Investigation of the possibility to compensate for the blooming effect in CCD optical spectral sensors

Abstract

The multipixel semiconductor light sensors are becoming more and more popular in the spectroscopy practice. But insufficient for the spectroscopy dynamic range and nonlinearity of such sensors are well known. The described experiment shows nonlinearity of the sensor starting from certain light level. The role of blooming effect is shown on different complex spectral reliefs. The aim of this work was to carry out comparative studies of the dynamic range of sensors depending on the presence of anti-blooming, as well as to develop ways to expand the dynamic range during spectrophotometric measurements. Based on common sense and the analysis of previous experiments it is reasonable to assume that registration of the same spectral region with bidirectional transportation of charges in CCD devices could give extra advantages for the following linearization. In order to investigate the problem, a camera was created that allows recording the same plots of the spectrum with pairs of detector lines with the opposite direction of charge transport in charge-coupled devices (CCD). The paper presents a description of the technical solutions used in the development of the camera and the results of measurements of real emission spectra. The methods for processing data recorded during such spectrum registering are proposed. The possibility of a significant expansion of the dynamic range in the field of large signals is shown. The results of the experiment prove the possibility of using the proposed method for linearization of over-illuminated spectral line images. The comparison of the non-linearity of several types of sensors with different anti-blooming capabilities was performed. The described technology may be used for developing multisensor CCD spectral cameras.

Keywords

• charge coupled devices
• ccd
• blooming effect
• nonlinear distortion
• dynamic range
• reciprocity law