Abstract

It has recently been shown that a phase-matched χ⁽²⁾ grating can be written in an optical fiber by irradiating it simultaneously with light at the fundamental and harmonic wavelengths for a period of time.¹ We have found that this χ⁽²⁾ grating can be erased optically by irradiating the fiber with light of suitable wavelength and intensity. Gratings written with light at 1.06 μm and 532 nm in a single-mode germanium-doped fiber (with no phosphorus) were erased when only the mode-locked Q-switched light at 532 nm was launched into the fiber. Irradiation with intense light from a cw argon laser also accomplished the erasure. The decay of the conversion efficiency as a function of irradiation time was not exponential but could be fitted to a model where the amplitude of the grating A decays proportionally to A². The decay constant was found to be proportional to Iⁿ, where n = 4.4 + 1.2 and I is the erasing intensity.

© 1988 Optical Society of America