Abstract:
An optical pressure sensor is disclosed having a pressure sensing optical cavity. A temperature sensing optical cavity at the sensing head is used by an interrogator to correct a pressure signal for effects of temperature. The optical cavities may be, for example, Fabry Perot cavities in the sensor head.
Abstract:
An observation apparatus (100) includes an observing optical system (101) capable of obtaining an image of a measurement target present in a gap included in a device (1). One end of the gap included in the device (1) is wider than the other end thereof, and upon light beam irradiation to the device (1), an interference fringe appears in the gap. The observing optical system (101) irradiates the gap included in the device (1) with a plurality of light beams having different wavelengths to cause a plurality of interference fringes to appear in the gap. Then the observing optical system (101) obtains an image of the plurality of interference fringes.
Abstract:
A cylindrical package includes a cylindrical housing; a pedestal at a bottom of a cylindrical space surrounded by the cylindrical housing; an optical splitter in the cylindrical space and over the pedestal; a first photodetector in the cylindrical space and over the pedestal, wherein the first photodetector is configured to be optically coupled to the optical splitter; and a second photodetector in the cylindrical space and over the pedestal, wherein the second photodetector is configured to be optically coupled to the optical splitter.
Abstract:
A method and apparatus for producing with a gas discharge laser an output laser beam comprising output laser light pulses, for delivery as a light source to a utilizing tool is disclosed which may comprise a beam path and a beam homogenizer in the beam path. The beam homogenizer may comprise at least one beam image inverter or spatial rotator, which may comprise a spatial coherency cell position shifter. The homogenizer may comprise a delay path which is longer than, but approximately the same delay as the temporal coherence length of the source beam. The homogenizer may comprise a pair of conjoined dove prisms having a partially reflective coating at the conjoined surfaces of each, a right triangle prism comprising a hypotenuse face facing the source beam and fully reflective adjoining side faces or an isosceles triangle prism having a face facing the source beam and fully reflective adjoining side faces or combinations of these, which may serve as a source beam multiple alternating inverted image creating mechanism. The beam path may be part of a bandwidth measuring the bandwidths of an output laser beam comprising output laser light in the range of below 500 femtometers at accuracies within tens of femtometers. The homogenizer may comprise a rotating diffuser which may be a ground glass diffuser which may also be etched. The wavemeter may also comprise a collimator in the beam path collimating the diffused light; a confocal etalon creating an output based upon the collimated light entering the confocal etalon; and a detector detecting the output of the confocal etalon and may also comprise a scanning mechanism scanning the angle of incidence of the collimated light entering the confocal etalon which may scan the collimated light across the confocal etalon or scan the etalon across the collimated light, and may comprise an acousto-optical scanner. The confocal etalon may have a free spectral range approximately equal to the E95 width of the beam being measured. The detector may comprise a photomultiplier detecting an intensity pattern of the output of the confocal etalon.
Abstract:
An optical component in the form of a right angled triangular prism having a first side, a second side orthogonal to the first side, and a third side generally inclined to the first and second sides to reflect optical radiation incoming from the first side towards the second side. The first and second sides have semi-reflecting surfaces acting as etalon surfaces providing an interferometric pattern. The optical transmittance between the first and the second sides is wavelength dependent and the radiation exiting the second side of the component is rotated 90 degrees to the radiation entering the first side.
Abstract:
A wavelength stabilizing apparatus utilized in an optical communication system for controlling a light wave output from a tunable optical component is disclosed. The wavelength stabilizing apparatus includes a coarse-tuning element, a fine-tuning element, and a servo element. When the wavelength stabilizing apparatus is used, the light wave output from the tunable optical component is directed into the coarse-tuning element and the fine-tuning element, respectively, and then transformed into electric signals to be received by the servo element. Particularly, the electric signals from the coarse-tuning element are served as basis for coarse-tuning and channel recognition of the light wave output from the tunable optical component while the electric signals from the fine-tuning element are served for fine-tuning and servo control of the light wave output from the tunable optical component. These electric signals are also processed with a logical operation to obtain a control signal for controlling the tunable optical component.
Abstract:
An optical component in the form of a right angled triangular prism having a first side, a second side orthogonal to the first side, and a third side generally inclined to the first and second sides to reflect optical radiation incoming from the first sided towards the second side. The first and second sides have semi-reflecting surfaces acting as etalon surfaces providing an interferometric pattern. The optical transmittance between the first and the second sides is wavelength dependent and the radiation exiting the second side of the component is rotated 90 degrees to the radiation entering the first side.
Abstract:
A multiple phase wavelength locker employs an etalon with multiple steps, the steps providing optical cavities having different optical lengths for use with multiple photodetectors, such that a resonance position of each etalon step is offset by a fraction of a resonance period. The stepped etalon can be employed to track the exact wavelength of a laser in a wavelength division multiplexing (WDM) system.
Abstract:
A data distribution system (10) including an information card (12) and a reader (14). The information card (12) includes visible indicia (20) on its front and stripe zones (34) and a ring zone (36) on its back. The zones (34, 36) are suitable for magnetically recording data, and optional data identifiers. The reader (14) may be a linear reader (14a) or a rotary reader (14b), and optionally may act automatically in response to reading a data identifier. If the reader (14) is a rotary reader (14b) the information card (12) may be loaded into a cartridge (16) which is loaded into the rotary reader (14b).
Abstract:
A compact wavelength monitoring and control assembly for a narrow band (i.e., laser) source is provided, comprising two narrow bandpass, wavelength selective transmission filter elements of Fabry-Perot structure through which two separate collimated beams from a laser source are directed onto two photodetectors. The spacing of the multiple transmission maxima for one etalon is chosen to match that of the desired set of frequencies to be used for locking purposes. The spacing of the transmission maxima for the second etalon is used, in combination with a dielectric filter, to generate a wavelength fiducial to denote an absolute frequency. The spacing of the second etalon is chosen to be much wider than the frequency grid etalon. A control circuit processes the simultaneously acquired signals from the two detectors as the laser wavelength is varied. The device functions as an optical wavelength discriminator in which the detectors convert optical energy to current (or voltage) for a feedback loop for controlling the laser source. Any one of a large number of discrete, predetermined wavelengths may be chosen for locking using the same device. The system is compact and may be packaged within the same temperature controlled laser assembly for maximum performance and minimum circuit board space requirements.