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In the field of ultra-high sound pressure noise environment of rocket engines, fiber laser microphones without diaphragm packaging have prominent pressure-resistant advantages. However, the phase noise problem introduced by unbalanced interferometer in engineering applications limits their performance. This paper focuses on the phase noise of the fiber laser microphone array introduced by the unbalanced interferometer in the modulation system. Firstly, the working principle of the modulation system and the source of the phase noise of the unbalanced interferometer are discussed, and a stable laser light source is incident on the unbalanced interferometer shared by the microphone system, to construct fiber laser microphone array system with suppressed optical phase noise. Then, the suppression principle is theoretically analyzed using the differential cross multiplying (DCM) demodulation. The noise information of the optical reference is used to cancel out the system noise introduced by the interferometer, thereby achieving the dynamic noise suppression. Finally, numerical simulation and experimental verification are conducted on the microphone array system. As a result, the phase noise measured in the non-equilibrium interferometer is reduced from approximately ± 0.34 rad to within ± 0.15 rad compared with the system without optical reference under field experimental conditions. The noise peak is sup-pressed by more than 7 dB, and the noise power spectral density is reduced from -25.02 dB/
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| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
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