Abstract
An external-cavity semiconductor laser employing a birefringent electro-optic modulator for wavelength tuning is described. Wide-band tuning over 70 Å in a single frequency to residual diode modes and narrow-band tuning over 0.42 Å to many longitudinal modes of the external cavity is demonstrated using different modulator configurations. Threshold current and quantum efficiency are nearly as good as that of the solitary laser diode.