Abstract

We describe the performance of optical couplers that are used to transmit laser diode (LD) high optical power. Butt-coupled high-power Spectra Diode Laboratories (SDL) and McDonnell Douglas Astronautics Co./Opto Electronics Center (MDAC/ OEC) LD light sources are used to measure the transmission T of (1) GRIN lenses with 0.23, 0.25, 0.29, 0.5A, and 0.5B pitch (transmission, 90–97%), (2) filter optics (FO) with 600- and 1000-μm core diam butt-coupled each to a 0.5A- and 0.5B- pitch GRIN lens, (3) FO with 100-, 200-, 600-, and 1000-μm step-index fused-quartz core and hard-plastic cladding (transmission, 50–90.4% for SDL sources and 50–60% for MDAC/OEC sources); 200-μm diam step-index glass-on-glass (transmission 86%), and a 100-μm step-index glass-on-glass (transmission 68%), and (4) a BaK1 glass conventional lens (transmission 92 %). All FO are 1 m long except for the stub which is 0.95 cm long. The beam profiles out of the FO show that the intensity distributions vary from FO to FO. As the FO length decreases from 49 to 0.32 cm, the divergence Is found to increase from 11 to 23°. The divergence of a 1-m long 200-μm FO with a 15.2- by 21.6-cm loop positioned at mid-distance is 2.6° smaller than for the FO straight.

© 1988 Optical Society of America