Abstract: An edge-emitting etched-facet optical semiconductor structure includes a substrate, an active multiple quantum well (MQW) region formed on the substrate, a ridge waveguide formed over the MQW region extending in substantially a longitudinal direction between a waveguide first etched end facet disposed in a first window and a waveguide second etched end facet disposed in a second window, and first and second trenches having non-uniform widths extending in substantially the longitudinal direction between the first and second windows.

Abstract: An N-channel parallel optical transmitter includes a dual-facet continuous-wave laser, two or more optical splitters, and four or more optical modulators. One of the optical splitters has an input coupled to the first facet of the laser, and another has an input coupled to the second facet of the laser. The outputs of the splitters are coupled to the inputs of the optical modulators.

Abstract: An edge-emitting optical semiconductor structure has a substrate, an active multiple quantum well (MQW) region formed on the substrate, and a ridge waveguide extending between first and second etched end facets. The first etched end facet is disposed in a first window, while the second etched end facet is disposed in a second window. The first etched end facet extends between a pair of alcoves in the first window, and the second etched end facet extends between a pair of alcoves in the second window. An integrated device in which two such structures are provided has an H-shaped window where the two structures adjoin each other. The structure can be fabricated using a process that involves a first mask to form the ridge waveguide and then a second mask and an etching process to form the windows.

Abstract: An edge-emitting etched-facet optical semiconductor structure has a substrate, an active multiple quantum well (MQW) region formed on the substrate, and a ridge waveguide formed over the MQW region extending in substantially a longitudinal direction between a waveguide first etched end facet and a waveguide second etched end facet. A mask layer used to form windows in which the etched end facets are disposed consists of a single dielectric material disposed directly on the ridge waveguide. An optical coating consisting of no more than one layer of the same dielectric material of which the second mask is made is disposed directly on the second mask and disposed directly on the windows to coat the etched end facets.

Abstract: There is provided an opto-electronic communication system. The opto-electronic communication system has (a) a transmitter module including an electro-optical source for converting an electrical input signal into an optical output signal, (b) a receiver module including an opto-electrical detector for converting an optical input signal into an electrical output signal, (c) a sensor for sensing a bit rate of the optical input signal, (d) an adaptation unit associated with the transmitter module for varying an operation parameter of the transmitter module, and (e) a processing unit for determining a desired operating parameter of the transmitter module based on the bit rate, and for controlling operation of the adaptation unit in order to adapt operation of the transmitter module in accordance with the desired operating parameter.

Abstract: A transmitter optical sub assembly includes a laser source having associated therewith a laser driver and a package for housing the laser source (10) and the laser driver. The package includes respective separate compartments for the laser source and the laser driver, wherein a package wall, which is opaque to IR emission, separates the laser source from the laser driver. The laser source and the laser driver are arranged in those separate compartments whereby the laser source is exempt from being directly irradiated by the laser driver.

Abstract: A method for evaluating the aging level of a component includes measuring values of the elapsed time in operation of the component (tm,i), at least one entity (Im,i) indicative of the aging of the component, and the temperature (Tm,i) of the component, and processing the values measured as a function of a reference temperature (Tref) to produce corresponding normalized reference values (tref,i; Im,i) representative of virtual operation of the component at said reference temperature (Tref). An updated prediction model for the at least one entity over time is generated from the reference values (tref,i; Im,i). A predicted value (Ifit) for the at least one entity at a given time obtained by means of the prediction model is compared with an aging threshold. An aging warning signal is generated if the comparison indicates deviation of the predicted value (Ifit) beyond an acceptable range.

Abstract: A suite of optical performance monitoring (OPM) methods, based on optical subcarrier multiplexing, are described by the invention. The strength of this approach lies in the simplicity of double sideband subcarrier signals and the fact that these signals travel the complete optical path with the baseband signal of interest. The subcarrier signals can be recovered using techniques described in the application and are immune to fiber dispersion induced fading.

Abstract: An opto-electronic communication system includes at least one of a transmitter module including an electro-optical source such as a laser for converting an electrical input signal (IS) into an optical output signal (OS), and a receiver module including an opto-electrical detector for converting an optical input signal (OS?) into an electrical output signal (IS?). The system also includes at least one adaptation unit configured for varying at least one operation parameter of the transmitter module and/or receiver module. A processing unit such as a microcontroller is provided for controlling operation of the one adaptation unit in order to adapt operation of the transmitter module and/or receiver module to different operation conditions such as different communication standards.

Abstract: The aging level of a component, such as a laser (24) in an optical communication system, is evaluated by performing at repeated instants of time (i) during the useful life of the component (24), the steps of: measuring values of the elapsed time in operation of the component (tm,i), at least one entity (Im,i) indicative of the aging of the component (24), and the temperature (Tm,i) of the component, processing the values measured as a function of a reference temperature (Tref) to produce corresponding normalized reference values (tref,i; Im,i) representative of virtual operation of the component at said reference temperature (Tref). Starting from the reference values (tref,i; Im,i) thus produced, an updated prediction model for said at least one entity over time is generated. A predicted value (Ifit) for said at least one entity at a given time obtained by means of the prediction model is compared with an aging threshold.

Abstract: A transmitter optical sub assembly includes a laser source (10) having associated therewith a laser driver (18) and a package (24) for housing the laser source (10) and the laser driver (18). The package includes respective separate compartments (26, 30) for the laser source (10) and the laser driver (18), wherein a package wall, which is opaque to IR emission, separates the laser source (10) from the laser driver (18). The laser source (10) and the laser driver (18) are arranged in those separate compartments (26, 30) whereby the laser source (10) is exempt from being directly irradiated by the laser driver (18).

Abstract: A suite of optical performance monitoring (OPM) methods, based on optical subcarrier multiplexing, are described by the invention. The strength of this approach lies in the simplicity of double sideband subcarrier signals and the fact that these signals travel the complete optical path with the baseband signal of interest. The subcarrier signals can be recovered using techniques described in the application and are immune to fiber dispersion induced fading.