Abstract: A multiwavelength transmitter comprises several laser sources (1) each configured to generate light of a different wavelength and a first array waveguide grating (2) arranged to direct light from each of the laser sources (1) into a first waveguide. The transmitter further comprises several electroabsorption modulators (7) each arranged to modulate light at one of the wavelengths with a respective data signal and a second array waveguide grating (6) arranged to direct each of said different wavelengths of light from the first waveguide to a respective one of the modulators (7). The optical modulators (7) are reflective optical modulators and the second array waveguide grating (6) is arranged to direct the modulated light reflected from each of the optical modulators (7) back into the first waveguide. An optical circulator (5) is provided in the first waveguide to couple modulated light from the second array waveguide grating (6) into an output waveguide.

Abstract: A multiwavelength transmitter comprises several laser sources (1) each configured to generate light of a different wavelength and a first array waveguide grating (2) arranged to direct light from each of the laser sources (1) into a first waveguide. The transmitter further comprises several electroabsorption modulators (7) each arranged to modulate light at one of the wavelengths with a respective data signal and a second array waveguide grating (6) arranged to direct each of said different wavelengths of light from the first waveguide to a respective one of the modulators (7). The optical modulators (7) are reflective optical modulators and the second array waveguide grating (6) is arranged to direct the modulated light reflected from each of the optical modulators (7) back into the first waveguide. An optical circulator (5) is provided in the first waveguide to couple modulated light from the second array waveguide grating (6) into an output waveguide.

Abstract: A connector assembly for connecting and aligning an active optical component with an optical waveguide is provided. The assembly comprises: (i) a waveguide chip having an optical waveguide embedded beneath a cladding layer and a cavity for accommodating the active optical component comprising at least one wall extending from the surface of the cladding layer through the waveguide; and (ii) a second chip for carrying the active optical component. The waveguide chip comprises a locating stop and the second chip has first and second reference regions formed thereon, the first reference region being adapted to locate the active optical component, and the second reference region being adapted to engage the surface of the cladding layer and the locating stop of the waveguide chip when the waveguide chip and second chip are connected together with the active optical component located within the cavity in order to provide alignment of the waveguide with the active optical component.

Abstract: A method of producing a planar waveguiding device having a core [10] and a cladding [17]. The cladding has groves [11,12] directly interfacing [15,16] with the core [10]. A layer of core glass [10] is deposited on the surface of a substrate [23,24]. This layer is etched to produce a shaped layer which includes a first core portion [10] having the same configuration as the intended core [10] and an expanded core portion [30] wherein the core glass extends beyond the intended core boundary. A glass covering layer [21] is deposited over the etched core glass and grooves [11,12] are produced by etching through the covering layer [21] and into said expanded core portion [30].

Abstract: A planar waveguiding device includes at least on section of core which is located between and adjacent to two grooves. The refractive index within the grooves is substantially equal to one and the grooves are located so that the evanescent fields of optical signals travelling in the core extend into the grooves. Preferably the grooves have a direct interface with the core and they extend through a layer located above the core into a layer located below the core. Where the cores have bends, e.g. bends with radii of curvature below 2 mm the grooves are located both inside and outside the bends.

Abstract: An arrayed waveguide grating [WDG] comprises I/O slabs (53a, 53b) interconnected by a grating region (51). The grating region (51) comprises many, e.g. at least 25 and preferably 50 to 500, individual cores (61,62,63), which have different lengths so as to provide wavelength selectivity by causing phase changes in light conveyed between the I/O slabs (53a, 53b). There are bends (64) for providing the different lengths and, to improve optical guidance round the bends, empty (R.I.=1) grooves (71) are located adjacent to the inside (71.1) and outside radii (71.2) so that the evanescent fields extend into the grooves (71). In order to keep the dimensions small, which improves the optical accuracy, tight bends (preferred radii of curvature of less than 2 mm and especially less than 500 &mgr;m) are desirable. The grooves conveniently have tapered ends and they extend into straight portions adjacent to the bends.

Abstract: A connector assembly for connecting and aligning an active optical component with an optical waveguide is provided.

Abstract: It has been demonstrated that B containing glasses are sensitive to radiation in the band 225-275 nm and, therefore, B2O3 glasses are particularly adapted to receive refractive index modulation, e.g., to make reflection gratings. Glasses containing SiO2 and B2O3 are particularly suitable when the grating is to be localized in the cladding of a fiber. Glasses containing SiO2, GeO2, and B2O3 are suitable when the grating is in the path region of a waveguide, e.g., in the core of a fiber.

Abstract: An optical device includes a waveguiding configuration and an electrical capacitive configuration. The capacitive configuration includes glass electrode region(s) and glass dielectric region(s) with electrical leads, e.g., metallic conductors, for applying electrical control signals to the electrode region(s). The preferred metals for the conductors are Ni, Ti and Au. The waveguiding structure is configured so that the fields associated with optical signals propagating therein interact with dielectric region(s). During the use of the device control signals are applied to the dielectric region(s) by the electrical leads. The control signals have the effect that temporary electric fields are applied to the dielectric region(s). The fields change the optical properties of the dielectric region(s) and this affects the propagation of the optical signals. The device can either be produced in planar or fibre configurations.

Abstract: Boron containing glasses are sensitive to radiation in the band 225-275 nm and therefore, B.sub.2 O.sub.3 glasses are particularly adapted to receive refractive index modulation, e.g., to make reflection gratings. Glasses containing SiO.sub.2 and B.sub.2 O.sub.3 are particularly suitable when the grating is to be localized in the cladding of a fibre. Glasses containing SiO.sub.2, GeO.sub.2 and B.sub.2 O.sub.3 are suitable when the grating is in the path region of a waveguide, e.g., in the core of a fibre.

Abstract: It has been demonstrated that B containing glasses are sensitive to radiation in the band 225-275 nm and, therefore, B.sub.2 O.sub.3 glasses are particularly adapted to receive refractive index modulation, e.g., to make reflection gratings. Glasses containing SiO.sub.2 and B.sub.2 O.sub.3 are particularly suitable when the grating is to be localized in the cladding of a fiber. Glasses containing SiO.sub.2, GeO.sub.2, and B.sub.2 O.sub.3 are suitable when the grating is in the path region of a waveguide, e.g., in the core of a fiber.

Abstract: A planar waveguiding device has the cores of fibre tails directly connected to the path regions of the waveguiding structure. The devices are produced by attaching the fibre tails before the path layer is deposited. The direct connections are produced when the path layer is sintered.

Abstract: A planar waveguiding device has the cores of the fibre tails directly connected to the path regions of the waveguiding structure. The devices are produced by attaching the fibre tails before the path layer is deposited. The direct connections are produced when the path layer is sintered.