Photonic integrated circuits for microwave photonics applications

Abstract

Abstract —We propose and demonstrate photonic arbitrary waveform generation based on microwave photonic filtering. We show uniform and apodized waveforms, as well as tuning of the RF spectrum. We discuss how the photonic structure can be fully integrated in silicon photonics. Keywords—Microwave photonics, arbitrary waveform generation, silicon photonics I. I NTRODUCTION The development of photonic approaches for RF arbitrary waveform generation (RF-AWG) are of interest due to advantages of being tunable, reconfigurable, and compatible with fiber optic transmission [1]. Indeed, a number of photonic structures and techniques for RF-AWG have been demonstrated, including those based on nonlinear optical effects in fiber or semiconductor optical amplifiers, optical frequency comb generation, phase modulation-to-intensity modulation using discrimination filters, and microwave photonic filtering [2-6]. The field of microwave photonic filters (MPFs) is extremely rich and the design of MPFs with reconfiguration and/or tuning capabilities has been the subject of intense research. Many structures have been proposed and important results have been demonstrated [6]. MPFs employ typically discrete components resulting in bulky, benchtop implementations. To address issues related to compactness, stability, power consumption, and ultimately mass production for reduced cost, the development of integrated (single chip) MPFs will be significant. There have been several integrated MPFs and MPF systems reported in chalcogenide and silicon (including silicon nitride) [7-10]. Those based in silicon are especially attractive for their compatibility with CMOS processing. In this paper, we demonstrate RF-AWG based on microwave photonic filtering. We also discuss the integration of the various building blocks and the possibility for a fully photonic integrated circuit (PIC) equivalent. II. G