Patent ID: 6381049
Filing Date: 2002-04-30
Classification: G02B,H04B

Abstract:
A multi-port wavelength division multiplexing (WDM) element, comprising:ports configured to couple the WDM element to a respective set of external optical fibers capable of carrying light signals at a plurality of wavelengths; and a discrete filter element separate from but optically coupleable to the external optical fibers having first and second substantially planar parallel filter surfaces, a filter body defined between the first and second filter surfaces, and transmission and reflection bands configured to: couple first light signals input at a first port to a second port by reflection at the first filter surface, the first light signals having first wavelengths that are within the reflection band of the discrete filter element; couple second light signals input at the first port to a third port by transmission through the first surface, the filter body, and the second surface, the second light signals having second wavelengths that are within the transmission band to the filter element; couple third light signals input at the third port to a fourth port by reflection at the second filter surface, the third light signals having third-wavelengths that are within the reflection band of the filter element; and couple fourth light signals input at the third port to the first port by transmission through the second surface, the filter body, and the first surface, the fourth light signals having fourth wavelengths that are within the transmission band of the filter element.