Abstract: A method for measuring in-band crosstalk in an optical amplifier, such as a Raman amplifier, in which a modulated optical signal is generated using an input modulator. The modulated optical signal is passed through the optical amplifier to obtain a first output optical signal, the power level of which is measured when the input modulator is in its off-state. The modulated optical signal is then attenuated by a factor equal to the extinction ratio of the input modulator to obtain an attenuated modulated optical signal which is passed through the optical amplifier to obtain a second output optical signal. The power level of the second output optical signal is measured when the input modulator is in its on-state. The in-band crosstalk is calculated by subtracting the power level of the second output optical signal from the power level of the first output optical signal.

Abstract: An alignment system that uses a single optical sensor to enable the end of an optical fiber to be aligned with the input of an optical waveguide of an optical device. In accordance with the present invention, it has been determined that the output of a single optical sensor can be processed and converted into digital signals, which are then further processed in accordance with an alignment algorithm to generate feedback signals that enable precise alignment to be achieved. The alignment system includes the single optical sensor, a lens and processing logic.

Abstract: An optical system for detecting and coupling light to optical devices, and a method for aligning and calibrating the system. The system includes positioning stages and fiber sensors. The fiber sensors are used to detect the positions of calibration pieces and other sensors in a variety of configurations. From these detected positions, any misalignment of the sensors or positioning stages may be calculated and corrected for. The fiber sensors calibrate the system.

Abstract: An edge detector with sub-micron accuracy. The edge detector comprises two single mode optical fibers with an optical path between them. One fiber is coupled to a laser light source, and creates a light beam. The other fiber is coupled to an optical power detector. The optical power reaching the optical power detector is determined by how much of the light beam is obscured by an object. Thus the position of the edge of the object may be determined from the optical power measured by the detector. The edge of an object may be positioned automatically according to the optical power measured by the detector.

Abstract: An alignment system that uses a single optical sensor to enable the end of an optical fiber to be aligned with the input of an optical waveguide of an optical device. In accordance with the present invention, it has been determined that the output of a single optical sensor can be processed and converted into digital signals, which are then further processed in accordance with an alignment algorithm to generate feedback signals that enable precise alignment to be achieved. The alignment system includes the single optical sensor, a lens and processing logic.

Abstract: Fiber optic alignment methods and apparatus in accordance with the present invention first identify a target beam width incidence on an end of an optical element. The end of the optical element is placed into a beam of light at an axial location relative to the beam of light. The end of the optical element is subsequently moved transversally (perpendicular) to the beam of light until a position of maximum optical power, as measured through the optical element, is identified. A beam width of the beam of light is measured at that axial location. The movement and measurement sequence is repeated at multiple axial locations relative to the beam of light. Linear regression, or an equivalent approach is used, to predict an axial location relative to the beam of light with the target beam width. The end of the optical element is then moved to the axial location with the target beam width.

Abstract: An edge detector with sub-micron accuracy. The edge detector comprises two single mode optical fibers with an optical path between them. One fiber is coupled to a laser light source, and creates a light beam. The other fiber is coupled to an optical power detector. The optical power reaching the optical power detector is determined by how much of the light beam is obscured by an object. Thus the position of the edge of the object may be determined from the optical power measured by the detector. The edge of an object may be positioned automatically according to the optical power measured by the detector.

Abstract: A method and system for measuring in-band crosstalk in an optical amplifier, such as a Raman amplifier, in which a modulated optical signal is generated using an input modulator. The extinction ratio of the input optical modulator is measured. The modulated optical signal is passed through the optical amplifier to obtain a first output optical signal, the power level of which is measured when the input modulator is in its off-state. The modulated optical signal is then attenuated by a factor equal to the extinction ratio of the input modulator to obtain an attenuated modulated optical signal which is passed through the optical amplifier to obtain a second output optical signal. The power level of the second output optical signal when the input modulator is in its on-state. The in-band crosstalk is calculated by subtracting the power level of the second output optical signal from the power level of the first output optical signal. The input and output modulators may be acousto-optic modulators.

Abstract: An alignment system that uses a single optical sensor to enable the end of an optical fiber to be aligned with the input of an optical waveguide of an optical device. In accordance with the present invention, it has been determined that the output of a single optical sensor can be processed and converted into digital signals, which are then further processed in accordance with an alignment algorithm to generate feedback signals that enable precise alignment to be achieved. The alignment system includes the single optical sensor, a lens and processing logic.

Abstract: A measurement system is provided that is capable of analyzing light at the input of an optical waveguide of an optical device under test (DUT) and/or at the output of the waveguide, preferably at both. At the input of the waveguide, light having a particular polarization state generated by a polarization controller is output from the polarization controller and coupled into a proximal end of an optical fiber. The measurement system analyzes the polarization state of the light being launched from the opposite, or distal, end of the optical fiber into the waveguide input of the DUT to determine whether and by how much the polarization state of the light has been changed by the optical fiber. The polarization controller is altered, if necessary, to compensate for any changes in the polarization state caused by the optical fiber so that the polarization state of light being launched into the input of the optical fiber is known and is controllable.

Abstract: Fiber optic alignment methods and apparatus in accordance with the present invention first identify a target beam width incidence on an end of an optical element. The end of the optical element is placed into a beam of light at an axial location relative to the beam of light. The end of the optical element is subsequently moved transversally (perpendicular) to the beam of light until a position of maximum optical power, as measured through the optical element, is identified. A beam width of the beam of light is measured at that axial location. The movement and measurement sequence is repeated at multiple axial locations relative to the beam of light. Linear regression, or an equivalent approach is used, to predict an axial location relative to the beam of light with the target beam width. The end of the optical element is then moved to the axial location with the target beam width.

Abstract: A measurement system is provided that is capable of analyzing light at the input of an optical waveguide of an optical device under test (DUT) and/or at the output of the waveguide, preferably at both. At the input of the waveguide, light having a particular polarization state generated by a polarization controller is output from the polarization controller and coupled into a proximal end of an optical fiber. The measurement system analyzes the polarization state of the light being launched from the opposite, or distal, end of the optical fiber into the waveguide input of the DUT to determine whether and by how much the polarization state of the light has been changed by the optical fiber. The polarization controller is altered, if necessary, to compensate for any changes in the polarization state caused by the optical fiber so that the polarization state of light being launched into the input of the optical fiber is known and is controllable.

Abstract: An alignment system that uses a single optical sensor to enable the end of an optical fiber to be aligned with the input of an optical waveguide of an optical device. In accordance with the present invention, it has been determined that the output of a single optical sensor can be processed and converted into digital signals, which are then further processed in accordance with an alignment algorithm to generate feedback signals that enable precise alignment to be achieved. The alignment system includes the single optical sensor, a lens and processing logic.

Abstract: An optical system for detecting and coupling light to optical devices, and a method for aligning and calibrating the system. The system includes positioning stages and fiber sensors. The fiber sensors are used to detect the positions of calibration pieces and other sensors in a variety of configurations. From these detected positions, any misalignment of the sensors or positioning stages may be calculated and corrected for. The fiber sensors calibrate the system.

Abstract: An edge detector with sub-micron accuracy. The edge detector comprises two single mode optical fibers with an optical path between them. One fiber is coupled to a laser light source, and creates a light beam. The other fiber is coupled to an optical power detector. The optical power reaching the optical power detector is determined by how much of the light beam is obscured by an object. Thus the position of the edge of the object may be determined from the optical power measured by the detector. The edge of an object may be positioned automatically according to the optical power measured by the detector.

Abstract: An edge detector with sub-micron accuracy. The edge detector comprises two single mode optical fibers with an optical path between them. One fiber is coupled to a laser light source, and creates a light beam. The other fiber is coupled to an optical power detector. The optical power reaching the optical power detector is determined by how much of the light beam is obscured by an object. Thus the position of the edge of the object may be determined from the optical power measured by the detector. The edge of an object may be positioned automatically according to the optical power measured by the detector.