Intelligent fiberoptic transmitters and methods of operating and

Abstract

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.