A surface mount type single-mode laser module using passive alignment

Abstract
A new single-mode laser module has been developed using the idea of surface mounting. A passive alignment technique and a simple connector interface simplify assembling in manufacture and mounting on the electrical circuit board. High productivity and compact size of 7.6 mm by 12 mm by 3 mm is achieved. A laser diode (LD) is passively positioned by detecting the position of a pair of marks on the LD and on the Si substrate. A single-mode fiber fabricated with a micro spherical lens on the fiber facet is positioned by mechanical aligning on a Si V groove. A LD single-mode fiber coupling loss of 5 dB and standard deviation 1.5 dB is achieved. The simple connector structure enables us to handle this module in the same way as other surface mount type electrical components. The module assembly process is simplified by successively mounting subassembly parts.