In-fiber linear polarizer based on UV-inscribed 45° tilted grating in polarization maintaining fiber

We report an in-fiber linear polarizer structured by UV-inscribing a 45° tilted fiber grating (TFG) into polarization maintaining (PM) fiber along its principal axis. The polarization extinction ratio (PER) achieved by a 48 mm long 45° TFG has reached 46 dB at 1550 nm and the overall PER is >40 dB over a 50 nm wavelength range. Such 45° TFG based polarizers have many advantages over conventional products, including low loss, low cost, simple fabrication process, and no physical modification to the fiber, thus offering high stability and capable of handling high power

Healthsouth Corporation: The First Case Against A Company Under The Sarbanes-Oxley Act

HealthSouth Corporation, one of the nation’s largest healthcare providers, was the first company charged under the provisions of the Sarbanes-Oxley Act.  HealthSouth’s CEO, Richard Scrushy, and 16 of its executives were indicted for allegedly using a sophisticated scheme to overstate the company’s earnings by as much as $2.7 billion between 1986 and 2002.  Fifteen of the sixteen indicted executives pleaded guilty and another was convicted by jurors.  After five months of court hearing, Scrushy was acquitted of all criminal charges.  However, he remains a defendant in 40 cases filed by former HealthSouth investors and creditors.   This case is based on court materials and other publicly available information and has been used in several undergraduate and MBA courses.  The case and the accompanying teaching notes have proven to be an effective tool in teaching students the Sarbanes-Oxley Act and in helping students become more ethically conscious

Refractometer based on fiber Bragg grating Fabry-Pérot cavity embedded with a narrow microchannel

We report on inscription of microchannels of different widths in optical fiber using femtosecond (fs) laser inscription assisted chemical etching and the narrowest channel has been created with a width down to only 1.2µm. Microchannels with 5µm and 35µm widths were fabricated together with Fabry-Pérot (FP) cavities formed by UV laser written fiber Bragg gratings (FBGs), creating high function and linear response refractometers. The device with a 5µm microchannel has exhibited a refractive index (RI) detection range up to 1.7, significantly higher than all fiber grating RI sensors. In addition, the microchannel FBG FP structures have been theoretically simulated showing excellent agreement with experimental measured characteristics

Novel fiber Bragg grating sensor implemented in a polymer-core/silica- cladding hybrid optical fiber

A polymer-core/silica-cladding hybrid optical fiber is implemented by filling a capillary with UV-curable epoxy and a following UV-laser scanning exposure. A fiber Bragg grating is successfully inscribed in parallel using a phase mask. The experimental results show a reduced thermal response for the FBG and a theoretical analysis for such a hybrid optical fiber is performed which corroborates existing of a turning temperature for minimized thermal response