Although no consensus yet exists as to the exact description of the process for preparing optical fibers for efficient frequency doubling, it is now generally believed that a periodical grating is written in the fiber with the simultaneous presence of fundamental and second-harmonic optical fields. The preparation process is practically permanent at room temperature, but it has been reported that frequency doubling can cease to occur in fibers under intense exposure to green light. Erasure experiments are important because they are most likely deal with the same physical mechanisms involved in the preparation process. Here we report a dramatic decrease in second-harmonic-generalion (SHG) efficiency by subjecting frequency-doubling fibers to either UV light or a heat treatment.

© 1991 Optical Society of America

PDF Article