Abstract

Upconversion-pumped Pr.Yb-doped ZBLAN fibres have attracted increasing attention recently because of their ability to produce high-power laser output in the visible spectral range, namely at a wavelength of 635 nm [1]. Possible applications include display technology and optical communication as well as medicine. Many of these require modulated laser output. In principle, this can be achieved by introducing acousto-optical or electro-optical devices in the output beam. Unfortunately, the first method imposes a serious limitation on the maximum attainable modulation frequency, while the second requires linearly polarized light to be applicable without excess losses. Alternatively, direct modulation of a low-power diode laser seeding a fibre amplifier (Master Oscillator Power Amplifier configuration) should lead to high-frequency modulated high-power output. We report on a Pr.Yb:ZBLAN fibre amplifier seeded by a 635 nm diode laser.

© 1998 IEEE