Abstract: The present invention generally concerns the use of Bragg optical fibers in chirped pulse amplification systems for the production of high-pulse-energy ultrashort optical pulses. A gas-core Bragg optical fiber waveguide can be advantageously used in such systems to stretch the duration of pulses so that they can be amplified, and/or Bragg fibers can be used to compress optical signals into much shorter duration pulses after they have been amplified. Bragg fibers can also function as near-zero-dispersion delay lines in amplifier sections.

Abstract: Our wafer scale processing techniques produce chip-laser-diodes with a diffraction grating (78) that redirects output light out the top (88) and/or bottom surfaces. Generally, a diffraction grating (78) and integrated lens-grating (78) are used herein to couple light from the chip to an output fiber (74), and the lens-grating (78) is spaced from the diffraction grating (76). Preferably the diffraction grating (76) and integrated lens grating (78) are also used to couple light from the output fiber (74) back to the active region of the chip. The integrated lens-grating (78) can be in a coupling block (82). The use of a coupling block (82) can eliminate “facet-type damage”. A coupling block (82) is generally used herein to couple light from the chip to an output fiber (74), and preferably to couple feedback reflected from the fiber (74) back to the chip.

Abstract: Wafer scale processing techniques produce chip-laser-diodes with an active region (62) and a diffraction grating (76) that redirects output light out the top and/or bottom surfaces. The diffraction grating (76) redirects a novel feedback from the optical output (e.g., fiber (74)) to produce lasing that self-aligns itself to the fiber input, reducing assembly costs. Preferably, a diffraction grating (76) and integrated lens-grating are used herein to couple light from the chip to an output fiber (74), and the lens-grating is spaced from the diffraction grating (76). Combination grating and additional gratings and/or integrated lenses on the top or bottom of the diode can also be made utilizing wafer scale processes.

Abstract: The eye-tracking system is based on the reflection of four light emitting diodes (LED)s at the cornea of user's eve. The LEDs emit infrared light at 900 nanometers and the virtual images formed behind the cornea as well as a near infrared image of the pupil are displayed on a charged couple device (CCD) sensor. The optical system used to display virtual environments is also used to conjugate the virtual images of the LEDs to the CCD sensor. This optimizes the integration of eyetracking system into the head mounted device (HMD). The four LEDs are laid out around the imaging (optical) system and their beam (rays) impinge directly on the eye by reflection on the hot mirror. Then the light reflected by the cornea is reflected again by the hot mirror, goes through the optical system and the cold mirror to be imaged on the sensor.