2008-02-22

First spectra by SGS

Last year, we purchased the SGS spectrograph. I spend today's afternoon by acquainting myself with the device. First images looks really amazing. All ones has been acquired in my office with a scattered radiation of a fluorescent lamp as a light source with our new ST-8 XME camera as a detector. Compare my findings with its spectrum.

An image of a spectrum of fluorescent lamp in low-resolution mode of SGS. The wavelength interval is about 300 - 900 nm. Ultraviolet is on the left, red is on the right.

An image acquired in high-resolution mode. Wavelengths in interval 490 - 650 nm. The orientation is the same as in previous case. The image covers approximatelly central quarter of the low-resolution spectra (try find of Tb - Eu series between two strong lines).

The image of the same lamp acquired by a digital camera (Canon EOS 30D) and a simple CD spectrograph for comparison. You can simply identify global spectral features. The strong red line corresponds to the strong line on the right on high-res image of spectra. The green line is the strong line on the left of the same image. The lighter horiznotal line has been used for construction of a first graph on image below.

A calibrated graphs of spectra of the images above (click for original size). Top to bottom: spectrum by CD's "grating", low-resolution of SGS, high-resolution of SGS. The graphs exhibits different spectral resolution of all "instruments" (look on series of Tb and Eu at 570-600 nm) and different spectral sensitivity (color graphs, line at 550nm).

Once, the spectra looks really fine, I'v worries about simple use of our equipment. The CCD can be connected to spectrograph only without filter wheel (due to focusing range) but the removing of the wheel is really complicated and delicate operation.

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