从光学信息量的表达式出发,研究了激光光斑尺寸和探测器小孔尺寸对共焦生物芯片扫描系统的扫描分辨率及信噪比的影响,并定量分析了在获取生物芯片图像过程中,共焦扫描系统的扫描分辨率和信噪比对光学信息量的制约关系.结果表明,为了获得尽可能大的光学信息量,必须保证激光光斑尺寸小于系统的扫描分辨率,并根据激光光斑尺寸合理地选择共焦扫描系统的扫描分辨率和探测器小孔尺寸.理论分析和实验结果表明,当扫描分辨率大于扫描激光光斑的1.2倍,且探测器小孔尺寸为扫描激光光斑的1.5- 2.0倍时,系统的光学信息量较大.
Based on the formula of information capacity for an optical system, the scanning resolution and signal-to-noise ratio for biochip confocal scanning system were studied under both different laser focused spot sizes and different detector pinhole sizes respectively. The dependence of optical information capacity on the scanning resolution and the signal-to-noise ratio were also analyzed quantitatively. In order to obtain the maximum optical information capacity, the laser focused spot size should be smaller than the scanning resolution. Moreover, the scanning resolution and the detector's pinhole size should be selected reasonably according to the laser focused spot size. The experimental results show that, when the scanning resolution is 1.2 times than the laser focused spot size, and the detector's pinhole size is 1.5 to 2.0 times of the laser focused spot size, the optical information capacity of the biochip confocal scanning system is preferable.