The specific structure of heterodyne detection system confocal microscopy (HDSCM) is presented in this paper. The theoretical derivation reveals that, HDSCM has the same transverse and axial resolutions as direct detection system confocal microscopy (DDSCM). However, HDSCM has several advantages over DDSCM. First, HDSCM does not need the conjugate pinhole which is necessary in DDSCM, thereby avoiding the practical operation difficulties resulting from adjusting the pinhole position with sub-micron accuracy. Second, our calculations show that, for the case of clear optical pupil, the signal-to-noise ratio (SNR) of HDSCM can be increased by at least tens of dBs higher than DDSCM, thereby allowing a high-quality imaging for these samples with extremely low reflectivity. Third, when using pupil filtering technology to achieve super-resolution in confocal microscopy (CM), HDSCM shows a great SNR advantage, thereby guaranteeing high resolution.

本文介绍了外差检测系统共聚焦显微镜（HDSCM）的具体结构。理论推导表明，HDSCM具有与直接检测系统共聚焦显微镜（DDSCM）相同的横向和轴向分辨率。但是，HDSCM优于DDSCM。首先，HDSCM不需要DDSCM中必需的共轭针孔，从而避免了因亚微米精度调整针孔位置而导致的实际操作困难。其次，我们的计算表明，对于透明光瞳，HDSCM的信噪比（SNR）可以比DDSCM高至少几十个dB，从而可以对这些样本进行高质量成像反射率极低。第三，