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AssigneePacific Fiberoptics, Inc.
InventorsJeffrey V. King, William I. Fletcher, Leon M. Lemon, David D. Olsen
Estimating the term…
Intelligent fiberoptic/laser diode transmitter/controller modules and methods of operating and manufacturing the same are disclosed. During calibration procedures for the modules, a laser diode is characterized over a defined operating temperature range. Characteristic data and/or curves defining the operational characteristics of the laser diode over the range of operating conditions (temperature, power supply) are stored in non-volatile memory such as EEPROM. During operation, an embedded microcontroller together with analog to digital converters, digital to analog converters and other associated circuitry, dynamically control the operational parameters (e.g. modulation and bias current) based on the current operating conditions (temperature, power supply). The operating conditions are used as an index into the non-volatile memory containing operational data tables as well as predicted "end-of-life" data. An automatic power control loop and data compensation scheme maintain constant optical output power over the entire operating range. The microcontroller continually updates the operating control parameters of the laser diode based on the currently sensed operating conditions. The microcontroller also continually monitors for alarm conditions such as (a) optical power-out of range (b) laser end-of-life condition. The microcontroller also gathers statistical information such as hours of operation, most extreme operating conditions, conditions at time of alarm event and number of alarm events that have occurred. Such information is stored in non-volatile memory. In addition, a serial interface to the microcontroller provides a programming and monitoring channel for pre-installation calibration and "in-the-field" monitoring and control and provides the flexibility to monitor and/or change various parameters. The serial interface provides the channel to program the device during calibration. It also provides the flexibility (if the application requires) to monitor and change parameters in operational use without taking the laser diode transmitter off-line. If desired, the optical power out of range alarm thresholds, the laser end-of-life criteria, the bias and modulation currents, the optical output power, status and control information may be dynamically monitored and/or changed without taking the laser diode transmitter off-line.
A fiberoptic transmitter, comprising:
A method of calibrating a fiberoptic transmitter, the transmitter including a laser diode emitting optical energy and a biasing circuit for applying bias to the laser diode, the bias circuit including first and second control loops, the first control loop, under processor control, supplying during normal operation of the transmitter an amount of modulation current to the laser diode responsive to data retrieved by the processor froma a memory, the retrieved data having been stored in the memory during a previous calibration of the transmitter and depending upon a currently sensed operating condition of the laser diode, the second control loop providing bias current to the laser diode in an amount to maintain the optic energy emitted from the laser diode at a predetermined average level, the method comprising, for each particular value in a set of values for the operating condition, the steps of:
Dependencies are inferred from the claim text.