## 6 Conclusions  
In this paper, based on a hybrid collision scattering process of photons and smoke particles, a fuze detector was designed for a four-channel center-symmetric emission laser structure, taking into account the three-dimensional and spatial properties of smoke clouds. By studying the collision probability and collision scattering angle when photons simultaneously collide with multiple smoke particles, a laser echo power signal model under multiple continuous-wave lasers was established. It is concluded that the collision transmission process was affected by the combined effects of the number of collisions, particle size, and the relative spatial positions of smoke particles.  
Based on various photon 3D collision types, a virtual particle simulation model was developed using Unity3D, to output the laser echo power signal and extract the target characteristics. When the characteristics of the smoke particles were varied, the simulation results showed that the target characteristics were mainly manifested as the false alarms and missed alarms caused by the difference in the amplitude of the laser echo signal. In this case, it is crucial to mitigate the impact of the number and spatial distribution characteristics of smoke particles.  
In the validation process of a four-channel center-symmetric emission laser structure, the simulation results showed that the false alarm rate in low visibility and the missed alarm in high visibility could be effectively mitigated. The experimental findings indicate that the smoke echo signal and the target echo signal were separated effectively, and the anti-smoke interference capability of the system was enhanced significantly. The average growth rate of the target echo signal amplitude was 180.2% when the visibility was increased from 5 m to 15 m. In addition, as the visibility of the smoke was increased, the ratio of the target echo signal amplitude increased rises. An improvement of 147% in the SNR was observed with an increase in the number of channels. This further underscores the superior target detection capability of the detector when employing this structure.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Smoke Visibility** & **4.8 m** & **5.7 m** & **6.2 m** \\ \hline Single-channel & \(-\)5.59 dB & \(-\)4.74 dB & \(-\)3.57 dB \\ emission laser & \(-\)8.13 dB & \(-\)5.06 dB & \(-\)0.96 dB \\ \hline \end{tabular}
\end{table}
Table 4: The results of signal-to-noise ratio for visibilities of 4.8 m, 5.7 m, and 6.2 m.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Smoke Visibility** & **Four-Channel** & **Single-Channel** & **Ratio** \\  & **Emission Laser** & **Emission Laser** & **Ratio** \\ \hline
5.7 m & 18.1\% & 55.1\% & 3.04 \\
6.2 m & 59.7\% & 274.6\% & 4.60 \\ \hline \end{tabular}
\end{table}
Table 3: Amplitude growth rate and ratio of target echo signals based on visibility of 4.8 m.  
In summary, the above contents and conclusions provide accurate and specific guidance for the optimization of multi-optical channel laser emission systems, which can further improve the anti-smoke interference and target detection performance of FMCW laser fuzes.  
Conceptualization, Z.G. and Z.H.; Methodology, Z.G.; Writing--original draft preparation, Z.G. and B.Y.; Analysis and interpretation of data, Z.G.; Writing--review and editing, Z.G.; Supervision, Z.H.; Project administration, Z.G. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
All data are contained within the article and further inquiries can be directed to the corresponding author upon reasonable request.  
The authors declare no conflicts of interest.