In another attempt, laser controllers have been employed that include pre-set laser current or power compensation tables based on digital measurement. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. by operating on the active mediumStabilisation of laser output parameters by monitoring the optical output parametersTransmission systems employing electromagnetic waves other than radio-waves, e.g. Such light sources, including for example a laser diode positioned in a transmitter optical subassembly of an optical transceiver module, should conform to pre-defined parameters propounded by the manufacturer or applicable industry. • The highest solar laser collection efficiency of 32.5 W/m 2 was attained, under 870 W/m 2 solar irradiance.. A novel fused silica liquid light … ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NELSON, STEPHEN T.;REEL/FRAME:023521/0335NOTICE OF GRANT OF SECURITY INTEREST IN PATENTS;ASSIGNORS:II-VI INCORPORATED;MARLOW INDUSTRIES, INC.;EPIWORKS, INC.;AND OTHERS;REEL/FRAME:050484/0204BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT, NORTH CAROLINANOTICE OF GRANT OF SECURITY INTEREST IN PATENTS;ASSIGNORS:II-VI INCORPORATED;MARLOW INDUSTRIES, INC.;EPIWORKS, INC.;AND OTHERS;REEL/FRAME:050484/0204ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FINISAR CORPORATION;REEL/FRAME:052286/0001
In one embodiment, a method for setting a modulation current for the laser of an optical transmitter is disclosed wherein data relating to the laser transmit power and laser bias current at a plurality of laser bias current levels are sensed. For or Z instance, as has been mentioned LSE can be affected by laser temperature fluctuations, as well as by time-based changes that occur over the operational lifetime of the laser. This relationship is depicted in the following equation:In accordance with one embodiment, therefore, a method is followed to enable dynamic determination of and compensation for LSE of a laser, such as the laser The storage of laser slope efficiency data can be useful for several reasons, among them, benchmarking purposes for future calculations, determining prior settings when the transceiver is powered on after a period of shut-off, or for estimation purposes when time does not allow for a full laser slope efficiency calculation to be made.
Slope efficiency, also known as SE, is simply the slope of the laser's output power versus drive current curve. Diagnostic data can be provided in analog or digital form. sensing data relating to laser transmit power and laser bias current at a plurality of laser bias current levels;by a processor, calculating a slope efficiency of the laser using the data by comparing a ratio of bias current to transmit power data for a plurality of bias current levels of the laser;by the processor, determining a desired modulation current for the laser using the slope efficiency; andif needed, modifying the modulation current of the laser to match the desired modulation current.acquiring data relating to the laser transmit power at both a laser bias current level that is greater than an average light level bias current and a laser bias current level that is less than the average light level bias current.sensing the laser transmit power by a photodiode positioned in relation to the laser; andsensing the laser bias current by a resistor placed in series with a laser bias current signal line.at least temporarily storing the data in a memory that is accessible by the processor.calculating the laser transmit power corresponding to at least one of a logic â1â and a logic â0â power level.17. Information regarding ER and OMA determination could then be provided to the Host, or stored in non-volatile memory for other purposes.Again, and as mentioned above, should communication with the external host In addition, compensation for LSE as described herein enables estimation of remaining lifetime of the laser, thereby allowing changeout of the transceiver at a prudent time before failure of the laser occurs.
Examples of operating parameters for a laser include its average light level, extinction ratio, and optical modulation amplitude.Known attempts for compensating for laser characteristics dependent upon temperature have involved the use of temperature-sensitive analog components to alert for the need to adjust laser current during operation, which in turn desirably affects laser temperature. One of these factors is laser temperature. The slope efficiency is the slope of this line. In this letter, we demonstrate high slope efficiency laser emission from reflective liquid crystal laser devices with a silicon backplane.
All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.Systems and methods are provided for determining and compensating for the laser slope efficiency of a light source positioned in an optical transmitter in order to properly set a modulation current for the light source. In the latter case, detection of an ambient temperature fluctuation can be forwarded to the controller, which consults the pre-set compensation table and instructs the laser controls to be modified accordingly. The environmental parameter may be, for example, supply voltage, humidity, acceleration, ambient light levels, ambient vibration, magnetic flux intensity, ambient interior transceiver temperature, or any other environmental parameter that may affect the performance of an optoelectronic device and that may be compensated for by suitable adjustment of one or more operational parameters. This calculator gives the amplification efficiency of a qPCR reaction based on the slope of the standard curve. Among the disadvantages is the fact that the compensation table used by the controller must be predefined during optical transmitter manufacture, and as such, is not capable of dynamic laser modification according to present operating requirements. These parameters, which indicate whether the optical signal is adequate for data transmission purposes are defined by the particular physical transmissive interface, i.e., Fibre Channel, gigabit ethernet, Sonet, etc.Various factors can affect the operating parameters of a laser diode during its optical transmission activities, which can correspondingly cause the laser to exceed acceptable ranges for such parameters.