Polarization-Multiplexed Chaotic LiDAR Based on a VCSEL with Delayed Orthogonal Feedback

Abstract

Light detection and ranging (LiDAR) systems are pivotal for precise distance and velocity measurement, yet widespread deployment requires solutions that balance their performance, robustness, and simplicity. Here, we propose a novel chaotic LiDAR system based on a semiconductor vertical-cavity surface-emitting laser (VCSEL) with delayed orthogonal polarization feedback. By exploiting the intrinsic competition between the transverse electric (TE) and transverse magnetic (TM) modes, the system generates a polarization-multiplexed dynamics: a chaotic TM mode serves as the reference, while a feedback-modulated TE mode probes the target. This all-in-one source eliminates the need for external optical modulators or complex coherent detection. The system's dynamics is finely tunable via a half-wave ($λ$/2) plate in the feedback loop and the laser injection current, enabling real-time optimization of the cross-correlation signal-to-noise ratio. Experimental results demonstrate precise linear ranging with a resolution of approximately 1.2 cm. Furthermore, the system exhibits strong inherent resistance to external optical interference, maintaining accurate ranging even in the presence of a secondary laser source. This compact, tunable, and interference-resilient platform offers a promising pathway toward low-cost, high-performance LiDAR for applications in autonomous navigation, robotics, and industrial metrology.

Figures (6)

• Figure 1: Experimental setup of the chaotic LiDAR system: reconfigurable source (transmitter) and receiver modules. In the transmitter, VCSEL, Vertical Cavity Surface Emitting Laser; BS, beam splitter; PBS1, polarized beam splitter; M1, M2 and M3, mirrors; $\lambda/2$, half-wave plate; RC, rotation controller. In the receiver stage, ISO, optical isolator; PD1 and PD2, photodetectors; PC, personal computer.
• Figure 2: Static and dynamic characterization of the VCSEL under free-running and delayed orthogonal feedback conditions: (a) Light-current (L-I) curves for the total output (black) and the individual TE (red) and TM (blue) polarization modes; (b) and (c) Radio-frequency (RF) spectra of the (b) TE and (c) TM modes for the free-running laser at $J = 1.64$ mA; (d)–(f) Dynamics of the TE mode under orthogonal feedback: (d) temporal trace, (e) corresponding RF spectrum and (f) autocorrelation function. (g)–(i) Dynamics of the TM mode under the same feedback: (g) time series, (h) RF spectrum, and (i) autocorrelation function.
• Figure 3: Cross-correlation characterization of the chaotic LiDAR system. (a) CCF between the TE and TM polarization modes under orthogonal feedback. CCF between the TE and TM polarization modes when a target echo is detected.
• Figure 4: Linearity, resolution, and tunability of the chaotic LiDAR system. (a) Measured time shift of the anti-correlation peak as a function of target distance; (b) Fine displacement measurements; (c) Amplitude of the cross-correlation anti-correlation peak as a function of the $\lambda$/2-plate angle
• Figure 5: Tunable operating regimes of the chaotic LiDAR system via current and polarization control: (a) $J = 2.10$ mA; (b) $J = 5.76$ mA.