Abstract:
A method for forming a substantially flat planar lightwave optical circuit which has a substantially flat planar silica substrate and a sintered glassy lightguiding layer over the silica substrate. The structure is given a post treatment at an elevated temperature for a time sufficient to flatten said structure and compensate for distortion. Alternatively, the silica substrate may be heated and presagged to a predetermined degree to compensate for distortion or warpage which will occur in later processing.
Abstract:
A coupler is provided having waveguides which are arranged in two symmetrical groups in relation to the axis ¢X! of the coupler and consist of waveguide branches that are connected in a tree-like manner by n levels of Yjunctions, with at least the two output ports ¢S1! ¢S32! that are located farthest from the axis ¢X! of the coupler being fed by waveguides that have no singularities and that, between the first and the nth junction level of junctions, further consist of points of inflection located outside the junctions. The two junctions ¢44! ¢45! in the (n - 1)th level of the junctions that are located closest to the axis ¢X! of the coupler have axes of symmetry ¢X1! ¢X2! that are parallel to the axis of symmetry of the coupler, with the axis of each of these junctions defining an axis of symmetry for two junctions ¢57! ¢58! and ¢59! ¢510! in the nth junction level that are likewise parallel to the axis of the coupler, and also for the four output ports ¢S13! to ¢S16! and ¢S17! to ¢S20! that they feed.
Abstract:
The demultiplexer comprises: a) an inlet wave-guide (1); b) a plurality of outlet wave-guides (5i); c) an assembly (3) of adjacent integrated wave-guides functioning in the form of a phase network; d) a mode-expanding wave-guide (12) arranged at the inlet of the inlet connector (2) and connected to the inlet wave-guides (1); and e) a plurality of mode-reducing wave-guides (16i) arranged at the outlet of the outlet connector (4) and connected in each case to one of the outlet wave-guides (5i). The mode-expanding guide (12) and the aforementioned mode-reducing guides (16i) are of identical geometry with a width that varies linearly in accordance with their length, whereby the width of the aforementioned expanding and reducing guides at their connection to the associated connector is defined in order to optimize the width of the band passing through a channel while limiting the cross-talk between the outlet channels (5i) to a pre-determined level.