Overview: In order to achieve the measurement of gravitational wave signals in the millihertz frequency band, the space-based gravitational wave detection projects such as LISA, TianQin, and Taiji projects, which are based on laser interference systems, require the hardware noise floor of the interferometers to be lower than the interstellar weak light shot noise limit. This imposes stringent engineering specifications on the optical-mechanical design and the corresponding interferometer payload. This paper approaches the issue from the perspective of detection mode selection and derives the expressions of readout noise and stray light noise in the interference signal under the single detector mode and the balanced mode. Furthermore, a detailed discussion is provided on the weak-light interference process of the scientific interferometer. The results demonstrate that the balanced mode is capable of suppressing the interference phase noise caused by laser power fluctuations and backscattered stray light across multiple orders of magnitude. However, the suppression capability is constrained by the unequal splitting property of the beam combiner. To address this, a relative gain factor is introduced to compensate for the unequal splitting property of the beam combiner. Further analysis reveals that electronic gain compensation can only eliminate the impact of unequal splitting on one of the two noises rather than both simultaneously. Therefore, a balance must be struck in selecting gain compensation between the suppression of laser power fluctuation noise and stray light noise. Even with this consideration, the balanced mode still offers significant noise suppression capabilities at a magnitude difference, thus potentially reducing the engineering requirements for laser power fluctuations and telescope backscattered stray light.

对于基于叠加态涡旋光和涡旋光零差探测等传统转速测量方式，光的远距离传输和发散等原因造成的信号光衰减会导致探测系统无法准确提取信号，而涡旋光平衡探测系统可以解决这一难题，但是以往的研究对该探测系统的精度和信噪比鲜有分析，这一定程度上限制了其工程化的进展。首先将零差探测系统作为对比项，通过分析不同转速下涡旋光平衡探测系统和零差探测系统测量精度的变化情况，证明了二者均可实现高精度测量，其次通过对比在不同信号光功率下二者的信噪比(SNR)，发现了在测量微弱信号时涡旋光平衡探测系统具有明显优势；最后，通过分析不同本振光功率对信噪比造成的影响，揭示了平衡探测信噪比和本振光功率之间的关系，阐明了信噪比随本振光功率变化的原因。