The PL-BC-1550-6.9-0016-37.1 from LD-PD Inc is a Fixed Focus Large Beam Collimator that operates at a central wavelength of 1550 nm. It has an effective focal length of 37.1 mm and a lens coating wavelength of 1050 nm - 1700 nm. This collimator has a transmissivity above 95% and beam divergence angle of 0.016 degrees. It has a girdle flare of 6.9 mm and numerical aperture (lens) of 0.24. This collimator uses air-gap glued lens coated with antireflective film to minimize surface reflection. It uses input SMF-28e fiber and supports FC, PC, APC & SMA905 connectors. This collimator is available in a package that measures 44.25 mm x 24 mm and is ideal for collimation transmission & coupling reception applications.