Novel Embodiment of a Multisection Semiconductor laser for use as a wavelength tunable transmitter with channel location and locking.

摘要

A novel hybrid, silicon waveguide device with associated method to calibrate, identify wavelength and lock a multi-section semiconductor laser for use as a wavelength tuneable transmitter. The invention exploits to full advantage an embedded Bragg grating filter whose optical throughput or transmission varies in a known way with wavelength so that the throughput power is measured and this is used to compute wavelength in the described manner. Furthermore, a data input/output unit is used to increment currents, as required, to the laser and also to read back current from photo-detectors which is in turn a measure of the wavelength as modified by the filter in a known fashion. A Fabry Perot etalon slotted into the waveguide permits the laser to be locked the ITU plan for WDM optical networks. This means that a single data acquisition unit, or DAQ, with multiple input and output channels can be used to replace the host of electric current sourced and a wavelength meter or analyser, while avoiding the associated time-consuming delays. A microprocessor or ASIC may be used to replace the DAQ.