We have found that borosilicate glasses that produce second-harmonic generation after simultaneous irradiation by fields at ω and 2ω exhibit postexposure selective etching. We use the charge specificity of the selective etching process to spatially map the photoexcited electron distributions responsible for second-harmonic generation. The results show that nearly symmetric nondipolar charge distributions exist for some regimes of encoding and that, at higher intensities, a nearly dipolar distribution is produced.
© 1996 Optical Society of America
Jae H. Kyung and N. M. Lawandy, "Direct measurement of photoinduced charge distribution responsible for second-harmonic generation in glasses," Opt. Lett. 21, 186-188 (1996)