Brillouin-Based Carrier Amplification for Kramers-Kronig Receivers

Self-coherent receivers have gained increased popularity in recent years due to the evolving demands and trends in optical communication, especially in short-reach, high-speed applications such as data center interconnects (DCIs). These receivers garnered immense attention with the advent of the Kramers-Kronig (KK) receiver architecture. The KK algorithm reconstructs the complex optical field (amplitude and phase) from the intensity of a minimum-phase signal [1] while using a simple PIN detector without the need for a conventional coherent receiver. There are two fundamental requirements of KK receivers: the transmitted signal must be single sideband (SSB) and should have a high carrier-to-signal power ratio (CSPR) for minimum phase condition and upsampling of the photodetected signal at the receiving end, thereby ensuring that KK receivers could reconstruct the transmitted signal accurately and efficiently in high-speed optical communication systems [1], [2].