Novel traveling wave-HPT technology with integrated polyimide optical waveguides

In realizing efficient heterojunction phototransistors (HPTs), classic design conflicts arise between the simultaneous optimization of high-frequency performance and optical coupling efficiency. In this paper, we propose to resolve these issues by utilizing a novel traveling wave AlInAs-InGaAs HPT (TW-HPT) configuration in which optical power transfer occurs along the sides of the device from a polyimide channel waveguide. Unlike p-i-n or MSM traveling wave implementations, this structure has gain at the IF frequencies.