Abstract: A synthesized digital filter and method for synthesizing the digital filter are described herein. In one embodiment of the present invention, the digital filter is made using analog RF components. In another embodiment of the present invention, the digital filter is made using optical components which enables an optical signal to be manipulated in an optical domain without needing to convert the optical signal into an electrical domain.

Abstract: An amplifier characterized by gain and output power comprises: (i) at least one gain medium; (ii) at least one pump supplying optical power into the gain medium; and (iii) a controller controlling the gain and the output power of the amplifier. The controller includes a signal compression circuit to cover a wide dynamic range for optical input and output signals, so that resolution for low optical signals is better than resolution for high optical signals.

Abstract: A synthesized digital filter and method for synthesizing the digital filter are described herein. In one embodiment of the present invention, the digital filter is made using analog RF components. In another embodiment of the present invention, the digital filter is made using optical components which enables an optical signal to be manipulated in an optical domain without needing to convert the optical signal into an electrical domain.

Abstract: An amplifier characterized by gain and output power comprises: (i) at least one gain medium; (ii) at least one pump supplying optical power into the gain medium; and (iii) a controller controlling the gain and the output power of the amplifier. The controller includes a signal compression circuit to cover a wide dynamic range for optical input and output signals, so that resolution for low optical signals is better than resolution for high optical signals.

Abstract: A technique for measuring the current, voltage and phase of a radio frequency (RF) power wave to an RF load, accounts for the finite length of the voltage and current pickups, and corrects for effects of standing wave components of voltage and current. Voltage and current are computed as complex functions of the voltage pickup signal and the current pickup signal, based on coefficients precalibrated for radio frequency. Alternatively, a corrected current value can be based on the corrected voltage value and complex load impedance. The correction coefficients can be obtained, for each of a plurality of calibrating radio frequencies within an RF range, from voltage and current pickup signals under conditions of (a) open circuit load, (b) short circuit load, (c) fixed known impedance load; and (d) one of voltage and current being applied at a precise input level to a know load from an RF calibration source.

Abstract: A monitoring system useful for monitoring the state of a fiber communication channel in which a portion of the fiber signal is tapped and detected by a photodiode. The dark current of the photodiode and other DC offsets of the system may be compensated by passing a known signal through the photodiode and extracting the component due to the known signal. The known signal may be a locally generated optical signal having a predetermined harmonic signature. Optionally, the fiber signal may be selectively attenuated before being combined with the known signal so only the known signal is detected. The known signal may also be a dark signal induced by selectively attenuating the fiber signal. The system may include a temperature sensor which allows the compensation to be performed against stored temperature dependent compensation values while the fiber signal is not attenuated.

Abstract: A monitoring system useful for monitoring the state of a fiber communication channel in which a portion of the fiber signal is tapped and detected by a photodiode. The dark current of the photodiode and other DC offsets of the system may be compensated by passing a known signal through the photodiode and extracting the component due to the known signal. The known signal may be a locally generated optical signal having a predetermined harmonic signature. Optionally, the fiber signal may be selectively attenuated before being combined with the known signal so only the known signal is detected. The known signal may also be a dark signal induced by selectively attenuating the fiber signal. The system may include a temperature sensor which allows the compensation to be performed against stored temperature dependent compensation values while the fiber signal is not attenuated.

Abstract: An amplifier characterized by gain and output power comprises: (i) at least one gain medium; (ii) at least one pump supplying optical power into the gain medium; and (iii) a controller controlling the gain and the output power of the amplifier. The controller includes a signal compression circuit to cover a wide dynamic range for optical input and output signals, so that resolution for low optical signals is better than resolution for high optical signals.

Abstract: A method for compensating for ASE in gain control mode while controlling gain of an optical amplifier, the method including the following steps: (i) obtaining value for input and output power electronic circuitry DC offset; (ii) selecting the following set point values: power set point=0.

Abstract: A technique for measuring the current, voltage and phase of an RF power wave to an RF load, accounts for the finite length of the voltage and current pickups, and corrects for effects of standing wave components of voltage and current. Voltage and current are computed as complex functions of the voltage pickup signal and the current pickup signal, based on coefficients precalibrated for said-predetermined radio frequency. Alternatively, a corrected current value can based on the corrected voltage value and complex load impedance. The correction coefficients can be obtained, for each of a plurality of calibrating radio frequencies within an RF range, from voltage and current pickup signals under conditions of (a) open circuit load, (b) short circuit load, (c) fixed known impedance load; and (d) one of voltage and current being applied at a precise input level to a known load from an RF calibration source.

Abstract: An optical fiber amplifier includes an optical system and an electronic controller. The optical system includes: an optical gain medium; at least one pump source coupled to the optical gain medium; an input port for in-coming signal; and an output port for an out-going signal. It also includes an input optical signal tap coupled to a first optical detector; and an output optical signal tap coupled to a second optical detector. The electronic controller is adapted to utilize inputs received from the tabs to control optical power provided by the pump source. The controller includes a user interface that allows a user to control at least one of the following available functions: desired amplifier gain value; amplifier output power value; ASE noise compensation.

Abstract: A technique for measuring the current, voltage and phase of a Radio Frequency (RF) power wave to an RF load, accounts for the finite length of the voltage and current pickups, and corrects for effects of standing wave components of voltage and current. Voltage and current are computed as complex functions of the voltage pickup signal and the current pickup signal, based on coefficients precalibrated for the predetermined radio frequency. Alternatively, a corrected current value can based on the corrected voltage value and complex load impedance. The correction coefficients can be obtained, for each of a plurality of calibrating radio frequencies within an RF range, from voltage and current pickup signals under conditions of (a) open circuit load, (b) short circuit load, (c) fixed known impedance load; and (d) one of voltage and current being applied at a precise input level to a known load from an RF calibration source.

Abstract: A method for compensating for ASE in gain control mode while controlling gain of an optical amplifier, the method including the following steps: (i) obtaining value for input and output power electronic circuitry DC offset; (ii) selecting the following set point values: power set point=0.

Abstract: An optical fiber amplifier includes an optical system and an electronic controller. The optical system includes: an optical gain medium; at least one pump source coupled to the optical gain medium; an input port for in-coming signal; and an output port for an out-going signal. It also includes an input optical signal tap coupled to a first optical detector; and an output optical signal tap coupled to a second optical detector. The electronic controller is adapted to utilize inputs received from the tabs to control optical power provided by the pump source. The controller includes a user interface that allows a user to control at least one of the following available functions: desired amplifier gain value; amplifier output power value; ASE noise compensation.

Abstract: A sputtering apparatus for depositing a thin film (66) of magnetic material on a substrate (26) is modified to include a plate-shaped electromagnet (34, 44, or 70) for orienting magnetic domains within the film (66). The electromagnet (34, 44, or 70) has conductive windings (38; 46, 48, and 50; or 72) that are arranged for producing a magnetic field (42 or 52) within a plane (60) corresponding to a surface of the substrate (26). Field strength vectors (68) vary in absolute magnitude between points located along a first axis (62), but have substantially uniform components of magnitude at the same points measured in a common direction along the first axis (62).

Abstract: Plasma process control arrangement controls a plasma generator that provides electrical power to a plasma chamber for an RF or DC plasma process. A sensor system detects operating parameters of the electrical power, including voltage and current levels. A process detection system (pds) controller has inputs coupled to the sensor system to receive the operating parameters, a programmable memory unit for storing a control program to compute an output control signal based on the operating parameters, and a control output coupled to a control input of the plasma generator. An external computer device, includes a monitor, an icon copying device for example, a mouse suitable for drag-and-drop operation, and a memory storing a suitable code-building program for generating a user-selected control program according to user-determined process requirements.

Abstract: A sputtering apparatus for depositing a thin film (66) of magnetic material on a substrate (26) is modified to include a plate-shaped electromagnet (34, 44, or 70) for orienting magnetic domains within the film (66). The electromagnet (34, 44, or 70) has conductive windings (38; 46, 48, and 50; or 72) that are arranged for producing a magnetic field (42 or 52) within a plane (60) corresponding to a surface of the substrate (26). Field strength vectors (68) vary in absolute magnitude between points located along a first axis (62), but have substantially uniform components of magnitude at the same points measured in a common direction along the first axis (62).

Abstract: An RF probe for a plasma chamber picks up current and voltage samples of the RF power applied to an RF plasma chamber, and the RF voltage and current waveforms are supplied to respective mixers. A local oscillator supplies both mixers with a local oscillator signal at the RF frequency plus or minus about 15 KHz, so that the mixers provide respective voltage and current baseband signals that are frequency shifted down to the audio range. The phase relation of the applied current and voltage is preserved in the baseband signals. These baseband signals are then applied to a stereo, two-channel A/D converter, which provides a serial digital signal to a digital signal processor or DSP. A local oscillator interface brings a feedback signal from the DSP to the local oscillator. The DSP can be suitably programmed to obtain complex Fast Fourier Transforms of the voltage and current baseband samples.

Abstract: A sputtering apparatus for depositing a thin film (66) of magnetic material on a substrate (26) is modified to include a plate-shaped electromagnet (34, 44, or 70) for orienting magnetic domains within the film (66). The electromagnet (34, 44, or 70) has conductive windings (38; 46, 48, and 50; or 72) that are arranged for producing a magnetic field (42 or 52) within a plane (60) corresponding to a surface of the substrate (26). Field strength vectors (68) vary in absolute magnitude between points located along a first axis (62), but have substantially uniform components of magnitude at the same points measured in a common direction along the first axis (62).

Abstract: An RF probe for a plasma chamber picks up current and voltage samples of the RF power applied to an RF plasma chamber, and the RF voltage and current waveforms are supplied to respective mixers. A local oscillator supplies both mixers with a local oscillator signal at the RF frequency plus or minus about 15 KHz, so that the mixers provide respective voltage and current baseband signals that are frequency shifted down to the audio range. The phase relation to the applied current and voltage is preserved in the baseband signals. These baseband signals are then applied to a stereo, two-channel A/D converter, which provides a serial digital signal to a digital signal processor or DSP. A local oscillator interface brings a feedback signal from the DSP to the local oscillator. The DSP can be suitably programmed to obtain complex Fast Fourier Transforms of the voltage and current baseband samples.