Abstract: A new fiber-optic magnetic field or current sensor design can increase the accuracy, resolution and environmental stability of the subject sensor. The design is based on phase-shifted fiber or planar waveguide Bragg grating, in which a Fabry-Perot resonator is formed around the phase shift. When the wavelength of incident light coincides with the wavelength of FP resonator mode, the magnetic field induced polarization rotation of the waveguided light will be strongly enhanced.

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.

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: The UV, deep UV and/or far UV (ultraviolet) filter transmission spectrum of an MPSi spectral filter is optimized by introducing at least one layer of substantially transparent dielectric material on the pore walls. Such a layer will modify strongly the spectral dependences of the leaky waveguide loss coefficients through constructive and/or destructive interference of the leaky waveguide mode inside the layer. Increased blocking of unwanted wavelengths is obtained by applying a metal layer to one or both of the principal surfaces of the filter normal to the pore directions. The resulting filters are stable, do not degrade over time and exposure to UV irradiation, and offer superior transmittance for use as bandpass filters. Such filters are useful for a wide variety of applications including but not limited to spectroscopy and biomedical analysis systems.

Abstract: Mesoporous silicon optical filters can be used to filter light in the near infrared, mid infrared and/or far infrared spectral ranges. The special advantages of mesoporous filters in cold temperature applications include improved mechanical stability, absence of delamination problems, manufacturability, and transparency of the mesoporous silicon material throughout a wide spectral range. Techniques are disclosed for enhancing the transparency range and environmental and mechanical stabilities of the mesoporous silicon filters.

Abstract: Visible and infra-red spectral filters based on arrays of uncoupled identical waveguides having coherently modulated cross sections offer many unique advantages, such as independence of the spectral position of the Bragg-resonance based transmission or reflection features on the angle of light incidence. The resulting spectral filters are mechanically and optically stable, do not degrade over time, and offer superior transmittance for use as band pass, narrow band pass, band blocking, short pass and long pass filters. Such filters are useful for a wide variety of applications including but not limited to biomedical analysis systems, spectroscopy and optical communications systems.

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 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: Magnetic field and/or electrical current imaging systems utilizing magneto-optical indicator films (MOIF) based on magneto-optical material with in-plane single easy axis type of magnetic anisotropy provide improved magnetic field resolution and dynamic range with the use of specific illumination conditions. Methods that provide the two-dimensional distribution of the external magnetic field vectors are disclosed together with the methods of extraction of said information. The visualizing systems offer high spatial resolution and/or high magnetic field resolution combined with fast sampling rates and the capability of performing large-area imaging. The applications of such systems include nondestructive testing and damage assessment in metal structures via magnetic materials or induced currents, integrated circuit testing and quality control, general magnetic material and thin film research, permanent magnet quality control, superconductor research and many others.

Abstract: A plate having leaky waveguides defined therethrough can be used for retroreflection suppression and/or light diffusing/optical isolation. Such designs can exhibit good performance over a wider range of wavelengths and angles of the incident light than current art optical components.

Abstract: An optical sensor diagnostic system utilizes a tunable Vertical Cavity Surface Emitting Laser (VCSEL) that incorporates an integrated MEMS tuning mechanism provides variable wavelength light into an optical fiber with improved wavelength scanning speed and greater simplicity of construction. Sensors, such as Bragg gratings, are disposed along the fiber in the light path. Each sensor reflects or transmits light exhibiting a characteristic amplitude and/or phase feature with respect to wavelength, the wavelength position of which is affected by an environmental stimulus imposed thereon. The light reflected or transmitted through each sensor is mixed with light passed through an optical reference path and then converted to an electrical signal by a simple detector and monitored by ciruitry that applies signal processing to the detected power spectral distribution, by this means providing output signals indicative of the environmental stimulus on each sensor.

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: An optical sensor diagnostic system uses a tunable Vertical Cavity Surface Emitting Laser (VCSEL) that incorporates an integrated MEMS tuning mechanism. The system provide variable wavelength light into an optical fiber with improved wavelength scanning speed and greater simplicity of construction. Sensors, such as Bragg gratings, are disposed along the fiber in the light path. Each sensor reflects or transmits light exhibiting a characteristic amplitude feature with respect to wavelength, the wavelength position of which is affected by an environmental stimulus imposed thereon. The reflected light is converted to an electrical signal by a simple detector and monitored by circuitry that detects changes. The system provides output signals indicative of the environmental stimulus for each sensor.

Abstract: Magnetic field and/or electrical current imaging systems utilizing magneto-optical indicator films (MOIF) based on magneto-optical material with in-plane single easy axis type of magnetic anisotropy provide improved magnetic field resolution and dynamic range with the use of specific illumination conditions. Methods that provide the two-dimensional distribution of the external magnetic field vectors are disclosed together with the methods of extraction of said information. The visualizing systems offer high spatial resolution and/or high magnetic field resolution combined with fast sampling rates and the capability of performing large-area imaging. The applications of such systems include nondestructive testing and damage assessment in metal structures via magnetic materials or induced currents, integrated circuit testing and quality control, general magnetic material and thin film research, permanent magnet quality control, superconductor research and many others.

Abstract: An optical sensor diagnostic system uses a tunable Vertical Cavity Surface Emitting Laser (VCSEL) that incorporates an integrated MEMS tuning mechanism. The system provides variable wavelength light into an optical fiber with improved wavelength scanning speed and greater simplicity of construction. Sensors, such as Bragg gratings, are disposed along the fiber in the light path. Each sensor reflects or transmits light exhibiting a characteristic amplitude feature with respect to wavelength, the wavelength position of which is affected by an environmental stimulus imposed thereon. The reflected light is converted to an electrical signal by a simple detector and monitored by circuitry that detects changes. The system provides output signals indicative of the environmental stimulus for each sensor.

Abstract: An optical sensor diagnostic system utilizes a tunable Vertical Cavity Surface Emitting Laser (VCSEL) that incorporates an integrated MEMS tuning mechanism provides variable wavelength light into an optical fiber with improved wavelength scanning speed and greater simplicity of construction. Sensors, such as Bragg gratings, are disposed along the fiber in the light path. Each sensor reflects or transmits light exhibiting a characteristic amplitude and/or phase feature with respect to wavelength, the wavelength position of which is affected by an environmental stimulus imposed thereon. The light reflected or transmitted through each sensor is mixed with light passed through an optical reference path and then converted to an electrical signal by a simple detector and monitored by circuitry that applies signal processing to the detected power spectral distribution, by this means providing output signals indicative of the environmental stimulus on each sensor.

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: The UV, deep UV and/or far UV (ultraviolet) filter transmission spectrum of an MPSi spectral filter is optimized by introducing at least one layer of substantially transparent dielectric material on the pore walls. Such a layer will modify strongly the spectral dependences of the leaky waveguide loss coefficients through constructive and/or destructive interference of the leaky waveguide mode inside the layer. Increased blocking of unwanted wavelengths is obtained by applying a metal layer to one or both of the principal surfaces of the filter normal to the pore directions. The resulting filters are stable, do not degrade over time and exposure to UV irradiation, and offer superior transmittance for use as bandpass filters. Such filters are useful for a wide variety of applications including but not limited to spectroscopy and biomedical analysis systems.

Abstract: The UV, deep UV and/or far UV (ultraviolet) filter transmission spectrum of an MPSi spectral filter is optimized by introducing at least one layer of substantially transparent dielectric material on the pore walls. Such a layer will modify strongly the spectral dependences of the leaky waveguide loss coefficients through constructive and/or destructive interference of the leaky waveguide mode inside the layer. Increased blocking of unwanted wavelengths is obtained by applying a metal layer to one or both of the principal surfaces of the filter normal to the pore directions. The resulting filters are stable, do not degrade over time and exposure to UV irradiation, and offer superior transmittance for use as bandpass filters. Such filters are useful for a wide variety of applications including but not limited to spectroscopy and biomedical analysis systems.