Macrobend splice loss tester for fiber optic splices with silicon gel cushion on optical coupling blocks

Evanescent macrobend optic splice tester for testing the quality of a splice which joins first and second optical fibers which have a predetermined refractive index, comprising:

• first and second macrobend light launch units for injecting light at a predetermined wavelength into said first and second fibers to travel in respective first and second directions towards said splice, each said macrobend light launch unit including an optical coupling block formed of a transparent material with a refractive index substantially the same as said fibers and having a launch portion with a substantially cylindrical surface, an anvil with a generally cylindrical surface biasing the respective fiber into an arc against the respective optical coupling block launch portion, and light emitting means in optical contact with said optical coupling block for injecting light at said predetermined wavelength in a direction to intersect the respective fiber in its arc thereon;
• a macrobend light detection unit interposed between said first and second light launch units for detecting thereat the intensity of light from said first and second light launch units;
• including a detecting block formed of a transparent material with a refractive index substantially that of the optical fibers, and with a detecting portion having a cylindrical surface;
• an anvil member having a generally cylindrical surface which biases one of said first and second fibers into an arc against said detecting block cylindrical surface, and first and second light detecting elements in optical contact with said detecting block and having optical axes respectively oriented to intersect said arc to detect the level of light traveling through the fiber in said first and second directions and which emanates from the fiber biased therein;
• and
• control circuit means for controlling the light injecting means and receiving detected light levels from said first and second light detecting elements, and for computing splice loss occurring at the splice, based on said detected light levels,
• wherein said light launch units each contain a cushion layer of a clear silicon gel on said launch portion of said optical coupling block, and
• said detection unit includes a cushion layer of a clear silicon gel on said detecting portion of said detecting block.