Automated optical passive alignment technique for PLC modules

We have developed an automated optical passive alignment technique for planar lightwave circuit (PLC) modules. Our technique is based on aligning a laser diode (LD) on a PLC module, and can be used to create an optical network unit. The PLC module we propose consists of a LD and a photodiode, which are mounted on the surface of the PLC platform without a lens. Because these elements send light directly to the waveguide on the PLC platform and receive light from the waveguide, a precise alignment technique is required. We therefore developed the mirror image alignment method in order to automatically align the LD on the PLC with extreme accuracy. The method is effective regardless of the position of the LD and the thickness of the solder. The mirror image method uses the markers on the PLC and their images, which are reflected on the front wall of the LD. The achieved accuracy for positioning was within 1 micron in the lateral direction and within 0.5 degrees in the rotational direction. These systems are now being used at a Fujitsu factory.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.