Abstract: A container holds an item. The item has an upper surface with a contacting portion and a non-contacting portion. The container comprises a base and a cover. The base has a lower retaining portion with a depth. The item is removably engagable into the lower retaining portion of the base. The cover has an upper retaining portion with a contacting portion and a non-contacting portion. The cover is removably engagable with the base so that the upper retaining portion of the cover is aligned with the lower retaining portion of the base. When the contacting portion of the upper retaining portion of the cover is engaged with the contacting portion of the item, the non-contacting portion of the upper retaining portion is separated from the non-contacting portion of the item by a gap.

Abstract: A fiber winding and storage assembly is disclosed. The fiber winding and storage assembly includes a fiber winding fixture and a fiber storage device. The fiber winding fixture may include a winding structure, a handle member, and a mounting member. The winding structure has a first side and a second side where the first side defines a recess therein. The handle member is disposed on the second side of the winding structure. The mounting member is disposed within the recess of the winding structure and extends perpendicularly therefrom. The fiber storage device is received within the recess of the fiber winding fixture. In a second embodiment for the fiber winding fixture, the winding fixture also includes a push button and a biasing member. The push button is mounted in the handle member and biased to a first position within the fiber winding fixture.

Abstract: A method is provided for transmitting an optical signal in an optical communication system. The system includes a transmitter for generating the optical signal, a receiver for detecting the signal, and an optical fiber communication link interposed between the transmitter and receiver. The optical fiber communication link includes transmission optical fibers concatenated with a plurality of Raman amplifiers and at least one rare earth doped optical fiber amplifier. The method includes the steps of: amplifying the optical signal as it advances through each of the plurality of Raman amplifiers; and compensating for variations in transmission path losses to restore the optical signal to a nominal power level as it advances through the rare earth doped optical fiber amplifier by maintaining the doped optical fiber amplifier in its saturated state.

Abstract: A path couples a pair of optical fibers in an optical transmission system. The transmission system includes a plurality of optical amplifiers placed along the transmission line. Associated with these optical amplifiers are optical isolators that limit the flow of optical energy to a single direction. The path allows reflected or scattered light from one optical fiber after the optical isolator to be returned via the other optical fiber. This enables an OTDR device to obtain measurement information along the entire length of the fibers between optical isolators.

Abstract: An optical transmission system allows for the remote determination of the total output power of each repeater. The optical transmission system includes two terminals, an optical path that transmits a plurality of optical signals between the two terminals, and a plurality of repeaters spaced along the optical path. In each of the repeaters, pilot signals are inserted by impressing them upon the amplified optical signals output from the repeater. The pilot signals are derived from an oscillator whose frequency is unique to the repeater in which the pilot signals are inserted. The magnitude of each pilot signal is proportional to the output power of its associated repeater. Each terminal provides a measurement of the total power output from each repeater using a receiving device. The receiving device selects the unique oscillator frequency for each of the repeaters desired to be measured, and measures the pilot signals at the selected frequency.

Abstract: A source/transmission fiber strategy results in a WDM system with negligible FWM penalty even for closely-spaced channels. The combined performance of a source which provides chirped wavelength pulses with a precise synchronism, along with a transmission fiber dispersion map avoids pulse overlap.

Abstract: A dual-stage doped fiber amplifier is provided which utilizes a single pump laser and a passive power splitter to pump both amplifier stages. The passive splitter couples a first portion of the power output of the single pump laser to a first stage amplifier and a second portion of the pump power to the second stage. In this manner, the performance characteristics of the amplifier can be controlled by utilizing a single pump source.

Abstract: A pressure testing apparatus can pressure test separately a first object having a width and a height and a second object having a width and a height. The first object can be, for example, a fiber optic repeater; the second object can be, for example, a fiber optic branch unit. The pressure testing apparatus has a testing vessel and an adaptor. The testing vessel has a chamber with an inner width corresponding to the width of the first object and a first gap. The adaptor can be selectably insertable into the chamber of the testing vessel and has an inner width and an outer width. The outer width of the adaptor corresponds to the inner width of the chamber of the testing vessel and a second gap. The inner width of the adaptor corresponds to the width of the second object and a third gap.

Abstract: A "floating" fiber storage assembly is provided for use with a fiber-optic cable joint that connects two or more cables. The device includes a fiber storage tray for storing the spliced optic fibers of the cables, although any fiber storage device (such as a cylinder) may be used. The fiber storage tray has a locking end with a connection interface, comprised of one or more locking cut-outs and locking tabs, for slidably engaging a terminating socket assembly. When the connection interface is slidably engaged with the terminating socket assembly, the fiber storage tray is loosely connected to the terminating socket assembly. To prevent the fiber storage tray and the terminating socket assembly from easily disengaging, a locking band may engage a substantially continuous locking groove formed when the storage tray and the socket assembly are loosely connected.

Abstract: Chromatic dispersion in an optical cable is measured by applying to the cable a signal that rapidly switches between a wavelength generated by a tunable optical source and a different wavelength generated by a reference source. The two sources are modulated in such a way that a delay line phase detection scheme at the far end of the cable can accurately measure relative delay between the tunable source and the reference source. The chromatic dispersion is determined by measuring the relative delay between the two sources for several different wavelengths of the tunable source.

Abstract: An improved monitoring system for monitoring a fiber optic transmission system using optical side tones. The monitoring system includes a line monitoring equipment (LME) connected to a portion of an optical transmission system. The LME includes a pseudo-random sequence (PRS) tone generator for generating a PRS tone, a laser transmitter for transmitting an LME optical side tone based on the PRS tone. The LME includes a delay system for delaying the PRS tones, an optical filter for passing only the wavelength of the LME side tone. A plurality of data channels are transmitted over the system using WDM. A coupler is used to combine the WDM data with the LME side tone. A repeater having an optical loopback coupler returns a portion of the combined signal to the LME. The comparator/correlator correlates the delayed PRS tones with the LME side tone returned by each repeater.

Abstract: The in-fiber safety interlock system includes a high power (Class IV) laser interlocked to an OTDR. A plurality of WDM data signals are transmitted over the fiber system, including a terminal portion and an extended portion. A control circuit is connected to the laser and the OTDR. The OTDR monitors the integrity of the fiber system, including both the terminal portion and the extended portion. If the OTDR detects a fault in the optical transmission path, the OTDR and the control circuit operate to automatically disable or shut down the laser.

Abstract: An apparatus is provided for transmitting an optical signal. The apparatus includes an optical signal source for generating an optical signal having a plurality of optical channels onto which data is modulated at a plurality of predetermined frequencies to provide a plurality of optical data channels. An amplitude modulator is coupled to the optical signal source for modulating each of the optical channels with a waveform that is independently adjustable from one another. A clock, coupled to the amplitude modulator, has a plurality of frequencies that respectively determine the modulation frequencies imparted to the plurality of optical channels by the amplitude modulator. Each of the frequencies of the clock is phase locked and equal to its respective predetermined frequency at which is data is modulated.

Abstract: An OTDR provides both in-service and out-of-service measurement information for an optical transmission system with multiple repeaters. The repeaters include an optical high-loss loop back (HLLB) path and an OTDR path. The OTDR is coupled to the input lines of the optical transmission system via an optical coupler so that both traffic signals and test signals from the OTDR can be transmitted simultaneously. When the OTDR is providing in-service measurement information, test signals in the form of side-tone pulses are transmitted on the transmission system. The wavelengths of the test signals are sufficiently offset from the wavelength of the traffic signal so there is minimal interference between them. The level of the test signals is low relative to the traffic signal to also minimize interference. The OTDR filters out the traffic signal from the returned signal. The HLLB path through the amplifier pairs of each repeater is distinguishable in the filtered returned signal.

Abstract: A method and apparatus is provided for modulating the polarization of an optical signal. A polarization modulator receives an optical signal onto which data has been modulated at a predetermined frequency. The polarization modulator modulates the state of polarization of the optical signal at a frequency phase locked and equal to the same predetermined frequency at which the data is modulated onto the optical signal. The polarization modulation is performed so that the average value of the state of polarization over each modulation cycle is substantially equal to zero.

Abstract: An optical gain block that is pumped by one or more pump input modules is disclosed. Each pump input module includes a pump source, a pump power control circuit and a bus interface. Each of the available pump input modules detect the presence and pump power of other available pump input modules in order to properly adjust the output power of its own pump source. By controlling the power provided by each of the available pump input modules, the gain block output will be maintained at a specified output power level while all pump input modules share in delivering the required total input pump power. Upon the insertion or removal of any pump input module, the remaining pump input modules will adjust their output power accordingly to maintain the gain block output power at the specified level.

Abstract: Disclosed is a redundant TTE optical transmission system architecture which eliminates system signal power loss due to protection elements and thus provides a system power budget comparable to non-redundant TTE systems. Further disclosed is a virtually non-failing optical amplifier, for redundant and non-redundant optical systems, which allows for the simultaneous exploitation of the pump power from both sets of laser pumps in a dual-pump configuration, thereby increasing the available system power margin.