The amount of reflected light fed back in the coupling of semiconductor lasers and tapered hemispherical-end (TH) fiber is estimated. Reflection from incident hemisphere is estimated to be below −50 dB, from the loss in the coupling between the laser and its virtual image. For multimode TH fiber reflection of backward-propagating light from connections can be reduced to below −50 dB by an ∼10-μm lateral displacement parallel to the junction plane; there is a small penalty in forward-coupling efficiency. The reduction of reflection is confirmed by measuring relative intensity noise of coupled laser light.
© 1983 Optical Society of America
Original Manuscript: January 15, 1983
Published: September 1, 1983
Hideo Kuwahara, Yoshihito Onoda, Masami Goto, and Takakiyo Nakagami, "Reflected light in the coupling of semiconductor lasers with tapered hemispherical end fibers," Appl. Opt. 22, 2732-2738 (1983)