The application of phase conjugation to crystal fibre optics

The characteristic optical transmission properties of crystal fibres grown by the laser-heated miniature growth technique are summarized. They convert an incident Gaussian beam to one possessing complex spatial intensity and polarization modulation by total internal reflection, birefringence and dif fraction. Phase conjugation is demonstrated as a method of restoring the tr ansmitted beam's intensity profile and polarization to that originally inci dent, enabling such fibres to be used as miniature laser media in phase con jugate cavities.