Abstract: A method and device is disclosed for relaying a narrow diameter collimated optical beam carrying optical communication signal channels between a multilayer interference filters and another reflective surface avoiding signal loss by routing the optical beam to compensate for beam broadening caused by the multilayer interference filter. The method and device are particularly applicable to dispersion compensating filters, especially those wherein one filter is tunable, in that a controllable amount of dispersion is introduced to offset or compensate dispersion. Preferably one of the filters is a tunable periodic device in the form of a multi-cavity etalon structure. In a preferred embodiment of the filters can be designed to provide various controllable but different constant amounts of dispersion.

Abstract: A method and device is disclosed for relaying a narrow diameter collimated optical beam carrying optical communication signal channels between a multilayer interference filters and another reflective surface avoiding signal loss by routing the optical beam to compensate for beam broadening caused by the multilayer interference filter. The method and device are particularly applicable to dispersion compensating filters, especially those wherein one filter is tunable, in that a controllable amount of dispersion is introduced to offset or compensate dispersion. Preferably one of the filters is a tunable periodic device in the form of a multi-cavity etalon structure. In a preferred embodiment of the filters can be designed to provide various controllable but different constant amounts of dispersion.

Abstract: A method and system are provided for measuring a characteristic of a lens. By directing light to a lens, and receiving reflected light from a opposite end faces of the lens on an image plane, a determination from the focused spots on the image plane can be made as to a characteristic of the lens, such as its focal length.