Vs. Ilchenko et al., Pigtailing the high-Q microsphere cavity: a simple fiber coupler for optical whispering-gallery modes, OPTICS LETT, 24(11), 1999, pp. 723-725
We demonstrate a simple method for efficient coupling of standard single-mo
de optical fibers to a high-Q optical microsphere cavity. Phase-matched exc
itation of whispering-gallery modes is provided by an angle-polished fiber
tip in which the core-guided wave undergoes total internal reflection. In t
he experimental setup, which included a microsphere with both an input and
an output coupler, the total fiber-to-fiber transmission at resonance reach
ed 23% (total insertion loss, 6.3 dB), with loaded quality factor Q greater
than or equal to 3 x 10(7) and unloaded Q approximate to 1.2 x 10(8) at 15
50 nm. A simple pigtailing method for microspheres permits their wider use
in fiber optics and photonics devices. (C) 1999 Optical Society of America.