Small size and low-cost surface mountable LD and PD optical module : Special issue on optical transmission components

Recently, the application area of optical fiber communications has been expanding from trunk lines to subscriber loops and LANs (Local Area Networks). Realization of low-cost devices is one of the most important requisites to expand subscriber optical networks. This paper describes the technologies to realize drastic low-cost Laser Diode (LD) modules. Most of LD modules' costs are assembly costs because of the complicated assembly, so simple assembly procedure is required for both automatic assembly and lower cost. Passive alignment technique is the key method for low-cost optical coupling. Optical coupling can be automatically assembled by using the passive alignment technique. We have also developed a simple detachable connector for automatic assembly and low-cost mounting. The SMT (Surface Mountable) optical module has been designed for high productivity and compact size by using the optical passive alignment technique and a simple detachable connector structure. The SMT module can be assembled by a fully automatic assemble line. Besides, the SMT module can be mounted on Printed Wiring Board (PWB) by automatic surface mounting process to reduce mounting cost. In this paper, new techniques for low-cost module assembly and the features of SMT module are introduced.