Spectral Division of the Optical Fiber Passband Using Narrowband Controllable Filter on the Baseof Semiconductor Waveguide Microresonator, Journal of Telecommunications and Information Technology, 2008, nr 4

We analyze the new principle of multichannel spectral division of optical fiber passband using controllable narrowband integrated optical filters composed of two-coupled ring microresonators made of different semiconductor materials. It is shown that appropriate selecting the semiconductor material and optimizing the design factors of selective optical element allows creating the simple and economical integrated optical filter with bandwidth 0.1 nm, frequency separation between adjacent optical carriers 0.2 nm and signal-to-noise ratio 50 dB. Utilizing such filters in optical fiber communication lines makes it possible to increase the number of transmitted in parallel optical carrier wavelengths up to 160 and even more, i.e., to provide the traffic transmission with the speed up to 1.6 Tbit/s in one direction and in single optical fiber

Real-Time Strain and Elasticity Imaging in Phase-Sensitive Optical Coherence Elastography Using a Computationally Efficient Realization of the Vector Method

We present a real-time realization of OCT-based elastographic mapping local strains and distribution of the Young’s modulus in biological tissues, which is in high demand for biomedical usage. The described variant exploits the principle of Compression Optical Coherence Elastography (C-OCE) and uses processing of phase-sensitive OCT signals. The strain is estimated by finding local axial gradients of interframe phase variations. Instead of the popular least-squares method for finding these gradients, we use the vector approach, one of its advantages being increased computational efficiency. Here, we present a modified, especially fast variant of this approach. In contrast to conventional correlation-based methods and previously used phase-resolved methods, the described method does not use any search operations or local calculations over a sliding window. Rather, it obtains local strain maps (and then elasticity maps) using several transformations represented as matrix operations applied to entire complex-valued OCT scans. We first elucidate the difference of the proposed method from the previously used correlational and phase-resolved methods and then describe the proposed method realization in a medical OCT device, in which for real-time processing, a “typical” central processor (e.g., Intel Core i7-8850H) is sufficient. Representative examples of on-flight obtained elastographic images are given. These results open prospects for broad use of affordable OCT devices for high-resolution elastographic vitalization in numerous biomedical applications, including the use in clinic