Abstract:
A VCSEL includes a substrate having a partially removed portion; a metal-assisted DBR having a metal layer and a first mirror stack, wherein the metal layer is located at the partially removed portion of the substrate; an active region having a plurality of quantum wells over the metal-assisted DBR; and a second mirror stack over the active region, wherein a number of alternating layers of the first mirror stack is substantially smaller than a number typically required for a VCSEL without the integrated metal reflector. Such a metal-assisted DBR is especially useful for a long-wavelength VCSEL on a InP substrate or a red-color VCSEL on a GaAs substrate.
Abstract:
A vertical cavity surface emitting laser (VCSEL) structure includes a bottom distributed Bragg reflector (DBR) arranged over a substrate; a metal layer interposed between the bottom DBR and the substrate, wherein the metal layer and bottom DBR form a composite mirror structure. A patterned dielectric layer may be interposed between the metal layer and the bottom DBR to reduce a deleterious chemical reaction between the metal layer and the bottom DBR. The metal layer directly contacts a portion of the bottom DBR to enhance the electrical and thermal conductivity of the
Abstract:
A current confinement layer of a VCSEL is formed by adjusting flow rates of In-, Al-, and As-containing precursors introduced within a deposition chamber. By maintaining a low ratio between the flow rate of the As-containing precursors and the total flow rate of In- and Al-containing precursors (e.g., less than 25, 10, 5, or 1), a current confinement layer, lattice matched to InP and having an enhanced oxidation rate, may be formed.
Abstract:
A vertical cavity surface emitting laser with a mode-selective mirror. A filter is formed on the top DBR stack of a VCSEL. The filter includes semiconductor layers that are etch stops for immediately superior layers. The filter is selectively etched to create a first region that is phase matched to the top DBR stack and a second region that is phase mismatched to the top DBR stack. The second region inhibits undesired modes and provides additional absorption for the undesired modes. The first region is formed using a wet-etch process whose etch depth is controlled because the semiconductor layers are etch stops for immediately superior layers.
Abstract:
A vertical cavity surface emitting laser (VCSEL) includes independently definable current and optical confinement structures that provide unique forms of drive current and transverse mode confinement, respectively. The optical guide may be formed from an upper distributed Bragg reflector (DBR), as an etched mesa structure and/or as an intracavity optical guide. The current guide may include an ion-implanted region within the upper DBR. A dielectric structure is formed over the upper DBR and surrounds the optical guide.
Abstract:
A light guide plate and a liquid crystal display device having the same. The light guide plate is disposed upstream of a liquid crystal panel to refract light supplied through an edge thereof, toward the liquid crystal panel. In the light guide plate, a plate body is disposed at a side of a light source for supplying light when a supply voltage is applied. A plurality of pyramidal diffusing elements are arrayed in a predetermined pattern on a surface of the plate body. Each of the diffusing elements is rotated clockwise or counterclockwise about an axis extending through a vertex of the diffusing element perpendicularly to the surface of the plate body so that an edge of the diffusing element facing a reference line connecting a central point of the light source to a central point of the plate body is angled 10° to 35° about the reference line.
Abstract:
A digital broadcast transmitting/receiving system and a method for processing data are disclosed. The method for processing data may enhance the receiving performance of the receiving system by performing additional coding and multiplexing processes on the traffic information data and transmitting the processed data. Thus, robustness is provided to the traffic information data, thereby enabling the data to respond strongly against the channel environment which is always under constant and vast change.
Abstract:
A digital broadcast transmitting/receiving system and a method for processing data are disclosed. The method for processing data may enhance the receiving performance of the receiving system by performing additional coding and multiplexing processes on the traffic information data and transmitting the processed data. Thus, robustness is provided to the traffic information data, thereby enabling the data to respond strongly against the channel environment which is always under constant and vast change.
Abstract:
Conventional rechargeable battery packs for portable electronic products possess charging terminals for connecting the battery packs to charging devices. When a portable electronic product is in use, there is a potential for short circuiting the battery pack by connecting one or more objects to the exposed charging terminals. This invention provides a battery pack for a portable electronic product with a short circuit prevention function where the charging terminal is exposed only when plugged into a charging device. By protecting the charging terminals, the invention prevents a short circuit from occurring during normal operation of the portable electronic product. The battery pack with a short circuit prevention function comprises a spring-loaded cover that is adapted to travel over the main body of the battery pack to alternately cover and expose the charging terminal.
Abstract:
An apparatus and method for testing mechanical endurance of a surface of an optical disc is disclosed, which includes a rotating plate on which the optical disc is fixed to generate scratch thereon, and rotating the fixed optical disc; and a plurality of abrasion wheels disposed in perpendicular to the rotating plate, and being in contact with the surface of the optical disc, to generate the scratch on the surface of the optical disc, wherein, the scratches generate when the optical disc rotates a predetermined turn, e.g. below ten turns for applying a predetermined load generated from the abrasion wheel on the optical disc.