Low loss optical cascade devices

Abstract

A combination comprising a cascade of several optical devices with a low overall insertion loss, is disclosed. This arrangement can be used in many applications in the new technology area of dense wavelength division multiplexing. Specifically, this cascade arrangement can be used to fabricate compact, multichannel filter devices, dispersion compensators and other useful devices. Various embodiments are disclosed. In one embodiment, a 45-degree Faraday rotator is combined with another optical element. In another embodiment, a cascade of three optical devices is employed. Central to this is cascade is a cubic polarizing beam splitter (PBS) with four optical surfaces. In yet another embodiment, a cascade of five optical devices is described. Central to this cascade is an elongated polarizing beam splitter with six areas for optical coupling. This elongated PBS functions as a superposition of two cubic PBS. Various embodiments of the elongated PBS are also described. Another embodiment comprises a combination of a 45-degree Faraday rotator and a Gires-Tournois (GT) mirror.

Dependencies are inferred from the claim text.