Abstract: A unique sensor is used to detect a transmission impairment that may have affected incoming optical channel signals. The sensor, more specifically, selects a group of the incoming channel signals and generates a first power signal, P0, over the selected group of signals and generates a second power signals, P1, over a weighted version of the selected group of channel signals. The sensor then generates, as a function of the first and second power signals, P0 and P1, a signal indicative of whether the particular transmission impairment affected the levels of individual ones of the incoming channel signals. If so, then control apparatus offsets the impairment accordingly.

Abstract: The monitoring of regulated redundant power supplies is enhanced by returning to each power supply a feedback (sensed) voltage signal that is indicative of the voltage level that the respective power supply is outputting and the voltage level supplied to a system load. In one embodiment, a feedback signal that is supplied to a power supply as the sensed signal is derived using a voltage divider network across the output of the power supply and a common connection at which the outputs of the power supplies are “Ored” for delivery to the system load. In this way, each power supply regulates its output voltage as a function of the level of the feedback signal and the level of a respective preset signal.

Abstract: The temperature of a thermo-electric cooler that is used to cool a laser is effectively controlled using a monitor which accurately and continuously measures the temperature of the thermo-electric cooler and using apparatus that determines the difference between the measured temperature and a desired thermo-electric cooler temperature. A discriminator circuit causes the thermo-electric cooler to enter (a) a heating cycle when such difference is below a first reference level or (b) a cooling cycle when such difference reaches a reaches a second reference level. Power consumption within the associated cooling/heating system is also accurately controlled using a pulse width modulated power supply to provide the voltage signal that drives the thermoelectric cooler.

Abstract: The invention relates to apparatus for precisely aligning an optical device, i.e., a light source or receptor, to an optical fiber. In one embodiment, the apparatus comprises a header (10) having a plateau (11) for mounting the device (15) and a trough (12) for positioning of the optical fiber (19). The depth (D) of the trough is precisely configured so that the alignment process is limited to adjustment in only one direction (L-L'). A second embodiment (30) allows for the hermetic enclosure of the optical device and adjacent section of optical fiber while providing the same alignment advantage.