Abstract: An optical filter includes a transparent substrate, a first film stack and a second film stack. The first and second film stacks each includes a number of high refractive index layers and a number of low refractive index layers alternately stacked one on another. The first film stack is defined as (HL)7(0.76H0.76L)6, and the second film stack is defined as 0.5(HL)(1.3H1.3L)9(HL)8, wherein, H represents a high refractive index layer having a base optical thickness equal to one fourth of a first reference wavelength associated with the optical filter, L represents a low refractive index layer having a base optical thickness equal to one fourth of a first reference wavelength associated with the optical filter, the expression enclosed in each parenthesis represents a filter cavity, and the superscript represents the number of repetition of the expression enclosed in that parenthesis.

Abstract: An optical filter for screening out infrared and ultraviolet light includes a transparent substrate and a film stack formed on the substrate. The film stack includes a number of high refractive index layers and a number of low refractive index layers alternately stacked one on another. The film stack is represented as follows: (3.5H3.5L)7(2.5H2.5L)7(HL)6(0.76H0.76L)6, wherein, H represents a high refractive index layer having a base optical thickness equal to one fourth of a reference wavelength associated with the optical filter, L represents a low refractive index layer having a base optical thickness equal to one fourth of a reference wavelength associated with the optical filter, expressions enclosed in each parenthesis represent filter cavities, and superscripts represents the number of repetitions of the expression enclosed in that parenthesis.

Abstract: An optical element includes a substrate having a first surface and an opposite second surface; a first film stack formed on the first surface, having a plurality of first film layers with predetermined thickness or layer numbers; and a second film stack formed on the second surface, having a plurality of second film layers with same thickness or layer numbers to the first film layers. A method for manufacturing the optical element is also provided.

Abstract: An induction charger assembly (3) is provided for an electronic device (4). The induction charger assembly includes an induction coil (311), a charger connector (35), and a magnetic element (313). The induction coil is configured to be hollow column in shape, and the induction coil has a first end and a second end. The charger connector electrically connects with the first and second ends of the induction coil. The charger connector is configured for electrically connecting with the electronic device to be charged. The magnetic element is received in the induction coil. The permanent magnet is movable in the induction coil for generating an induction current through the induction coil.