PRACTICAL METHOD OF WAVE-GUIDE-TO-FIBER CONNECTION - DIRECT PREPARATION OF WAVE-GUIDE ENDFACE BY CUTTING MACHINE AND REINFORCEMENT USING RUBY BEADS

We propose and demonstrate new practical methods of waveguide end fabrication and fiber attachment for Ti:LiNbO3 waveguides. We fabricated waveguide endfaces with a cutting machine, which simplifies the manufacture of waveguide devices and provides a low excess loss of 0.3 dB or less. Our proposed fiber attachment method features fibers that protrude slightly from the reinforcement. It provides easy alignment, low excess loss (<0.1 dB), high strength (>600 gf), and high thermal stability (-10 to 60°C). We also developed an easy way to reduce the backreflection from the joint without using anti-reflection coating. Instead, a tapered hemispherical end fiber and an angled waveguide endface are used. Backreflection is easily reduced to less than —30 dB. © 1990 Optical Society of America.