Optical Carrier-Suppressed Single Sideband Modulation Based on a Thin-Film Lithium Niobate IQ Modulator for FMCW Ranging Application

Abstract

Optical carrier-suppressed single sideband (OCS-SSB) signals are known for their easy detection, low noise, and high energy efficiency. Here, we develop a high-performance OCS-SSB signal generation system utilizing an integrated TFLN in-phase/quadrature (IQ) modulator, along with an automatic bias control (ABC) module. Our device can achieve a side-mode suppression ratio (SMSR) surpassed 20 dB, optimally reaching up to 29.53 dB, which covers a large electrical-optic bandwidth and central wavelength range. For long-term stability, the peak–to–peak fluctuation of SMSR was measured to be 1.79 dB, with an average SMSR value of 23.47 dB for nearly 8 hours. Furthermore, we successfully demonstrate that our device can be implemented in a frequency-modulated continuous-wave (FMCW) ranging detection, allowing the standard deviation no more than ±2.60 mm. Our system offers substantial potential for direct application in various chip-scale integrated fields, including LIDAR and microwave photonics.