Abstract: A wide passband optical interleaver includes a first optical splitter, having a first output terminal and a second output terminal. A first optical route is coupled to the first output terminal. A second optical route is coupled to the second output terminal. A delay is coupled on the second optical route. A second optical splitter having two input terminals is receiving the first optical route and the second optical route. A plurality of optical filter respectively having transmission coefficients ?i is coupled to the first optical route and the second optical route. The transmission coefficients ?i are determined by satisfying a desired quantity of effective group delay ratio T, defined as T = ? i ? S i ? 1 - ? i 1 + ? i , where ? ? S i ? ? is + 1 ? ? or - 1. where Si is +1 or ?1.

Abstract: A wide passband optical interleaver includes a first optical splitter, having a first output terminal and a second output terminal. A first optical route is coupled to the first output terminal. A second optical route is coupled to the second output terminal. A delay is coupled on the second optical route. A second optical splitter having two input terminals is receiving the first optical route and the second optical route. A plurality of optical filter respectively having transmission coefficients ?i is coupled to the first optical route and the second optical route. The transmission coefficients ?i are determined by satisfying a desired quantity of effective group delay ratio T, defined as T = ? i ? S i ? 1 - ? i 1 + ? i , where ? ? S i ? ? is + 1 ? ? or - 1. where Si is +1 or ?1.

Abstract: An optical coupler is provided, which includes at least one first-type delay part having a delay quantity; at least one second-type delay part having a basic delay quantity and an adjustable delay quantity; and a plurality of optical splitting units. The plurality of optical splitting units is connected to the first-type delay part and the second-type delay part between an input end and an output end, for example, connected in a cascade manner, so as to obtain a stable effective coupling ratio. Alternatively, any desired stable effective coupling ratio may also be obtained by a set of the adjustable delay quantity.