Integrated electro-optic intracavity frequency modulation of double-heterostructure injection laser

Abstract

Integration of a taper-coupled GaAs-AlxGa1-xAs laser with a linear electro-optic modulator permits efficient optical frequency modulation of the laser emission. The pulsed room-temperature threshold current density of the device was 8 kA/cm2. Frequency modulation depth in excess of 15 GHz (corresponding to a wavelength shift of 0.4 Å) was obtained with a reverse bias change of 20 V across the modulator. Conversion of frequency modulation into intensity modulation was demonstrated with a characteristic power P0 of 10 μW/MHz for 90% intensity modulation. It is shown that reduction of P0 by an order of magnitude is easily feasible.