Abstract: A structure and method are provided to improve stability of a multi-window dense wavelength division multiplexers and to provide polarization-independent multi-window dense wavelength division multiplexers. In one embodiment, the coupler region of a multi-window wavelength division multiplexer (MWDM) is hermetically sealed in a protective casing to prevent moisture from affecting the passband wavelength drifting in the coupler. In one embodiment, the coupler is elastically twisted at the fused fiber portion to reach polarization cancellation. In another embodiment, the coupling region of the coupler is exposed to UV-radiation for passband wavelength adjustment. In yet another embodiment, a passive thermal compensation technique is used to minimize the thermal effect on the passband wavelengths for dense WDM applications. In a further embodiment, the coupler is mounted on the substrate using soft adhesives in conjunction with rigid adhesives, to improve mechanical shock protection.

Abstract: A protective cover apparatus for an automobile (30) includes a cover (11) covering-passenger compartment (32) of the automobile (30), a semi-pliable metal hook (17) linked to a handhold (13) on the cover (11) by a cord(16) for securing the cover (11) to the front of the automobile (30), a storage pouch (18) for storing the the cover (11) and an adjustable belt (19) fixed to the storage pouch (18) for securing the pouch (18) and the cover (11) to the trunk (34) of the automobile (30). In a second arrangement, the front end of the cover (11) is secured to the windshield (35) by suction pads (55) under the handhold (13). The storage pouch (18) is replaced by a pair of tie-down straps (50) and a roll-up sheet (51). The tie-down straps (50) tie the folded cover (11) to the roll-up sheet (51) before the roll-up sheet (51) wraps up the cover (11) for storage. Both arrangements are similiar in operation but have different advantages in manufacturing.