Abstract: Temperature measurements of sheet material such as paper can be obtained directly from an analysis of the absorption spectrum of water in the infrared region. The technique is based in part on the recognition that the central wavelength position of a selected moisture peak is dependent upon the sheet temperature; the wavelength position also has a known temperature sensitivity. Thus, once the wavelength position of this moisture peak is ascertained, the moisture temperature of the product being monitored can be calculated. The position of the moisture peak is preferably obtained from the derivative of the peak. By measuring the size of the infrared absorption and the wavelength position of the absorption peak, both the moisture content and the moisture temperature of the sheet material can be determined. The data is used for process control. Tunable laser diodes are particularly suited as the source of infrared radiation for the temperature sensors.

Abstract: A compact, long lasting sensor for measuring components such as moisture in moving sheets including paper in a papermaking apparatus employs light sources that produce radiation within defined wavelength regions of interest and the light sources are modulated at high frequencies using non-mechanical techniques. A single detector with various radiation sources can measure at all frequencies while keeping information separated. Superluminescent light emitting diode or laser diode light sources can be directly electrically modulates for improved noise rejection. These higher power and bright light sources afford excellent fiber optic launch efficiency and permits the sensor to be scanned at much faster rates over the paper being monitored.

Abstract: An efficient and versatile spectrometric sensor can be configured with an acousto-optic tunable filter. With this diverse spectral filter, the central wavelength and bandwidth of the filter can be quickly tuned to the desired wavelength.

Abstract: Techniques for non-contacting thickness or caliper measurements of moving webs or sheets employ a sensor device that includes a first sensor head and a second sensor head that are spaced apart to define a path through which the moving web travels. The sensor device projects a laser generated, multiple points pattern onto the upper surface of the moving web. Pattern recognition algorithm analysis of the pattern identifies the orientation, e.g., tilt, of the moving web. The device further measures the film tilt, the distance between the first sensor head and the first web surface, the distance between the second sensor head and the second web surface, and the distance between the two sensor heads to provide a highly accurate on-line thickness measurement of the moving web.

Abstract: Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100 W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.

Abstract: A scanning system includes a cable take-up mechanism that uses a series of pulleys that determine the bend diameters of a scanning system. The mechanism is particularly suited for a spectrometric, e.g., infrared, scanning system where moving scanner or sensor head essentially houses only the optical elements while essentially of all the other electronic and optical components associated with the measurement are housed in an easily accessible compartment that is remote from the moving scanner head. Light is transmitted through optical fiber cables. The cable take-up mechanism maintains the fiber optic cable at essentially constant total bend length and bend diameter thereby minimizing any dynamic changes to spectral bend losses as the optical head is scanned. The light weight construction of the sensor head further reduces vibrations associated with the moving scanner head.

Abstract: Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.

Abstract: Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.

Abstract: Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.