Micromachines (Basel)
January 2025
To enhance the end-face coupling efficiency of lithium niobate on insulator (LNOI) chips, in conjunction with current device fabrication processes, a stepped spot size converter (SSC) based on a special outer envelope profile has been proposed and investigated. This stepped SSC can reduce the coupling loss between the LNOI waveguide and a normal single-mode optical fiber. First, the output waveguide of a mode converter was proposed and simulated, in which the mode field had the biggest overlapping integral factor with a single-mode fiber (MDF ≈ 9.
View Article and Find Full Text PDFA novel photonic-assisted multifunctional radar system was proposed and experimentally investigated. This system can simultaneously achieve frequency-doubled linear frequency modulation (LFM) signal generation, de-chirp reception, self-interference cancellation, and frequency measurement in an integrated transmit-receive radar. First, a high-frequency and broadband LO signal was obtained with photonic frequency doubling, which improved the center frequency and bandwidth of the radar detection system.
View Article and Find Full Text PDFA photonics-assisted binary/quaternary phase-coded microwave signal generator with fundamental/doubling reconfigurable carrier frequency applicable to digital I/O interfaces is proposed and has been verified by experiments. This scheme is based on a cascade modulation scheme, which is used to reconfigure fundamental/doubling carrier frequency and load the phase-coded signal, respectively. By controlling the radio frequency (RF) switch and the bias voltages of the modulator, the switching of the fundamental or doubling carrier frequency can be realized.
View Article and Find Full Text PDFElectro-optic modulators (EOMs) based on a thin-film lithium niobate (TFLN) photonic integration platform play a crucial role in loading electrical signals onto optical signals. In this paper, we proposed on-chip EOMs operating at two commercially available wavelengths of 850 and 1550 nm and successfully demonstrated rather low voltage-length products ( s) of 0.78 V·cm and 1.
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