Abstract: A light-emitting device of high light extraction efficiency comprises a first substrate, a light-emitting chip positioned on the first substrate and configured to emit light beams, a fluorescent material positioned on the light-emitting chip, a photonic crystal positioned on the fluorescent material and a reflector positioned on the photonic crystal and configured to reflect the light beam to the fluorescent material. The first substrate is preferably a metallic cup, and the light-emitting chip is positioned at the bottom of the metallic cup. The photonic crystal includes a second substrate and a plurality of protrusions positioned on the second substrate. Each of the protrusions includes a bottom end positioned on the second substrate and a tip portion smaller than the bottom end. The plurality of protrusions can be triangular pillars, semicircular pillars, sinusoid pillars, pyramids, or cones.

Abstract: A polarized light emitting device including a first reflector, an LED chip, a fluorescent layer, a second reflector and a polarizer with courragation structure is provided. In the polarized light emitting device, the LED chip emits a first light (e.g. ultraviolet light) confined within a resonant chamber configured by the first reflector and the second reflector, therefore the fluorescent layer can be adequately illuminated by the first light, thus emitting more second light (visible light) and improving the electro-optical transforming efficiency. The second reflector is adapted for reflecting the first light, and allows most of the second light to pass through. The polarizer with courragation structure disposed outside the resonant chamber is adapted for efficiently polarizing the second light.

Abstract: A light emitting diode with a quasi-omnidirectional reflector comprises a luminescent gel which is coated surrounding a UV light LED chip and a quasi-omnidirectional reflector which is disposed above the luminescent gel. The quasi-omnidirectional reflector is a wild angle cut-off filter which is made by a cooperation of a method for an optical film coating and a property of a total reflection. According to the property of the optical film coating, a light with an incident angle smaller than a critical angle can be reflected, such that a light form the LED chip is confined in the luminescent gel, which makes the luminescent material is excited as much as possible for improving the conversion efficiency of the light. When this LED chip co-works with different colors of the luminescent gels, different colors of lights are excited and produced.

Abstract: A color separation beam splitter for projectors is provided, which comprises a plurality of prisms connected with each other and three optical interference filters having different wavelength ranges respectively formed on side surfaces of the plurality of prisms. The three optical interference filters include a yellow color reflective dichroic mirror, a red color reflective dichroic mirror, and a blue color reflective dichroic mirror to filter out the yellow light and provide three primary color lights with high color purity. Moreover, by reflecting a light beam twice, the number of layers of dichroic mirror can be reduced. The color purity of the light is increased after reflected twice by the dichroic mirrors. Moreover, configuration of a liquid crystal projector by use of this prism assembly as color separation unit is also disclosed.

Abstract: A color separation beam splitter for projectors is provided, which comprises a plurality of prisms connected with each other and three optical interference filters having different wavelength ranges respectively formed on side surfaces of the plurality of prisms. The three optical interference filters include a yellow color reflective dichroic mirror, a red color reflective dichroic mirror, and a blue color reflective dichroic mirror to filter out the yellow light and provide three primary color lights with high color purity. Moreover, by reflecting a light beam twice, the number of layers of dichroic mirror can be reduced. The color purity of the light is increased after reflected twice by the dichroic mirrors. Moreover, configuration of a liquid crystal projector by use of this prism assembly as color separation unit is also disclosed.

Abstract: A composite optical film with a low refractive index mainly comprises calcium fluoride (CaF.sub.2), and silicon dioxide (SiO.sub.2) mixed with a specific composition ratio. The composite optical film is formed on a quartz substrate. The composite film is formed by using a coater, which accommodates two individual e-gun sources inside a cylindrical chamber. Oxygen is bled into the chamber. A heating process and plasma formation are performed to assist the process of forming the composite film. Additionally, a laser reflection lenses comprises an optical film with high refractive index and an optical film with low refractive index, which are alternately laminated onto a quartz glass substrate. The optical film with low refractive index uses a composite optical film mainly comprising calcium fluoride (CaF.sub.2) and silicon dioxide (SiO.sub.2) mixed with a fixed composition ratio.

Abstract: A multilayer thin-film broad-band polarizing beam-splitter which can split an unpolarized beam into two orthogonal linearly polarized beams with high extinction ratios is provided. The fabrication method comprises: (1) selecting a right-angle prism, having an isosceles triangular cutoff plane; (2) depositing broad-band polarized multilayer thin-film on an internal slope of the right-angle prism; (3) cementing and UV-curing a coated right-angle prism with an uncoated right-angle prism to form a cube-shaped polarizing beam-splitter; (4) properly determining the orientation of the polarization plane of the cube-shaped polarizing beam-splitter; (5) identifying the multi-stage assembly designs that are responsible for beam being incident and emerging; (6) adding anti-reflecting coatings to the relevant faces of the cube-shaped polarizing beam-splitters; and (7) cementing and UV-curing these cube-shaped polarizing beam-splitters.

Abstract: A thin-film color-selective beam splitter and the method of fabricating the same are disclosed. The method includes the steps of: (i) forming a main prism by a pre-selected material, and deciding a first base angle and a second base angle according to the substance and coating characteristics of the pre-selected material; (ii) coating a first multilayer film and a second multilayer film on two slopes of the main prism, in which tilt angles for coating the first multilayer film and the second multilayer film and tilt angles of light entering and emerging the main prism are different, so that spectra of the first multilayer film and the second multilayer film are different, and the first multilayer film can be a red reflective film and the second multilayer film can be a blue reflective film; and (iii) using the pre-selected material to form interface prisms, and adhering the interface prisms to the main prism, so that light can perpendicularly enter and emerge from surfaces of the prism.