Abstract: An optical add/drop multiplexer capable of extracting signals from within a specified waveband in a group of signals containing various wavelengths, and then adding back a new set of signals also within the specified waveband. The multiplexer includes an optical filter plate, a plane reflector and three graded-index lenses. Using a single optical filtering plate and a plane reflector to carry out multiple reflections, intra-band isolation of light signals is improved and cost of production is reduced.

Abstract: A method of positioning reflecting mirrors inside a multi-level optical switch. The multi-level optical switch has a plurality of input terminals and a plurality of output terminals. A first fixed single-sided reflecting mirror and a second fixed single-sided reflecting mirror are installed such that the reflecting surfaces of the first and the second fixed single-sided reflecting mirrors face each other and are parallel to each other. The input terminals are divided into an odd group and an even group. Cross-points of optical paths are computed by feeding the input light paths from the odd group and the even group using a network exchange algorithm. Double-sided reflecting mirrors are positioned at the corresponding optical path cross-points in the double-sided reflecting mirror layout region of the multi-level optical switch.

Abstract: A multi-mirror reflection optical switch structure having two fixed reflecting mirrors and a plurality of parallel positioned double-sided reflecting mirrors, each capable of being raised or lowered. The plurality of double-sided reflecting mirrors are positioned along two to three 45° parallel axes that run from the upper lefthand corner to the lower righthand corner of the optical switch. Each double-sided reflecting mirror can be raised or lowered in order to perform the rearrangeable non-blocking one-to-one function of the 4-by-4 optical switch.

Abstract: The invention provides a structure of tunable optical filter grating. The structure includes a bimetallic strip and a compression spring to set up suitable strain for adjusting the position of the central wavelength. The bimetallic strip can also be specially designed to compensate for any drift in central wavelength due to temperature change so that temperature monitoring and feedback control designs is obsolete. Therefore, the operating wavelength of the optical grating is adjustable yet insensitive to temperature changes.

Abstract: A method of positioning reflecting mirrors inside a multi-level optical switch. The multi-level optical switch has a plurality of input terminals and a plurality of output terminals. A first fixed single-sided reflecting mirror and a second fixed single-sided reflecting mirror are installed such that the reflecting surfaces of the first and the second fixed single-sided reflecting mirrors face each other and are parallel to each other. The input terminals are divided into an odd group and an even group. Cross-points of optical paths are computed by feeding the input light paths from the odd group and the even group using a network exchange algorithm. Double-sided reflecting mirrors are positioned at the corresponding optical path cross-points in the double-sided reflecting mirror layout region of the multi-level optical switch.