We report on photo-detectors consisting of an optical waveguide that incorporates
a resonant tunneling diode (RTD). Operating at wavelengths around 1.55 μm in the optical
communications C band we achieve maximum sensitivities of around 0.29 A/W which is
dependent on the bias voltage. This is due to the nature of RTD nonlinear current-voltage
characteristic that has a negative differential resistance (NDR) region. The resonant
tunneling diode photo-detector (RTD-PD) can be operated in either non-oscillating or
oscillating regimes depending on the bias voltage quiescent point. The oscillating regime is
apparent when the RTD-PD is biased in the NDR region giving rise to electrical gain and
microwave self-sustained oscillations Taking advantage of the RTD’s NDR distinctive
characteristics, we demonstrate efficient detection of gigahertz (GHz) modulated optical
carriers and optical control of a RTD GHz oscillator. RTD-PD based devices can have
applications in generation and optical control of GHz low-phase noise oscillators, clock
recovery systems, and fiber optic enabled radio frequency communication systems.info:eu-repo/semantics/publishedVersio
