Improved methods and systems for routing and aligning beams and optical elements in an optical device include a multiplexing device and/or a demultiplexing device, which includes an optical alignment element (OAE). The OAE can be configured to substantially compensate for the cumulative alignment errors in the beam path. The OAE allows the optical elements in a device, other than the OAE, to be placed and fixed in place without substantially compensating for optical alignment errors. The OAE is inserted into the beam path and adjusted. This greatly increases the ease in the manufacturing of optical devices, especially for devices with numerous optical elements, and lowers the cost of manufacturing. The multiplexing and/or demultiplexing device can reside within a standard small form factor, such as a GBIC. The devices fold the paths of the traversing beams with a geometry which allows a small package.