Optical transmitter using overlapping mode spectra - sub-divides interferometric branched Y=shaped waveguide laser into sections, with separate current paths providing individually-controllable current to associated segments for changing optical length of resonator

摘要

A controller (ST) supplies a laser with current. The laser is an interferometric Y-shaped laser (Y) divided into several individually controllable segments. The lengths of the coupled resonator sections are chosen so that the stimulated resonator modes for a fixed applied current have approximately equal separating distances. From the controller, at least two current paths (P1,P2) related to different resonator segments (3,4;1,4) of the laser are connected and carry currents which can be different. The current paths are connected via segments in different arms of the laser. USE/ADVANTAGE - Enables coherence length and line width of transmitted light to be adjustable over wide range so that it can even be used where light of short coherence length is required. Enables wide coherence length variability by switching current paths. Line width is adjustable over 10 MHz to 2 Thz. Spectrum resembles that of LED. Individual modes can be superimposed to Supermode.