Abstract: Phosphate free, Er/Yb co-doped borosilicate glass compositions and optical devices made from said compositions are disclosed; said compositions comprising, for 100 parts by weight of: 60 to 70 parts by weight SiO2 or SiO2+GeO2 with SiO2 always being greater than 40 parts by weight, 8 to 12 parts by weight of B2O3, 10 to 25 parts by weight M2O wherein M2O is an alkali metal oxide, 0 to 3 parts by weight of BaO, 0.1 to 5 parts by weight Er2O3, and from 0.1 to 12 parts by weight of Yb2O3 and from 0 to less than 5 parts by weight F; and within which, the boron atoms are of tetrahedral spatial coordination.

Abstract: A structure for use in forming an optical component and a method of making such a component is described. The structure comprises a non-waveguiding body of optical material having a concentration of a photorefractive-sensitive component in the body such that upon irradiation of a part of the body by a beam of actinic radiation, the refractive index of the irradiated part is increased. The method of making the optical component comprises providing a non-waveguiding body of optical material; providing a concentration of a photorefractive-sensitive component in the body; contacting the non-waveguiding body of optical material with an atmosphere comprising one of hydrogen, deuterium and mixtures thereof; and exposing a part of the non-waveguiding body of optical material to actinic radiation such that the refractive index of the exposed part is increased. Such a structure and method can be used to form symmetrical planar waveguides, optical fiber waveguides and other optical components such as gratings.

Abstract: The device consists of a dual-mode waveguide 1 that has a longitudinal axis ?X!, a length ?L!, and a width ?W!, and two pairs of monomode waveguides 2, 3 and 4, 5, for entry and exit, respectively. In accordance with the invention, the length ?L! and the width ?W! of the dual-mode waveguide ?1! are selected in such a way as to establish, in this guide, light coupling that is greater in the window from 1260 to 1360 nm than in the window from 1480 to 1580 nm, so as to compensate for the significant contrary proximity coupling in these windows, as created between the monomode entry guides 2 and 3 on the one hand and the monomode exit guides 4 and 5 on the other hand.

Abstract: An integrated optical proximity coupler comprises first and second parallel straight interaction waveguide segments. First and second end segments are connected to the input ends of the first and second straight waveguide segments, respectively, by means including first and second curved segments, respectively. The end segments are both the same predetermined size which is determined by conventional optical fibers to which they are to be connected. To make the device broad banded, one of the straight segments must be narrower than the other. To reduce device excess loss, the first straight segment and at least part of its respective curved segment are made slightly narrower than the end segments, and the second straight segment and at least part of its respective curved segment are made slightly wider than the end segments. Thus, the required .DELTA..beta. can be obtained without making the narrow path too narrow.

Abstract: The invention comprises (a) a divider (D) by 2 of the optical power received at one input (E.sub.1, E.sub.2) and (b) two groups of single mode waveguides coplanar to the divider and symmetrical relative to the axis of symmetry (Z) of the divider (D), each group being composed of waveguide sections connected in tree and branch fashion by Y junctions (J.sub.ii) between one input junction (J.sub.11, J.sub.12) connected to one of the outputs of the divider and N sections of waveguide difining N outputs (S.sub.1 to S.sub.16) of the coupler parallel to the axis of the divider. According to the invention, each of these input junctions (J.sub.11, J.sub.12) has a rectilinear input branch (B.sub.1) with predetermined length such that the transverse distribution of the optical power at the output of the rectilinear input branch (B.sub.1) is centered to a large degree on the axis of this input branch.

Abstract: The present invention relates to a coupler having one input port and 2.sup.n output ports which includes a plurality of essentially coplanar waveguides connecting the input port to one of the 2.sup.n output ports. The plurality of waveguides are arranged in two symmetrical groups in relation to the axis of the coupler and have points of inflection. Each of the waveguides includes branches connected in a tree-like manner by n levels of Y-junctions where the waveguides connecting at least two of the output ports that are located furthest from the axis of the coupler to the input port have no singularities and between the first level and the nth level of the Y-junction have points of inflection located outside the junctions. Further, the junctions located along these waveguides have axes of symmetry which are not parallel to the axis of the coupler.

Abstract: A device, utilized for the separation or combination of two signals of different wavelengths, of the type in which the waveguides comprise straight interaction segments (1.sub.1, 2.sub.1 ; 1.sub.in, 2.sub.in) parallel and close to one another and to curved approach segments with inflection points (1.sub.2, 2.sub.2, 1.sub.3, 2.sub.3 ; 1.sub.2n, 2.sub.2n, 1.sub.3n, 2.sub.3n), connected to the ends of the straight segments, and, for certain ones, to inputs/outputs (4,5,6) of the device. In accordance with the invention, the approach segments situated on at least the same side of the straight segments are free of any inflection point, the coupling of the straight segments being optionally modified to compensate for the variation of the coupling between the waveguides along said approach segments due to the omission of the inflection points.

Abstract: A device, utilized for the separation or combination of two signals of different wavelengths, of the type in which the waveguides comprise straight interaction segments (1.sub.1, 2.sub.1 ; 1.sub.1n, 2.sub.1n) parallel and close to one another and to curved approach segments with inflection points (1.sub.2, 2.sub.2, 1.sub.3, 2.sub.3 ; 1.sub.2n, 2.sub.2n, 1.sub.3n, 2.sub.3n), connected to the ends of the straight segments, and, for certain ones, to inputs/outputs (4, 5, 6) of the device. In accordance with the invention, the approach segments situated on at least the same side of the straight segments are free of any inflection point, the coupling of the straight segments being optionally modified to compensate for the variation of the coupling between the waveguides along said approach segments due to the omission of the inflection points.

Abstract: A splitter is produced by ion diffusion in a glass substrate and it is designed to assure the transmission of an optical signal toward two outputs with a predetermined ratio of the signal power appearing at these 2 outputs. In accordance with the invention, it comprises an X-junction of two rectilinear waveguides defining at their intersection a half-angle .alpha., the angle and the geometry of the central region being chosen in such a way as to establish the predetermined power ratio and the relative achromaticity of the device.

Abstract: The coupler comprises two waveguides imbedded in a substrate and exhibiting a coupling region of length L establishing coupling coefficients (C.sub.1) and (C.sub.2) for the signals of the wavelengths (.lambda..sub.1) and (.lambda..sub.2) respectively. Following the invention, the length (L) and the coefficients (C.sub.1) and (C.sub.2) are linked by the relationship: ##EQU1## where n and m are integers, one uneven and the other even, chosen in such a manner as to establish a pass band of predetermined width (BP1, BP2) around at least one of the wavelengths (.lambda..sub.1) and (.lambda..sub.2). The invention has application to multiplexers/demultiplexers for optical fiber telecommunications.

Abstract: An optical signal amplifier with a waveguide path integrated into a glass body that is doped with optically active material. The signal to be amplified is transmitted through the waveguide and the pump power is coupled into the waveguide at one end. The waveguide comprises closely spaced adjacent guide lengths in the form of a spiral, zigzag paths between mirrors, or parallel paths with connecting semicircles at alternating ends of succeeding pairs of paths.