WAVELENGTH DIVISION MULTIPLEXING DEVICE WITH PASSIVE ALIGNMENT SUBSTRATE

A wavelength division multiplexing device includes an alignment substrate configured to provide alignment between optical components of the device. The device includes a plurality of collimating lenses, and the alignment substrate includes a plurality of aligners. Each of the aligners is configured to place a respective one of collimating lenses in a predetermined position and a predetermined orientation with respect to the other collimating lenses. The alignment substrate thereby provides passive alignment of the collimating lenses with a designed optical path. The substrate may also include visual alignment markings that provide an indication of the placement of multi-layer thin film filters so that the filters define an actual optical path in alignment with the designed optical path, and integrated optical waveguides that provide an optical beam to each of the collimating lenses.