Intra-cavity loss-modulated diode laser

Claim 1

In an amplitude modulated diode laser comprising a double heterostructure having a substrate, an active layer and a cap layer, an improved heterostructure comprising: (a) an amplifier section comprising a doped portion of the active layer and a diode junction between the active layer and the substrate; (b) bias means for exciting the amplifier section; (c) a loss modulating section comprising a shallow ion-implanted portion of the cap layer and a second diode junction formed in the cap layer electrically isolated and physically remote from the active layer but capable of influencing the active layer when the second junction is reverse biased; (d) means for modulating the losses in the modulator section, the modulating means comprising (i) means for applying a reverse bias voltage to the second junction; and (ii) means for superimposing a modulating electric waveform upon the reverse bias voltage; and (e) a passive waveguide section located in the active layer between the amplifying and modulating sections and having low dopant concentration and sufficient length to electrically isolate the amplifying and modulating sections from each other, the heterostructure having cleaved ends with mirror facets defining a laser resonating cavity therebetween.