Abstract

Tunable semiconductor lasers¹ that can be tuned over a broad spectral range are of great interest for a number of applications. Multisection DBR or DFB laser diodes having tuning range of several nanometers have been reported. Another attractive solution is to use cavity extended lasers in which tunability is performed with an intracavity spectral filter such as a rotating grating,² an acoustooptic cell,³ or an electrooptic modulator.⁴ We describe here another type of extended cavity laser diode in which the resonator is an optical fibre loop and the active medium is a semiconductor amplifier.⁵ The wavelength tuning system is an intracavity electrooptic biréfringent element.

© 1994 IEEE