Abstract

Single crystal fibres are grown by the Laser Heated Miniature Pedestal Growth technique [1] in lengths of up to ~ 50mm and with diameters in the range 50-500 μm. By this method, doped fibres, for example Cr³⁺ and Ti³+ in sapphire (alumina) for use in solid-state lasers or fibres of various nonlinear crystals may be produced. For laser action to be possible or for a fibre to be used in an optoelectronic device, there are several requirements to be met:-

(i) the fibre diameter and cross-section must be uniform,

(ii) the direction of the optic axis in an anisotropic crystal should be known,

(iii) the fibre ends should be flat and preferably normal to the fibre axis,

(iv) the fibre surface should be smooth so as to minimise scattering losses, and

(v) for a fibre to be incorporated into a laser cavity a polarised Gaussian beam entering the fibre at one end must emerge from the other as a Gaussian beam of a known state of polarisation.

© 1992 Optical Society of America