| A monolithically integrated balanced electroabsorption mixer receiver (B-EMR) was fabricated and experimentally demonstrated for the first time. It has the potential to eliminate the need for microwave mixers found in superheterodyne analog receivers. The B-EMR is composed of a 1 x 2 multimode interference (MMI) optical power splitter, a balanced electroabsorption modulator (B-EAM), and a balanced photodetector (B-PD). This novel device requires only one optical input, generates and detects the differential signals on-chip, and therefore, is not sensitive to environmental changes that cause amplitude or phase mismatch. All common mode noises (laser relative intensity noise, signal-amplified-spontaneous-emission (ASE) beat noise, ASE-ASE beat noise) and even-order distortions generated by the on-chip B-EAM are suppressed by the balanced architecture. Theoretical simulations predict that the B-EMR has the potential to improve spurious free dynamic range and noise figure by 25 dB and 30 dB, respectively, compared to conventional series cascaded downconverting fiber-optic links.;An integration platform based on an evanescently coupled waveguide structure is adopted to integrate the passive waveguides and active devices onto a single chip. The on-chip B-EAM and B-PD are built as waveguide p-i-n photodiodes and share a common bulk electroabsorption layer. They are evanescently coupled to an underlying large core passive waveguide. This design buries the optical mode beneath the semiconductor surface and allows the doping in the p-type layers to be maximized for low series resistance without adversely affecting the propagation loss. Optical mode transformers are also incorporated to provide adiabatic transitions between the dissimilar passive and active waveguides.;A baseline manufacturing process was developed and a prototype B-EMR was successfully fabricated. The integrated 1 x 2 MMI demonstrated 24 dB common mode rejection ratio at 1.55 mum wavelength. Microwave measurements verified on-chip tunable IF from 400 to 800 MHz. Linear downconversion from 10 GHz to 1 GHz was achieved up to the maximum available microwave local oscillator power. Further improvements are possible and this dissertation provides the system and component level design tools necessary to enhance the B-EMR's performance. |
