Abstract: A method for balancing a color wheel. The rotational unbalance vector of a driving motor is measured, including its unbalance amount and direction. The unbalance of a color wheel is adjusted to make its unbalance amount to be the same of the driving motor. The color wheel is connected to the driving motor so that the unbalance direction thereof is opposite to each other to reach an expected balance. The color wheel structure includes a set of color filter and a ring, before starting the assembly, adjusting the unbalance vector of the ring and motor shaft first, and then to assemble it and make the unbalance vectors opposite.

Abstract: An optical amplifier includes an optical fiber having a core doped with transition metal ions, and at least one glass cladding enclosing the core. By using the fiber, the optical amplifier of the invention has a gain bandwidth of more than 300 nm including 1300-1600 nm band in low-loss optical communication.

Abstract: A fabrication method for hollow integration rod suitable for high temperature operation, comprising the steps: (a) pre-fixing a set of mirrors to be a hollow integration rod by a light curable adhesive (such as UV curable adhesive); and (b) fixing those mirrors permanently by an inorganic adhesive. Wherein the mirrors can be a High Reflective Mirror with dielectric thin films, or it could be a High Reflective Mirror made of metallic thin film and coating a dielectric thin films by deposition for enhancing the reflection and protection purpose; for a all dielectric film, since there are multi-layer of thin dielectric films been deposited thereon, to prevent the warpage or distortion due to film stress in deposition process, several layers of thin film of silicon oxide SiOx can be pre-deposited on the backside of the mirror to balance.

Abstract: An integration rod structure for a digital projector comprising a length of hollow integration rod and a length of solid integration rod, reflecting an incoming light beam to pass through to acquire a homogeneous light beam in a shorter length than normal solid integration rod with lower energy loss during the refraction. Preferably, the adhesive for bonding the hollow integration rod and the solid integration rod is mixed with small particles (for instance, a plurality of small balls in an average diameter 1 to 1000 ?m), to make most of the bonding interfaces not to direct contact to each other, to prevent lower the total reflection effect within the solid integration rod.

Abstract: A method for balancing a color wheel comprising: step (a), measuring the rotational deviation vector of a driving motor, including its deviation amount and direction; step (b), adjusting the deviation of a color wheel to make its deviation amount to be the same of the driving motor; and step (c), connecting the color wheel to the driving motor and let the deviation direction thereof to be opposite to each other to reach an expected balance. According to the present invention, an embodiment of the color wheel structure may includes a set of color filter and a ring, before to start the assembly, adjusting the deviation vector of the ring and motor shaft first, and then to assemble it and make the deviation vectors oppositely.