the peak is positioned on the long wavelength end of the gain spectrum at a selected temperature. The optical transmission system operates in an environment having a wide temperature range (i.e., about −40° C. to about 85° C.). Heat is applied to the laser and as the laser temperature increases, the gain range overtakes the grating peak. When the gain range and the grating peak overlap at increased laser temperature, laser output is improved. | 10-09-2008 |
20110211603 | Laser wavelength stabilization - In a coarse wavelength division multiplexing (CWDM) optical transmission system, a distributed feedback (DFB) laser is tuned so that the peak reflection of the grating overlaps with the gain range of the DFB laser. The diffraction grating is tuned so that the peak is positioned on the long wavelength end of the gain spectrum at a selected temperature. The optical transmission system operates in an environment having a wide temperature range (i.e., about −40° C. to about 85° C.). Heat is applied to the laser and as the laser temperature increases, the gain range overtakes the grating peak. When the gain range and the grating peak overlap at increased laser temperature, laser output is improved. | 09-01-2011 |
20130094802 | Differential Driver, Circuits and Devices Including the Same, and Method(s) of Manufacturing the Same - The present disclosure relates to a differential drive circuit. The differential drive circuit generally includes a differential driver, a first transmission line coupled to a first output node of the differential driver, and a second transmission line coupled to a second output node of the differential driver. A laser diode is coupled to the first and second transmission lines. The first and second transmission lines have different delays, lengths, or impedances. In some embodiments, the delay between the first transmission line and the second transmission line is 0.2-0.4 times a rise time or fall time of a signal on either transmission line. | 04-18-2013 |
20130108280 | Data Signal Threshold Detection and/or Recovery in Optical and/or Optoelectronic Receivers and/or Transceivers | 05-02-2013 |
20130148680 | Circuit and Method for Limiting Current to Prevent Roll-Over in Laser Diodes - The present disclosure relates to an optical power monitoring circuit including an automatic power control (APC) loop and a microcontroller unit (MCU), and a method for monitoring the same. The APC loop comprises a laser diode (LD) and a feedback loop to maintain a laser optical power. The MCU is configured to (i) monitor a bias current using a current sense circuit, (ii) monitor a rate of change of the bias current with time, and (iii) adjust a target power of the APC loop. By monitoring the bias current and the rate of change, and comparing them against thresholds, the target power can be adjusted by the MCU, to prevent roll-over in the laser diode, damage to the laser, and/or a hard failure in the data links that use the laser. | 06-13-2013 |
20130251361 | Enhanced Status Monitoring, Storage and Reporting for Optical Transceivers - An optical transceiver and methods for using the same are disclosed. The optical transceiver and methods may be useful for providing more accurate information regarding trends in operation of the optical transceiver, predicting an impending failure of the optical transceiver, and providing details of the optical transceiver prior to failure. The optical transceiver generally includes (1) at least one of (i) a receiver configured to receive optical information and (ii) a transmitter configured to transmit optical information, (2) circuitry configured to sample data for one or more operational parameters of the receiver and/or transmitter, (3) logic configured to perform one or more statistical calculations on the sampled data to generate statistical information, and (iv) one or more memories configured to store the sampled data and the statistical information. | 09-26-2013 |
20130287392 | Circuits and Methods for Monitoring Power Parameters in an Optical Transceiver - A circuit, optical transceiver and/or methods for using the same may be useful for determining average power, extinction ratio, and/or modulation amplitude when monitoring an optical transceiver and/or optical network. The circuit generally comprises a photodiode configured to generate a first current responsive to an optical signal, a current mirror coupled to a first terminal of the photodiode, and a detector coupled to a second terminal of the photodiode. The current mirror is configured to produce a second current equal to or proportional to the first current, and the detector is configured to determine a power or amplitude of the optical signal. Further, the present scheme may communicate information using a low speed signal superimposed on or combined with the relatively high speed optical signal. | 10-31-2013 |
20130336650 | Enhanced Received Signal Power Indicators for Optical Receivers and Transceivers, and Methods of Making and Using the Same - An optical transceiver and/or optical network, and methods of monitoring optical transceivers, may be useful for increasing the dynamic range and/or determining the received signal strength and/or link budget of the optical transceiver and/or a different optical transceiver in the optical network. The circuitry generally comprises a photodiode configured to generate a first current responsive to an optical signal, a current mirror configured to produce a second current equal or proportional to the first current, and a nonlinear element configured to produce a first voltage from the first current. | 12-19-2013 |
20140105610 | Power-Saving Driver Circuit for Providing a Bias Current or Driving a Current-Driven Load - Methods and circuits for providing a minimum driving voltage to a current-driven load (such as a laser diode) are disclosed. The circuit and methods may be useful for efficiently providing a bias and/or driving current to the current-driven load with minimal energy loss. The circuit generally comprises (1) a driver or voltage source configured to provide the bias and/or driving current to the current-driven load, (2) a sense circuit configured to (i) sense the bias and/or driving current and (ii) convert the bias and/or driving current to a first voltage, and (3) a comparator configured to (i) receive the first voltage and first and second reference voltages and (ii) provide a feedback/error signal to the driver or voltage source, the feedback/error signal configured to maintain or adjust the bias and/or driving current at or towards a target value. | 04-17-2014 |
Patent application number | Description | Published |
20120004803 | METHOD AND DEVICE FOR OPERATING AN INTERNAL COMBUSTION ENGINE - A method and a device operate an internal combustion engine having a plurality of cylinders with which are associated respective injection valves for metering fuel, and having an exhaust gas probe which is arranged in an exhaust gas tract and the measurement signal of which is characteristic of the air/fuel ratio in the respective cylinder, and having a crankshaft angle sensor the measurement signal of which is representative of a crankshaft angle of the crankshaft. Within a predefined operating range of the internal combustion engine, and when at least one predefined condition is fulfilled, a rough-running based cylinder-individual diagnosis (CYBL-HOM) with regard to harmful emissions is carried out before activation of a cylinder-individual lambda control (CILC) is enabled. | 01-05-2012 |
20120006107 | DEVICE FOR OPERATING AN INTERNAL COMBUSTION ENGINE - An association unit is designed to determine cylinder-individual lambda signals on the basis of a lambda probe signal and to determine lambda deviation signals for the respective cylinders based on the lambda signals in relation to an averaged lambda signal. Furthermore, an observer has a sensor model of the lambda probe that is arranged in a feedback branch. The lambda deviation signals are fed to the input side and observer output quantities in relation to the respective cylinder are representative of the injection characteristics deviations from predetermined injection characteristics. A parameter detection unit impresses a predetermined interference pattern from cylinder-individual mixture deviations. It further changes at least one sensor model parameter as a detection parameter in response to the respectively predetermined interference pattern for as long as the observer output quantities represent the portion of the interference pattern associated with the cylinders thereof in a predetermined manner. | 01-12-2012 |
20140014081 | Diagnosis Method And Device For Operating An Internal Combustion Engine - A method is disclosed for performing an individual cylinder diagnosis with respect to pollutant emissions within a predefined operating range of an internal combustion engine, meeting at least one predefined condition. During the performing of the individual cylinder diagnosis, a forced activation, by means of which a predefined air/fuel ratio to be set is activated, is prescribed in a manner synchronous to the cylinder segment. The excitation is carried out such that each individual cylinder is subjected during subsequent working cycles to a mixture that is either richer or leaner in comparison to the predefined air/fuel ratio to be set due to the forced excitation. Depending on the forcibly activated air/fuel ratio to be set, the corresponding injection valves are actuated. | 01-16-2014 |