Abstract: A test apparatus and a method for operating a data processing system to generate a test signal for testing a DUT are disclosed. The apparatus includes a signal generator, artificial neural network, and controller. The signal generator generates a test signal determined by a plurality of signal generator input parameters, X, that are coupled thereto. The test signal is characterized by a plurality of calculated parameters, Y. The artificial neural network has the calculated parameters as inputs and a plurality of outputs connected to the plurality of signal generator inputs. The controller receives desired values for the calculated parameters and couples those desired values to the neural network inputs, thereby causing the test signal generator to generate a test signal having the desired values for the calculated parameters.

Abstract: An arbitrary waveform generator (AWG) comprises a real-time digital signal processor (DSP) configured to process a stream of waveform data based on current values of processing parameters, a DSP memory configured to store information related to the processing parameters, and an update component configured to update in real-time the current values of the processing parameters based on the information stored in the DSP memory.

Abstract: A method of determining polarization dependent characteristic of an optical device under test (10) having at least one input and at least one output, comprises the steps of generating and inputting a stimulus signal (4) to each of a plurality of polarization units (27a, 29b, 127c, 129d), setting each of said input stimulus signals into a unique state of polarization, attaching a characteristic identification portion (27, 29, 127, 129) to each of said input and/or polarized stimulus signals, applying said stimulus signal to said device under test (10) for effecting a response signal of said device under test, receiving and identifying (44, 52) each of said characteristic identification portions from said response signal for tracing each of said polarized stimulus signals within said response signal, deriving a polarization dependent characteristic of said device under test from said traced polarized stimulus signals.

Abstract: An apparatus and a method of polarization dependent analyzation of an optical signal transmitted through a DUT includes splitting the optical signal into a first signal part having an initial first polarization and a second signal part having an initial second polarization, coding the first signal part using a first code and coding the second signal part using a second code, providing the coded signal parts to the DUT, detecting a DUT-signal coming from the DUT in response to the coded signal parts, and determining a first part of the DUT-signal corresponding to the first signal part by means of the first code and determining a second part of the DUT-signal corresponding to the second signal part by means of the second code.

Abstract: In order to reduce polarization dependent error, the polarization state of incident light is set to at least two different states of polarization, and a first optical property is determined separately for each of said at least two states of polarization. Then, an averaging procedure is carried out in order to obtain a mean value of the first optical property or of a property derived therefrom. Alternatively, the averaging procedure can be performed with respect to a DUT property of a device under test that is determined as a function of said first optical property.

Abstract: A method of manipulating an optical signal includes a) splitting the optical signal into a first signal and a second signal, b) using the second signal as a signal undelayed with respect to the optical signal, c) delaying the first signal with respect to the second signal, d) splitting the first signal into a first and a second part, e) using the second part of the first signal as a delayed signal, and f) repeating steps a)-d) with the first part of the first signal.

Abstract: An apparatus and method of controlling an optical signal includes superimposing at least one optical reference signal and the optical signal to obtain at least one interference signal having an actual beat frequency, and pre-selecting one or more of the at least one interference signals using a predetermined bandwidth and a filter characteristic that is asymmetric with respect to an actual frequency of the optical signal, to determine a position of the optical signal relative to the at least one optical reference signal.

Abstract: The invention relates to a method of tuning a laser, comprising the steps of: providing a laser beam (4) in an external cavity (2) having a dispersion element (10) for selecting at least one mode of the laser, varying the wavelength characteristic of the dispersion element (10).

Abstract: The present invention relates to an apparatus and to a method of controlling an optical signal, comprising the steps of determining at least one actual beat frequency derived from a superposition of at least one optical reference signal with the optical signal having an actual frequency, and using the at least one actual beat frequency in order to control the actual frequency.

Abstract: In order to reduce polarization dependent error, the polarization state of incident light is set to at least two different states of polarization, and a first optical property is determined separately for each of said at least two states of polarization. Then, an averaging procedure is carried out in order to obtain a mean value of the first optical property or of a property derived therefrom. Alternatively, the averaging procedure can be performed with respect to a DUT property of a device under test that is determined as a function of said first optical property.