Towards high-speed optical coherence tomography through downconversion master slave and bidirectional sweeping

This paper presents the challenges of signal processing in optical coherence tomography (OCT) imaging systems using asymmetric MHz bidirectional sweeping lasers. It proposes a downconversion master-slave method as an alternative to traditional OCT protocols. This method uses analogue electronics to produce a downconverted radio frequency signal from the product between a master and a slave interferometer. The product compensates for sweep-to-sweep variations in laser emissions in real-time, eliminating the need for calibration. En-face images are demonstrated using a bidirectional laser sweeping at a rate of 1.6 MHz and a slow acquisition card with a sampling rate of only 2.5 MS/s.