Optical demultiplexing/multiplexing device having a wavelength dependent element

摘要

A device capable of demultiplexing or multiplexing optical signals includes a wavelength dependent element for separating an input beam into sub-beams of light in accordance with their wavelength. Precisely spaced optical fibers are disposed to receive at least some of the sub-beams of light; a focusing lens is disposed between the wavelength dependent element and the optical fibers for focusing the sub-beams at ends of the optical fibers. A rod-like GRIN lens for correcting for an offset in the focal length of the focusing lens is placed between the focusing lens and the optical fibers. The GRIN lens can be polished to change its length in order to correct for the offset in focal length of the focusing lens.