提出了一种基于数字微镜器件(DMD)和光电倍增管(PMT)的弱光高分辨光谱测量的新方法。首先,利用基于小尺寸狭缝的分光光路将被测光光谱成像到DMD上,然后DMD微镜阵列按列依次翻转将光谱分波段投射到PMT点探测器上,最终实现对光谱的分时扫描测量。进行了与CCD光谱仪的对比实验以及不同弱光条件下的测试实验,并对系统的信噪比(SNR)特性进行了实验测试。实验结果表明,光谱测量系统的谱分辨率高达0.23nm,灵敏度可达4.6pW以下,系统的信噪比(SNR)特性比较理想。相对于传统的光谱测量方法,本文方法具有成本低、易于实现且性能稳定等优点,在弱光高分辨光谱测量领域具有较大的潜在应用价值。
In this paper,in order to realize the high-resolution spectral measurement of low light,we propose a new spectral measurement method which is based on a digital micro-mirror device(DMD)and a photoelectric multiplier tube(PMT).Firstly,the spectrum of the measured light is imaged on a DMD by the dispersive optics system based on a small-size slit.Secondly,by the rotation of the micro-mirrors of the DMD per column,the spectrum is reflected to a PMT according to the different wavelengths.Lastly,the measurement of the spectrum is achieved through the scanning mode.The contrast experiments of our method and a charge-coupled device(CCD)spectrometer are performed,and the experiments for different low light conditions are also performed.At last,the signal-to-noise ratio(SNR)experiment of the system is conducted.The results show that the spectral resolution is 0.23 nm,the sensitivity of the spectral system is less than 4.6pW,and the SNRperformance is also perfect.Compared with the conventional spectroscopy technique,this spectral measurement method has the merits of low price,easy implementation and stable performance.