Abstract: A multilayered optical security device has a resonant waveguide grating (RWG) layer on an under layer having a hologram. The RWG layer has plural RWGs for generating one or more patterns. Each RWG has first and second RWG portions, with diffraction gratings of different grating periods, for light coupling-in and coupling-out, respectively. Using the RWGs minimizes interference to a holographic image generated by the under layer. This advantage is especially useful when the holographic image carries digital data such as in digital holographic encryption where an encrypted hologram is used in the under layer. The digital data may contain biometric information such as a fingerprint. In each RWG portion of an individual RWG, scattering elements in a grating are curved to thereby enhance an angular tolerance in azimuthal angle during observing the patterns by an observer while the individual RWG is still selective in elevation angle.

Abstract: Polarization-independent focusing is advantageously achieved by a multifocal system having a polarization beam splitter (PBS) to split an unpolarized light beam into two orthogonally linearly-polarized (LP) light beams. The two LP light beams are reflected by mirrors to travel in opposite directions and enter into a variable-focusing module at two ends thereof, respectively. The module includes waveplates to convert the LP light beams into two circularly-polarized (CP) light beams at both ends of an optical assembly. The optical assembly is formed with a stack of birefringent optical elements including at least one geometric phase lens and one polarization selector that may be electrically modulated to select the optical power in focusing the two CP light beams. Followed by the waveplates converting two focused CP light beams to two focused LP light beams and upon mirror reflection, the beams are finally recombined by the PBS to form one focused light beam.

Abstract: A multilayered optical security device has a resonant waveguide grating (RWG) layer on an under layer having a hologram. The RWG layer has plural RWGs for generating one or more patterns. Each RWG has first and second RWG portions, with diffraction gratings of different grating periods, for light coupling-in and coupling-out, respectively. Using the RWGs minimizes interference to a holographic image generated by the under layer. This advantage is especially useful when the holographic image carries digital data such as in digital holographic encryption where an encrypted hologram is used in the under layer. The digital data may contain biometric information such as a fingerprint. In each RWG portion of an individual RWG, scattering elements in a grating are curved to thereby enhance an angular tolerance in azimuthal angle during observing the patterns by an observer while the individual RWG is still selective in elevation angle.

Abstract: Polarization-independent focusing is advantageously achieved by a multifocal system having a polarization beam splitter (PBS) to split an unpolarized light beam into two orthogonally linearly-polarized (LP) light beams. The two LP light beams are reflected by mirrors to travel in opposite directions and enter into a variable-focusing module at two ends thereof, respectively. The module includes waveplates to convert the LP light beams into two circularly-polarized (CP) light beams at both ends of an optical assembly. The optical assembly is formed with a stack of birefringent optical elements including at least one geometric phase lens and one polarization selector that may be electrically modulated to select the optical power in focusing the two CP light beams. Followed by the waveplates converting two focused CP light beams to two focused LP light beams and upon mirror reflection, the beams are finally recombined by the PBS to form one focused light beam.

Abstract: A diaper includes a medical pad including a piece of substrate with a major surface and an electric circuit on the major surface, a sensor connected with the electric circuit for measuring the electrical resistance of the electric circuit, and a wireless data transceiver or a radio frequency identification (RFID) tag electrically connected with the sensor for receiving results of the measuring from the sensor for subsequent transmission. The system carries out real time self-calibration to adaptively monitor the condition of the medical pad even in the face of changing environment and changing material properties.

Abstract: A diaper includes a medical pad including a piece of substrate with a major surface and an electric circuit on the major surface, a sensor connected with the electric circuit for measuring the electrical resistance of the electric circuit, and a wireless data transceiver or a radio frequency identification (RFID) tag electrically connected with the sensor for receiving results of the measuring from the sensor for subsequent transmission. The system carries out real time self-calibration to adaptively monitor the condition of the medical pad even in the face of changing environment and changing material properties.

Abstract: A medical pad includes a piece of substrate with a major surface and an electric circuit on the major surface, a sensor connected with the electric circuit for measuring the electrical resistance of the electric circuit, and a wireless data transceiver or a radio frequency identification (RFID) tag electrically connected with the sensor for receiving results of the measuring from the sensor for subsequent transmission. The system carries out real time self-calibration to adaptively monitor the condition of a medical pad even in the face of changing environment and changing material properties.

Abstract: A medical pad includes a piece of substrate with a major surface and an electric circuit on the major surface, a sensor connected with the electric circuit for measuring the electrical resistance of the electric circuit, and a wireless data transceiver or a radio frequency identification (RFID) tag electrically connected with the sensor for receiving results of the measuring from the sensor for subsequent transmission. The system carries out real time self-calibration to adaptively monitor the condition of a medical pad even in the face of changing environment and changing material properties.

Abstract: An ultra thin antenna (100, 200) is disclosed as having a rectangular path (102, 202) and at least one extender piece (104, 108, 110, 212) for extension of radio frequency (RF) energy out of the rectangular path (102, 202).

Abstract: A method for providing a visual representation pertaining to a resolution of at least one scanned image segment obtained from a portable scanner is disclosed. The method includes associating the scanned image segment with positional coordinates relative to an image on a scanned medium. The method also includes determining the resolution of the scanned image segment and assigning the scanned image segment to a resolution category associated with the resolution. The method also includes displaying the image segment in a format associated with the resolution category, at a location corresponding to the location of the image segment relative to the image on the scanned medium.