Wideband four-channel optical transmitter package using vertical cavity surface emitting laser arrays

We report on the fabrication of a prototype multichannel optical transmitter based on vertical-cavity surface- emitting lasers (VCSELs). The package consists of an array of four VCSELs, mounted directly on a RF circuit board, and UV-curable polymer microlenses and waveguides which couple the laser output to a multimode fiber ribbon. Light from the lasers is captured by refractive polymer microlenses positioned on a glass substrate above the VCSEL array. The lenses focuses the light signals onto angled reflective end facets in the polymer waveguides. These waveguides are situated on a separate glass substrate which is bonded to the lens substrate. The light is then coupled form the waveguides to a multimode fiber ribbon; the average measured coupling efficiency was 47.5 percent +/- 3 percent. Experimental measurements reveal an analog bandwidth of 2.65 GHz per channel with better than 30 dB isolation between adjacent channels for frequencies up to 2 GHz without active heatsinking. In addition, it has been experimentally verified that this isolation is limited by the parasitics inherent in the VCSEL array rather than the parasitics of the device driver circuitry.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.