Abstract: An optical transmitter for a WDM (Wavelength Division Multiplexing) passive optical network (PON) and a WDM PON comprising such an optical transmitter are disclosed. An optical transmitter comprises first mirror and second mirrors at first end and second ends of a cavity; an optical amplifier positioned within the cavity upstream from the first mirror and for amplifying light polarized in a first polarization plane; an optical waveguide for transmitting light from the optical amplifier to the second mirror and vice versa; a first non-reciprocal polarization rotator upstream of the optical amplifier and downstream of the optical waveguide; and a second non-reciprocal polarization rotator upstream of the optical waveguide and downstream of the first mirror; wherein the first and second non-reciprocal polarization rotators rotate the polarization of the light such that light which re-enters the optical amplifier after having been reflected by the second mirror is polarized in the first polarization plane.

Abstract: An arrangement for connecting an electronic subassembly and an optical subassembly in an electro-optical communication device such as an electro-optical transceiver. The arrangement includes a body of a rigid dielectric material for mounting e.g. on the optical subassembly. The body has electrically conductive pathways provided thereon and includes a shaped portion providing a socket-like formation. At least one electrical contact element is coupled with e.g. the electronic subassembly. The electrical contact element is pluggable into the socket-like formation of the body of rigid dielectric material and includes an elastic device adapted to elastically co-operate with the socket-like formation of the body of rigid dielectric material to retain the electrical contact element plugged in the socket-like formation to provide electrical contact with the electrically conductive pathways provide thereon, while permitting vibrational displacement of the electrical contact element within the socket-like formation.

Abstract: An arrangement for connecting an electronic subassembly and an optical subassembly in an electro-optical communication device such as an electro-optical transceiver. The arrangement includes a body of a rigid dielectric material for mounting e.g. on the optical subassembly. The body has electrically conductive pathways provided thereon and includes a shaped portion providing a socket-like formation. At least one electrical contact element is coupled with e.g. the electronic subassembly. The electrical contact element is pluggable into the socket-like formation of the body of rigid dielectric material and includes an elastic device adapted to elastically co-operate with the socket-like formation of the body of rigid dielectric material to retain the electrical contact element plugged in the socket-like formation to provide electrical contact with the electrically conductive pathways provide thereon, while permitting vibrational displacement of the electrical contact element within the socket-like formation.

Abstract: An integrated optics non linear coupler presents on a surface a first and a second waveguide (2, 3) coupled contradirectionally by means of a distributed feedback grating (10). The first waveguide (2) defines an input port (4) and a first output port (5) of the device (transmission output) and the second waveguide (3) defines a second output port (6) of the device (reflection output). By means of an optical control signal injected into the device together with an information signal, the device can be brought to conditions of non-linear operation, thus making the grating (10) switch from transmitting to reflecting behaviour or vice versa with respect to a given wavelength.

Abstract: The nonlinear optical element for extremely high bit rates comprises a plate made of semiconductor material, in which is there is realized a sequence of variously doped layers, which can be passed through, in operation, by one or more light radiations. The element comprises a sequence of structures which exhibit excitonic nonlinearities, and which are placed geometrically close to layers of larger sizes, which act as dilution/recombination tanks for the carriers eliminated by the nonlinear structures. The element allows realization of optical devices, such as memories, directional couplers, switches, etc., in which fast excitonic nonlinearity is very evident and in which carriers are eliminated in time intervals of 1 to 10 ps, so that the devices are able to function at extremely high bit rates. (FIG.

Abstract: An optical processing device for light radiation provides non-linear transfer functions in an optical guide. A coupled quantum well modulator is reverse biased by an adjustable dc voltage source through an impedance and light radiation to be processed is sent in parallel with the layers composing the modulator guiding zone. The coupled quantum well modulator has a multiplicity of layers including some which form a guide zone comprised of a sequence of alternating quantum wells and barrier layers. The light radiation to be processed passes parallel to the layers through this guiding zone.

Abstract: A coupled quantum well electro-optical modulator, whose semiconductor structure is composed of one or of a plurality of successions formed by two layers capable of forming quantum wells, of a barrier layer which separates the two layers and of an intrinsic layer which separates the succession from other possible successions, where in presence of an electric field the absorption threshold of the light radiation shifts towards shorter wavelengths.