When a microscopic sphere is illuminated by a laser beam, interference fringes inside the sphere lead through the Kerr effect to a holographic grating. This grating is capable of phase conjugation, which is particularly strong when optical resonance takes place. According to numerical simulation, based on the Green function method, phase-conjugation reflectivity R=0.5 can be achieved in a single silica sphere of ~9-μm diameter with realistic laser power. Such spheres can be aligned together to become a phase-conjugation mirror of large area and high reflectivity.
© 2004 Optical Society of America
Xue-Heng Zheng, "Self-pumped phase conjugation in microspheres," J. Opt. Soc. Am. A 21, 2447-2454 (2004)