Abstract: An adaptive filtering arrangement for providing bit-synchronous, time-dependent filtering of a time-varying analog input signal taking the form of a time-dependent low pass filter including at least one adaptive resistive element that exhibits a varying resistance value as a function of a time. The time-dependent low pass filter uses as a “control” input a modifying element responsive to a clock signal associated with the received signal for creating a time-varying control signal applied as an input to the adaptive resistive element. The time-varying control signal is created to be synchronous with a baud interval of a created output signal such that the instantaneous bandwidth of the time-dependent low pass filter is synchronous with the baud interval, exhibiting a relatively small bandwidth during a central portion of the baud interval and exhibiting a relatively large bandwidth during a transition from one baud interval to the next.

Abstract: A receiver including an amplifying section for converting a relatively low power digital input signal into a relatively high power digital output signal is configured to utilize an adjustable feedback signal that is synchronous with the bit rate of the incoming digital signal so as to modify the level of the feedback signal as a function of time along the width of each bit of the digital input signal, increasing the bandwidth of the receiver at the leading edge of each incoming bit and decreasing the bandwidth otherwise.

Abstract: In accordance with illustrative embodiments, methods and apparati, which determine jitter are described. In one example embodiment, a method includes receiving a signal, wherein the signal comprises a first data pattern which was generated at a first bit rate. The method also includes sampling the signal at a second bit rate to generate a second data pattern. The period of the second bit rate is different from the period of the first bit rate. The method also includes comparing the first data pattern and the second data pattern to determine differences between the first data pattern and the second data pattern. Furthermore, the method includes determining jitter in the signal according to the differences between the first data pattern and the data second data pattern. In other embodiments, by using two different bit rates to determine jitter, jitter can be determined in communication systems in a convenient and cost effective manner.

Abstract: A testing apparatus for testing optical components includes an optical transmitter, an optical attenuator, an optical power meter and an optical receiver which are substantially rigidly coupled in a fixed relation to each other within a single housing. The system permits the common control of all the optical components such that calibration, testing and troubleshooting may be performed using a common user interface. The testing apparatus is unitary, compact and portable, and is a much more robust testing apparatus than conventional schemes.

Abstract: A system and method for bit error rate testing optical components comprises providing an optical testing unit, which measures a bit error rate of an optical device under test (DUT) over an operating range of the DUT. The optical testing unit includes an optical transmitter, which transmits an optical test signal that is transmitted to the DUT; an optical receiver, which receives an input signal from the DUT; a graphical user interface, which provides an interface with a user; and a controller, selectively coupled to the transmitter, the receiver and the graphical user interface, wherein the controller provides a central control of the transmitter, the receiver and the graphical user interface.

Abstract: An error analysis tester for an optical component includes an optical transmitter, an optical attenuator, a port, a receiver, a processor and a graphical display. The optical transmitter and optical attenuator produce a test signal at a plurality of selected optical power levels. The port is configured to output the test signal to the optical component and to receive a version of the test signal from the optical component. The receiver determines errors in the received version of the test signal. The processor determines data points of a function associated with an error rate at each of the selected power levels and a line corresponding to the data points. The graphical display produces a visual plot of the data points and the corresponding line.

Abstract: A system and method for testing the sensitivity of optical components comprises providing an optical testing unit which measures the sensitivity of an optical device under test (DUT). The optical testing unit includes an optical transmitter, which transmits an optical test signal that is transmitted to the DUT; an optical receiver, which receives an input signal from the DUT; a graphical user interface, which provides an interface with a user; and a controller, selectively coupled to the transmitter, the receiver and the graphical user interface, wherein the controller provides a central control of the transmitter, the receiver and the graphical user interface.

Abstract: A system and method for testing the sensitivity of optical components comprises providing an optical testing unit which measures the sensitivity of an optical device under test (DUT). The optical testing unit includes an optical transmitter, which transmits an optical test signal that is transmitted to the DUT; an optical receiver, which receives an input signal from the DUT; a graphical user interface, which provides an interface with a user; and a controller, selectively coupled to the transmitter, the receiver and the graphical user interface, wherein the controller provides a central control of the transmitter, the receiver and the graphical user interface.

Abstract: A system and method for bit error rate testing optical components comprises providing an optical testing unit, which measures a bit error rate of an optical device under test (DUT) over an operating range of the DUT. The optical testing unit includes an optical transmitter, which transmits an optical test signal that is transmitted to the DUT; an optical receiver, which receives an input signal from the DUT; a graphical user interface, which provides an interface with a user; and a controller, selectively coupled to the transmitter, the receiver and the graphical user interface, wherein the controller provides a central control of the transmitter, the receiver and the graphical user interface.

Abstract: A device and method that performs error analysis of an optical component. An optical transmitter transmits a test signal at a plurality of selected optical power levels. A port outputs the test signal to the optical component, and then receives a version of the test signal from the optical component. A receiver determines errors in the received version of the test signal. A processor determines an error rate at each of the selected optical power levels based on the determined errors, and also determines an uncertainty range for each determined error rate. An interface provides indication of the determined error rates in relation to the determined uncertainty ranges.

Abstract: A system and method for bit error rate testing optical components comprises providing an optical testing unit, which measures a bit error rate of an optical device under test (DUT) over an operating range of the DUT. The optical testing unit includes an optical transmitter, which transmits an optical test signal that is transmitted to the DUT; an optical receiver, which receives an input signal from the DUT; a graphical user interface, which provides an interface with a user; and a controller, selectively coupled to the transmitter, the receiver and the graphical user interface, wherein the controller provides a central control of the transmitter, the receiver and the graphical user interface.

Abstract: A system and method for testing the sensitivity of optical components comprises providing an optical testing unit which measures the sensitivity of an optical device under test (DUT). The optical testing unit includes an optical transmitter, which transmits an optical test signal that is transmitted to the DUT; an optical receiver, which receives an input signal from the DUT; a graphical user interface, which provides an interface with a user; and a controller, selectively coupled to the transmitter, the receiver and the graphical user interface, wherein the controller provides a central control of the transmitter, the receiver and the graphical user interface.

Abstract: A testing apparatus and method useful in measuring the performance of a receiver when receiving a relatively high frequency jittered signal. A relatively high frequency oscillator is locked to a relatively low frequency reference with intentional jitter induced by adding jitter to the relatively low frequency reference. A divide by N circuit and a phase/frequency detector are used to detect discrepancies between the relatively low frequency reference output of the oscillator and to generate a signal used to keep the oscillator locked to the relatively low frequency reference. The addition of the jitter to the relatively low frequency reference may be controlled through digital or analog means.

Abstract: A device and method that performs error analysis of an optical component. An optical transmitter transmits a test signal at a plurality of selected optical power levels. A port outputs the test signal to the optical component, and then receives a version of the test signal from the optical component. A receiver determines errors in the received version of the test signal. A processor determines an error rate at each of the selected optical power levels based on the determined errors, and also determines an uncertainty range for each determined error rate. An interface provides indication of the determined error rates in relation to the determined uncertainty ranges.

Abstract: An optical receiver is formed to include a digitally-controlled preamplifier that is used to adjust the bandwidth of the receiver. A measured bandwidth of the receiver is compared to a desired bandwidth and a digital control signal (such as a voltage, current, or any other appropriate parameter) supplied to the preamplifier is thereafter adjusted (either increased or decreased) to increase/decrease the bandwidth of the receiver to the desired value. A voltage regulator and potentiometer may be used as the digital controller and coupled to the input voltage supply of the preamplifier to provide the needed adjustment in voltage.

Abstract: An error analysis tester for an optical component includes an optical transmitter, an optical attenuator, a port, a receiver, a processor and a graphical display. The optical transmitter and optical attenuator produce a test signal at a plurality of selected optical power levels. The port is configured to output the test signal to the optical component and to receive a version of the test signal from the optical component. The receiver determines errors in the received version of the test signal. The processor determines data points of a function associated with an error rate at each of the selected power levels and a line corresponding to the data points. The graphical display produces a visual plot of the data points and the corresponding line.

Abstract: A testing apparatus for testing optical components includes an optical transmitter, an optical attenuator, an optical power meter and an optical receiver which are substantially rigidly coupled in a fixed relation to each other within a single housing. The system permits the common control of all the optical components such that calibration, testing and troubleshooting may be performed using a common user interface. The testing apparatus is unitary, compact and portable, and is a much more robust testing apparatus than conventional schemes.