Performance of a thinned back-illuminated CCD coupled to a confocal microscope for low-light-level fluorescence imaging

摘要

Abstract: This paper describes the results of coupling a Tektronix TK512 CCD imager to a Technical Instruments K2Bio Nipkow disk real-time confocal microscope. The characteristics of the selected TK512 CCD imager are as follows: the chip is a thinned, back-illuminated device which has an anti-reflection coating. The quantum efficiency of the device is 86.4% at 400 nm. The CCD imager is a TK512, silicon CCD which is sensitive from the UV to the near-IR. The sensor is a full-frame area imager, with CCDs fabricated using a buried channel, three-level polysilicon gate process with very high charge-transfer efficiency ($2 $GRT 0.9999) and low dark current. Low noise on-chip amplifiers provide and interface to external preamplifiers with readout noise typically $LS@10 electrons at $MIN@90$DGR@C, and 50 kpixels/sec data rate. The CCD device is mounted in a Photometrics liquid-cooled CCD camera. The camera system operates at 14 bits and the readout rate is 50 kpixels per second. The confocal microscope is based on a one-sided Nipkow disk design with a 100 W mercury arc as the light source. The object is a freshly enucleated rabbit eye. Charge- coupled devices (CCD) have several advantages over tube camera imaging devices. These advantages include: geometric stability, high dynamic range (12, 14, or 16 bits) and photometric linearity. The use of CCD imaging devices together with real-time Nipkow disk confocal microscopes is a solution to the low light levels that are detected.!