A machining technique has been developed that enables a narrow, smooth damage-free walled trench to be cut into an optical fiber engraved in a silica substrate by using a fine silica powder effect. This technique allows a very low insertion loss (0.21 dB) in-line microfilter to be made by inserting a thin filter plate into a trench cut into an optical fiber already fixed to a substrate.
© 1992 Optical Society of America
Shinsuke Matsui, Tadao Saito, and Juichi Noda, "Low-loss in-line microfilter fabricated by precision trench machining," Appl. Opt. 31, 1252-1256 (1992)