A process of contactless monitoring the tension in an optical fiber and a tension meter which enables contactliess measurement of the tension in a bare and in a coated optical fiber. By measuring the retardation induced by the birefringence of an optical fiber by means of a polarized light beam incident to the fiber at an angle between about 10.degree. and 25.degree. to the detection optical axis, it is possible to accurately measure tensions over a wide range, i.e., from less than about 10 g to about 450 g. The method enables monitoring the tension during the ramp-up of the drawing process and is particularly advantageous for the control of the drawing tension in manufacturing of NZD, multimode or special fibers. Accurate monitoring of the tension both on a bare and on a coated fiber can also be achieved.