Passively Aligned Transmit Optical Subassembly Module Based on a WDM Incorporating VCSELs

A short-reach transmit optical subassembly module enabled by a passive alignment has been proposed and manufactured which takes advantage of a filter free coarse wavelength-division multiplexer (WDM). A four-channel data transmission was accomplished by employing only two plastic optical fibers and four vertical-cavity surface-emitting lasers (VCSELs). A multiaxis beam combination was introduced to overcome the use of WDM filters. The proposed module was constructed via a passive alignment; the overall alignment tolerance was examined by assessing the optical coupling efficiency in terms of the VCSEL displacement. The achieved tolerance was ~20 and ~150 μ m in the horizontal and vertical direction respectively, while the demonstrated peak coupling was ~41%. Finally, a high-speed 2.5-Gb/s signal was successfully delivered via the demonstrated module.