Devices for backscattered and reflected signals processing based on integrated photonics

In this article we present the brief review of different scenarios of using the photonic integrated circuits (PIC) in the swept-source optical coherence tomography (SS-OCT) with different degree of integration and propose implementation of PICs on the Si/Ge manufacturing technology with integrated analogous balanced photodetectors. The first PIC implementation contains two arms for processing backscattered light and light reflected in “off-axis” mode on the same chip. We present results of simulation of such PIC that demonstrate its functionality. The second PIC implementation provides functionality for the optical processing of the backscattered signals and includes integrated narrow-band filter based on the adjustable unbalanced Mach-Zehnder interferometer for reseting the digital signal processor in the beginning of the every period of the frequency sweep. Implementing the SS-OCT functionality on the PIC will make possible to reduce the cost of the final device, as well as significantly reduce its geometric size, which is an important factor that provides portable use.