Abstract: A projection lens for projecting an image onto a projection plane includes: a lens substrate; and an antireflective film disposed on a surface of the lens substrate. The antireflective film includes, in order starting from an air side of the antireflective film, a first layer, second layer, third layer, fourth layer, fifth layer, sixth layer, seventh layer, and eighth layer. The first layer is formed of MgF2. Each of the second layer, the fourth layer, the sixth layer, and the eighth layer has a refractive index of 2.0 to 2.3. Each of the third layer, the fifth layer, and the seventh layer is formed of SiO2.

Abstract: A projection lens for projecting an image onto a projection plane includes: a lens substrate; and an antireflective film disposed on a surface of the lens substrate. The antireflective film includes, in order starting from an air side of the antireflective film, a first layer, second layer, third layer, fourth layer, fifth layer, sixth layer, seventh layer, and eighth layer. The first layer is formed of MgF2. Each of the second layer, the fourth layer, the sixth layer, and the eighth layer has a refractive index of 2.0 to 2.3. Each of the third layer, the fifth layer, and the seventh layer is formed of SiO2.

Abstract: An optical element includes: an optical element substrate; and an antireflective film on the optical element substrate. The antireflective film has a structure in which, in order from an air side of the anti-reflection film, a SiO2 low-refractive index film and one or more TiO2, Nb2O5, or Ta2O5 high-refractive index films are alternately stacked in eight or more layers.

Abstract: A projection lens included in a projector using laser beams as a light source is provided, the laser beams including as the light source, first blue laser light beams, second blue laser beams, first green laser beams, second green laser beams, first red laser beams, and second red laser beams, which are different in wavelength range. The projection lens has a relative maximum value of a transmittance on an optical axis between a wavelength not shorter than 645 nm and a wavelength not longer than 680 nm.

Abstract: A prism unit that combines light in the three primary colors of R, G, and B on the same optical axis includes: a G-reflecting dichroic coating that reflects G light and passes R and B light; and an RB dichroic coating that reflects one of R and B, and passes the other one of R and B, the prism unit satisfying the following conditional expression: ?rg??rb?0.67×?rg+0.33×?gb, where ?gb represents the wavelength at which the transmittance is 50% when the colors of G and B on the composite optical axis are combined, ?rg represents the wavelength at which the transmittance is 50% when the colors of R and G on the composite optical axis are combined, and ?rb represents the wavelength at which the transmittance is 50% when the colors of R and B on the composite optical axis are combined.

Abstract: A projection lens included in a projector using laser beams as a light source is provided, the laser beams including as the light source, first blue laser light beams, second blue laser beams, first green laser beams, second green laser beams, first red laser beams, and second red laser beams, which are different in wavelength range. The projection lens has a relative maximum value of a transmittance on an optical axis between a wavelength not shorter than 645 nm and a wavelength not longer than 680 nm.

Abstract: A prism unit that combines light in the three primary colors of R, G, and B on the same optical axis includes: a G-reflecting dichroic coating that reflects G light and passes R and B light; and an RB dichroic coating that reflects one of R and B, and passes the other one of R and B, the prism unit satisfying the following conditional expression: ?rg??rb?0.67×?rg+0.33×?gb, where ?gb represents the wavelength at which the transmittance is 50% when the colors of G and B on the composite optical axis are combined, ?rg represents the wavelength at which the transmittance is 50% when the colors of R and G on the composite optical axis are combined, and ?rb represents the wavelength at which the transmittance is 50% when the colors of R and B on the composite optical axis are combined.

Abstract: A mode control section controls an image generation section to operate in a normal mode or a polarized light component reduction mode on the basis of a mode signal from a mode signal generation section to cause the image generation section to form a normal image or a polarized light component reduced image. When the possibility of occurrence of stray light is high, the imaging device automatically switches to the polarized light component reduction mode and when the possibility of occurrence of the stray light is low, the imaging device automatically switches to the normal mode. The polarized light component reduced image is obtained by reducing or eliminating stray light having a polarized light component, and the normal image is formed without reducing the stray light. Thus, the imaging device is capable of automatically switching between the two modes.

Abstract: A monitor optical device has a first region and a second region. The first region transmits part of light beam emitted from a light source to introduce the transmitted light beam to a monitor device. The second region reflects the remainder of the light beam to introduce the reflected light beam to an optical disk. The first region is formed at least within the second region.

Abstract: In a reflecting mirror, an adhesive layer formed of a mixture of silicon dioxide and aluminum oxide is formed between a substrate and an aluminum reflective layer, and, on the aluminum reflective layer, a dielectric layer is formed that has, laid one after another on the aluminum reflective layer, a low-refraction layer containing silicon dioxide and a high-refraction layer formed of a compound of titanium oxide and lanthanum oxide.

Abstract: An optical element has a dichroic film held between transparent materials which transmits one of first light in a wavelength range of 390 to 425 nm and second light in a wavelength range of 630 to 820 nm and reflects the other light, and a first, a second, a third and a fourth surfaces. In the optical element, a first anti-reflection film for preventing reflection of the first light is formed on the first surface, a second anti-reflection film for preventing reflection of the second light is formed on the second surface, and a third anti-reflection film for preventing the reflection of the first and the second light is formed on the third surface from which the incident light of the first surface and the second surface is emitted. In the third anti-reflection film, reflectance of the second light is larger than that of the first light.

Abstract: On the surface of a plastic base, there are formed, from the base side, an adhesion layer, a reflective layer formed mainly of Ag, and a protective layer formed of a light-transmitting dielectric layer. The adhesion layer is formed of a layer of a mixture of aluminum oxide and lanthanum oxide, and is given a thickness in the range from 10 nm to 120 nm. To further enhance the adhesion between the base and the Ag layer, and to surely prevent entry of moisture or the like from the base into the Ag layer, the mix proportion of lanthanum oxide in the adhesion layer is preferably kept in the range from 60% to 80% by weight.

Abstract: A rising mirror is constructed by forming on a glass substrate a first region and a second region having different reflection properties. The first region is formed of, for example, an antireflection film, and the second regions is formed by superimposing a phase adjustment layer for adjusting the phase of reflected light and a dielectric multilayer film in this order. Forming the phase adjustment layer on the glass substrate in this manner permits, for example, phase adjustment such as eliminates phase shift in reflected light between the regions, and phase adjustment such as cancels out phase shift caused by the objective lens of the optical disc, thereby permitting suppressing disturbance in the wave front of reflected light as whole.

Abstract: A monitor optical device has a first region and a second region. The first region transmits part of light beam emitted from a light source to introduce the transmitted light beam to a monitor device. The second region reflects the remainder of the light beam to introduce the reflected light beam to an optical disk. The first region is formed at least within the second region.

Abstract: An optical element has a dichroic film held between transparent materials which transmits one of first light in a wavelength range of 390 to 425 nm and second light in a wavelength range of 630 to 820 nm and reflects the other light, and a first, a second, a third and a fourth surfaces. In the optical element, a first anti-reflection film for preventing reflection of the first light is formed on the first surface, a second anti-reflection film for preventing reflection of the second light is formed on the second surface, and a third anti-reflection film for preventing the reflection of the first and the second light is formed on the third surface from which the incident light of the first surface and the second surface is emitted. In the third anti-reflection film, reflectance of the second light is larger than that of the first light.

Abstract: In an optical element having an optical substrate and a laminate having high-refractive-index and low-refractive-index layers laid on top of one another, the low-refractive-index layers are formed of a mixture of Al2O3 and SiO2. Alternatively, in an optical element having an optical substrate and a laminate having high-refractive-index and low-refractive-index layers laid on top of one another, the low-refractive-index layers are formed of a mixture of SiO2 and a material having a refractive index approximately equal to the refractive index of SiO2 and having a property of mitigating compression stresses in SiO2, and the high-refractive-index layers are formed of a material based on titanium oxide.

Abstract: On a waveguide 34 formed on a substrate 33, a plurality of comblike shaped electrodes 37, 38 that generate surface acoustic waves 37a, 38a from different directions are provided. And a periodic refractive indices portion 40 is formed, where the refractive indices are periodically distributed in accordance with the wavelengths of the surface acoustic waves 37a, 38a generated by applying a voltage to the comblike shaped electrodes 37, 38. And by changing a frequency of the applying voltage for sequentially changing the wavelengths of the surface acoustic waves 37a, 38a, the exiting direction of the light exiting from the periodic refractive indices portion 40 is scanned. This makes it possible to provide an optical functional device and an optical scanning apparatus that perform light scanning less costly but at a high speed, and that can secure a wide scanning angle.

Abstract: Disclosed herein is an optical switch for changing over a running direction of a light passing through an optical waveguide between a first direction and a second direction by moving a switching member disposed on an optical path of an optical waveguide. The switching member has a plurality of switching positions for selectively guiding each of lights of at least two different wavelengths into the first direction or second direction.

Abstract: An optical waveguide is produced by forming on a substrate a waveguide layer and/or a clad layer containing, as their main ingredient, polyimide with a fluorine substitution rate of 30% or higher (thus as a fluorinated polyimide layer), with a primer layer laid in between that contains, as its main ingredient, polyimide with a fluorine substitution rate of 10% or lower (including 0%). This improves adherence of the fluorinated polyimide layer to the substrate and prevents the fluorinated polyimide layer from peeling off the substrate. For more effective prevention of such peeling-off and of warping of the substrate, the primer layer is preferably formed to have a thickness of 0.1 to 20 &mgr;m. The primer layer may contain a coupling agent.

Abstract: Disclosed herein is an optical switch for changing over a running direction of a light passing through an optical waveguide between a first direction and a second direction by moving a switching member disposed on an optical path of an optical waveguide. The switching member has a plurality of switching positions for selectively guiding each of lights of at least two different wavelengths into the first direction or second direction.