Abstract: An analog signal generating source comprising two or more digital-to-analog converters (DAC) combined to generate one or more frequency components. The analog signal source comprises a first path for generating substantially low frequency signals, the first path comprising a first one of the DACs; and a second path for generating substantially high frequency signals, the second path comprising a second one of the DACs. The analog signal source also comprises a data processor for processing an input signal and providing the processed input signal to the first and second paths; a combining circuit configured to combine outputs of the first and second paths into the source signal; a feedback portion configured to sense the source signal; and a servo loop configured to use the sensed source signal to adjust as need to maintain the source signal to substantially agree with the input signal.

Abstract: A magnetic field magnetic field sensor and method of making the sensor. The sensor and method of making the sensor may comprise a material or structure that prevents the admission of light in certain wavelengths to enhance the stability of the magnetic field sensor over a period of time. The sensor and method of making the sensor may comprise an adsorption prevention layer which protects the semiconductor portion of the magnetic. The sensor may also comprise an insulating layer formed between semiconductor layers and a substrate layer.

Abstract: A measurement system includes a source unit to provide a source signal to a sample and a voltage source and/or a current source and a memory. The system also includes a measurement unit configured to acquire from the sample an measurement signal that may be responsive to the source signal and a voltage measuring unit, a current measuring unit, and/or a capacitance measuring unit, and a memory. The system also includes a control unit including a digital signal processing unit; a source converter; a measurement converter. The system further includes a synchronization unit configured to synchronize clocks of the digital signal processing unit, the source converter, the measurement converter, the source unit, and the measurement unit; a calibration unit for calibrating aspects of the system including the control unit; and a reference voltage supply configured to supply a common reference voltage for the control unit.

Abstract: A magnetic field magnetic field sensor and method of making the sensor. The sensor and method of making the sensor may comprise a material or structure that prevents the admission of light in certain wavelengths to enhance the stability of the magnetic field sensor over a period of time. The sensor and method of making the sensor may comprise an adsorption prevention layer which protects the semiconductor portion of the magnetic. The sensor may also comprise an insulating layer formed between semiconductor layers and a substrate layer.

Abstract: A measurement system includes a gain chain configured to amplify an analog input signal; a range selector configured to select a gain between the analog input signal and a plurality of analog-to-digital converter (ADC) outputs from a plurality of ADCs, wherein each ADC output has a path, and a gain of each output path is made up of a plurality of gain stages in the gain chain; and a mixer configured to combine the plurality of ADC outputs into a single mixed output.

Abstract: A method and system for measuring Hall effect in a material includes measuring a voltage in two test states, each state alternating the direction and orientation of a current applied across the material or the voltage measured across the material relative to a magnetic field in each state. According to an embodiment, the frequency of measurement at each state differs.

Abstract: A method and system for measuring Hall effect in a material includes measuring a voltage in two test states, each state alternating the direction and orientation of a current applied across the material or the voltage measured across the material relative to a magnetic field in each state. According to an embodiment, the frequency of measurement at each state differs.

Abstract: Sensors operate by resolving changes in orientation of a wavelength dependent structure with respect to a reference direction determined by an incident light beam, resulting in very high sensitivity and dynamic range. Said sensors are wavelength encoded, can be multiplexed in a single light path such as an optical fiber, yet are decoupled mechanically from the fiber, resulting in high stability.

Abstract: Optical fiber anchors accomplishing low creep confinement or fixing of a section of optical fiber in an assembly compact enough to be used conveniently as an anchor or as an enabling part of a strain or temperature sensor while retaining low optical losses and the original buffer coating to prevent the fiber from being exposed to abrasion and other influences that could lead to breakage. A rigid body is used that is mechanically stiff and hard enough to prevent the fiber from cutting into it or distorting the medium or substrate when subjected to stress, even over a long period of years. Trapping can be accomplished by molding the bent fiber into the substrate or body, adhesively bonding or soldering the optical fiber into a confining curved groove in a body or substrate.

Abstract: Optical fiber anchors accomplishing low creep confinement or fixing of a section of optical fiber in an assembly compact enough to be used conveniently as an anchor or as an enabling part of a strain or temperature sensor while retaining low optical losses and the original buffer coating to prevent the fiber from being exposed to abrasion and other influences that could lead to breakage. A rigid body is used that is mechanically stiff and hard enough to prevent the fiber from cutting into it or distorting the medium or substrate when subjected to stress, even over a long period of years. Trapping can be accomplished by molding the bent fiber into the substrate or body, adhesively bonding or soldering the optical fiber into a confining curved groove in a body or substrate.

Abstract: Optical fiber anchors accomplishing low creep confinement or fixing of a section of optical fiber in an assembly compact enough to be used conveniently as an anchor or as an enabling part of a strain or temperature sensor while retaining low optical losses and the original buffer coating to prevent the fiber from being exposed to abrasion and other influences that could lead to breakage. A rigid body is used that is mechanically stiff and hard enough to prevent said fiber from cutting into it or distorting said medium or substrate when subjected to stress, even over a long period of years. Trapping can be accomplished by molding the bent fiber into the substrate or body, adhesively bonding or soldering the optical fiber into a confining curved groove in a body or substrate.

Abstract: To eliminate or otherwise reduce unintended movement of a probe tip of a probe assembly being held by a probe arm, the probe assembly includes one or more resilient members that compensate for the contraction or expansion of the probe arm in accordance with the coefficient of thermal expansion of the material from which the probe arm is made. Thus, the probe tip can remain in contact with a sample being measured at the desired location on the sample, during an automated full or wide scale temperature range sweep.

Abstract: Sensors operate by resolving changes in orientation of a wavelength dependent structure with respect to a reference direction determined by an incident light beam, resulting in very high sensitivity and dynamic range. Said sensors are wavelength encoded, can be multiplexed in a single light path such as an optical fiber, yet are decoupled mechanically from the fiber, resulting in high stability.

Abstract: A compact, optically double-ended sensor probe with at least one 180° bend provided in the optical fiber in close proximity to a fiber Bragg grating temperature sensor suspends the optical fiber within a casing in such a way that the expansion and contract of the probe casing will not materially influence the temperature reading of the fiber Bragg grating by adding time varying or temperature varying stress components.

Abstract: One-dimensional, two-dimensional and three-dimensional negative refractive index (NRI) and/or opto-magnetic materials operating in spectral ranges spanning from the visible to far IR wavelength ranges is disclosed. Said materials are comprised of metal or metal/dielectric wire pairs arranged in a number of sublattices (one for one dimensional material, two for two-dimensional and three or more for three dimensional material), such that in each lattice, said wire pairs are essentially parallel to each other. Such a materials are useful and practical in obtaining previously unachievable important optical functions in these spectral ranges. Such optical properties are highly desired for many applications. A practical means of manufacture that is compatible with cost-effective and large-scale production methods is also provided.

Abstract: A compact, optically double-ended sensor probes with at least one 180° bend provided in the optical fiber in close proximity to a fiber Bragg grating temperature sensor suspends the optical fiber within a casing in such a way that the expansion and contract of the probe casing will not materially influence the temperature reading of the fiber Bragg grating by adding time varying or temperature varying stress components.

Abstract: A method of manufacture for optical spectral filters with omnidirectional properties in the visible, near IR, mid IR and/or far IR (infrared) spectral ranges is based on the formation of large arrays of coherently modulated waveguides by electrochemical etching of a semiconductor wafer to form a pore array. Further processing of said porous semiconductor wafer optimizes the filtering properties of such a material. The method of filter manufacturing is large scale compatible and economically favorable. The resulting exemplary non-limiting illustrative filters are stable, do not degrade over time, do not exhibit material delamination problems and offer superior transmittance for use as bandpass, band blocking and narrow-bandpass filters. Such filters are useful for a wide variety of applications including but not limited to spectroscopy, optical communications, astronomy and sensing.

Abstract: Methods and apparatus for providing closed-loop control over an electrochemical etching process during porous semiconductor fabrication enhance the quality of the porous semiconductor materials, especially those contained structural variations (such as porosity or morphology variations) along the thickness of said porous semiconductors. Such enhancement of the control over the electrochemical etching process is highly desired for many applications of porous semiconductor materials.

Abstract: A method of enhancing the conversion of magnetic field intensity and spatial data to optical data utilizes surface plasmon resonance combined with corrugated optical gratings of several types. Appropriate materials and methods for producing and applying said corrugations and surface plasmon resonance-producing enhancements to Magneto-Optical Indicator Films (MOIF) are described. Methods of acquiring and interpreting magneto-optical data are also described.

Abstract: A waveguide magneto-optic sensor provides a signal indicative of the value and/or direction of a detected magnetic field by a spectral shift of the characteristic resonant spectral feature of the sensor is disclosed. The sensor does not suffer from vibrations, fiber bending or other light intensity noise and provides an absolute self-referencing signal. The sensor elements can easily be coupled to optical fibers and read with scanning spectrometers or scanning lasers calibrated against NIST-traceable gas absorption standards.