Abstract: Charge transfer is provided to or from an electrically isolated test body by AC modulation of the photoelectric effect. More specifically, a reference body is disposed near the test body without physical contact between the reference and test bodies. Facing surfaces of the reference and test bodies are illuminated by optical radiation having a sufficiently short wavelength that charged particles are emitted from the reference and test bodies. An electrical bias is established between the reference body and the test body. Both the optical radiation and the electrical bias are modulated at the same frequency. A magnitude and direction of a charge transfer rate between the reference and test bodies is set by selecting a phase relation between the optical radiation and the electrical bias.

Abstract: An angular magnification effect of diffraction is exploited to provide improved sensing and scanning. This effect is most pronounced for a normal or near-normal incidence angle in combination with a grazing diffraction angle, so such configurations are preferred. Angular sensitivity can be further enhanced because the width of the diffracted beam can be substantially less than the width of the incident beam. Normal incidence configurations with two symmetric diffracted beams are preferred, since rotation and vertical displacement can be readily distinguished. Increased sensitivity to vertical displacement can be provided by incorporating an interferometer into the measurement system. Quad cell detectors can be employed to provide sensitivity to rotation about the grating surface normal. A 2-D grating can be employed to provide sensitivity to angular displacements in two different planes (e.g., pitch and yaw).

Abstract: Measurement of a distance change between a reference surface and a target is provided. A substrate has a first surface facing the target and including a grating. The grating and target combine to form an optical interferometer responsive to changes in distance between the grating and the target. A second surface of the substrate coincides with the reference surface and faces away from the target. Thickness information pertaining to the substrate is combined with results from the optical interferometer to provide a measurement of distance change between reference surface and target. The substrate is preferably a rigid material having picometer level dimensional stability.

Abstract: Charge transfer is provided to or from an electrically isolated test body by AC modulation of the photoelectric effect. More specifically, a reference body is disposed near the test body without physical contact between the reference and test bodies. Facing surfaces of the reference and test bodies are illuminated by optical radiation having a sufficiently short wavelength that charged particles are emitted from the reference and test bodies. An electrical bias is established between the reference body and the test body. Both the optical radiation and the electrical bias are modulated at the same frequency. A magnitude and direction of a charge transfer rate between the reference and test bodies is set by selecting a phase relation between the optical radiation and the electrical bias.

Abstract: An angular magnification effect of diffraction is exploited to provide improved sensing and scanning. This effect is most pronounced for a normal or near-normal incidence angle in combination with a grazing diffraction angle, so such configurations are preferred. Angular sensitivity can be further enhanced because the width of the diffracted beam can be substantially less than the width of the incident beam. Normal incidence configurations with two symmetric diffracted beams are preferred, since rotation and vertical displacement can be readily distinguished. Increased sensitivity to vertical displacement can be provided by incorporating an interferometer into the measurement system. Quad cell detectors can be employed to provide sensitivity to rotation about the grating surface normal. A 2-D grating can be employed to provide sensitivity to angular displacements in two different planes (e.g., pitch and yaw).

Abstract: Measurement of a distance change between a reference surface and a target is provided. A substrate has a first surface facing the target and including a grating. The grating and target combine to form an optical interferometer responsive to changes in distance between the grating and the target. A second surface of the substrate coincides with the reference surface and faces away from the target. Thickness information pertaining to the substrate is combined with results from the optical interferometer to provide a measurement of distance change between reference surface and target. The substrate is preferably a rigid material having picometer level dimensional stability.

Abstract: An apparatus comprising an acoustically resonant ultrasound launcher is provided for cleaning of optical fiber connectors and other optical fiber parts. The resonant ultrasound launcher is designed to transfer and to focus ultrasonic energy from an ultrasound transducer to a relatively small target area with high intensity. Specially designed fluid flow channels allow this apparatus to efficiently clean optical fiber connectors with an exposed end surface or with an end surface concealed in a connector adapter. Circuitry is provided to automatically track the frequency to enhance the ultrasound generation. Another circuitry is provided to program the sequence of the cleaning process, including washing, rinsing and drying.

Abstract: An apparatus comprising an acoustically resonant ultrasound launcher is provided for cleaning of optical fiber connectors and other optical fiber parts. The resonant ultrasound launcher is designed to transfer and to focus ultrasonic energy from an ultrasound transducer to a relatively small target area with high intensity. Specially designed fluid flow channels allow this apparatus to efficiently clean optical fiber connectors with an exposed end surface or with an end surface concealed in a connector adapter. Circuitry is provided to automatically track the frequency to enhance the ultrasound generation. Another circuitry is provided to program the sequence of the cleaning process, including washing, rinsing and drying.