Abstract: In a tapping mode Atomic Force Microscope (AFM) system, a probe is excited at an excitation frequency other than the probe's first natural frequency to produce a response signal manifesting a grazing bifurcation between “non-collision” and “collision” states of the AFM system, so that an additional characteristic frequency component is generated in the “collision” state. The magnitude of the additional characteristic frequency component is monitored in real time, and the probe-sample separation is adjusted to maintain the monitored magnitude at an optimal value to operate the AFM system at near-grazing conditions.

Abstract: In a tapping mode Atomic Force Microscope (AFM) system, a probe is excited at an excitation frequency other than the probe's first natural frequency to produce a response signal manifesting a grazing bifurcation between “non-collision” and “collision” states of the AFM system, so that an additional characteristic frequency component is generated in the “collision” state. The magnitude of the additional characteristic frequency component is monitored in real time, and the probe-sample separation is adjusted to maintain the monitored magnitude at an optimal value to operate the AFM system at near-grazing conditions.

Abstract: A micro-optical fiber tip based sensor system for pressure, acceleration, and pressure gradient measurements in a wide bandwidth, the design of which allows for multiplexity of the input side of the system is based on micro-electromechanical fabrication techniques. The optical portion of the system is based on low coherence fiber-optic interferometry techniques which has a sensor Fabry-Perot interferometer and a read-out interferometer combination that allows a high dynamic range and low sensitivity to the wavelength fluctuation of the light source. A phase modulation and demodulation scheme takes advantage of the Integrated Optical Circuit phase modulator and multi-step phase-stepping algorithm for providing high frequency and real time phase signal demodulation. The system includes fiber tip based Fabry-Perot sensors each of which has a diaphragm that is used as a transducer.

Abstract: A fiber optic sensor system for pressure measurements where the design permits multiplexity on the input side of the system and the optical part of the system, which has a sensor Fabry-Perot interferometer and a read-out interferometer, is based on low coherence fiber-optic interferometry techniques. This permits a high dynamic range and low sensitivity to the wavelength fluctuation of the light source as well as to the optical intensity fluctuations. The system includes fiber tip based Fabry-Perot sensors, where each sensor includes a diaphragm as the transducer. A combined pressure gradient sensor, air particle velocity sensor, as well as acoustic intensity sensor is built based on the fiber tip based Fabry-Perot sensors.

Abstract: A micro-optical fiber tip based sensor system for pressure, acceleration, and pressure gradient measurements in a wide bandwidth, the design of which allows for multiplexity of the input side of the system is based on micro-electromechanical fabrication techniques. The optical portion of the system is based on low coherence fiber-optic interferometry techniques which has a sensor Fabry-Perot interferometer and a read-out interferometer combination that allows a high dynamic range and low sensitivity to the wavelength fluctuation of the light source. A phase modulation and demodulation scheme takes advantage of the Integrated Optical Circuit phase modulator and multi-step phase-stepping algorithm for providing high frequency and real time phase signal demodulation. The system includes fiber tip based Fabry-Perot sensors each of which has a diaphragm that is used as a transducer.

Abstract: A fiber optic sensor system for pressure measurements where the design permits multiplexity on the input side of the system and the optical part of the system, which has a sensor Fabry-Perot interferometer and a read-out interferometer, is based on low coherence fiber-optic interferometry techniques. This permits a high dynamic range and low sensitivity to the wavelength fluctuation of the light source as well as to the optical intensity fluctuations. The system includes fiber tip based Fabry-Perot sensors, where each sensor includes a diaphragm as the transducer. A combined pressure gradient sensor, air particle velocity sensor, as well as acoustic intensity sensor is built based on the fiber tip based Fabry-Perot sensors.

Abstract: A fiber optic sensor system for acoustic measurements over a 6 kHz bandwidth, the design of which allows for multiplexity of the input side of the system, and where the optical part of the system is based on low coherence fiber-optic interferometry techniques which has a sensor Fabry-Perot interferometer and a read-out interferometer as well, that allows a high dynamic range and low sensitivity to the wavelength fluctuation of the light source, as well as the optical intensity fluctuations. A phase modulation and demodulation scheme takes advantage of the Integrated Optical Circuit phase modulator and multi-step phase-stepping algorithm for providing for high frequency and real time phase signal demodulation. The system includes fiber tip based Fabry-Perot sensors which have a diaphragm, which is used as the transducer. Pressure microphone, velocity sensor, as well as accelerometer, are built based on the fiber tip based Fabry-Perot sensors.

Abstract: A fiber optic sensor system for acoustic measurements over a 6 kHz bandwidth, the design of which allows for multiplexity of the input side of the system, and where the optical part of the system is based on low coherence fiber-optic interferometry techniques which has a sensor Fabry-Perot interferometer and a read-out interferometer as well, that allows a high dynamic range and low sensitivity to the wavelength fluctuation of the light source, as well as the optical intensity fluctuations. A phase modulation and demodulation scheme takes advantage of the Integrated Optical Circuit phase modulator and multi-step phase-stepping algorithm for providing for high frequency and real time phase signal demodulation. The system includes fiber tip based Fabry-Perot sensors which have a diaphragm, which is used as the transducer. Pressure microphone, velocity sensor, as well as accelerometer, are built based on the fiber tip based Fabry-Perot sensors.