Design, fabrication, and evaluation of crystal-cored fibers for efficient second-harmonic generation based on Cerenkov-radiation-type phase matching.
A formulation for calculating the optical second-harmonic power based on the Cerenkov-radiation-type phase matching is derived for a crystal-cored fiber. The prerequisite condition for high efficiency is expressed by a simple relation by use of the refractive indices of a core crystal, a core radius, and a fundamental wavelength. An organic crystal-cored fiber is designed and practically fabricated by the guiding principle derived here. A blue second-harmonic wave of 1.4 mW is obtained from a 1-mm-long fiber by use of a 60-mW semiconductor laser, and the second-harmonic intensity agrees well with the prediction. Degradation of the organic core crystal caused by the generated blue wave is observed, and the lifetime of the device is evaluated.
Chikuma
Kiyofumi
K
Corporate Research and Development Laboratory, Pioneer Corporation, 6-1-1 Fujimi, Tsurugashima, Saitama 350-2288, Japan. vyc03054@nifty.com
Okamoto
Sota
S
Uenishi
Naota
N
Uemiya
Takafumi
T
Umegaki
Shinsuke
S