THE "JEULIN" GRATING
I started experimenting with spectroscopy in late 2002 using a 100 lines/mm transmission grating obtained from Jeulin in France (But as I later found out, actually manufactured by Paton Hawksley in the UK). It is mounted in a 50x50mm glass slide and is blazed to increase efficiency (most of the light is diffracted into one of the first order spectra.) You can see a review of it here http://astrosurf.com/buil/us/spe1/spectro3.htm
The grating consists of two 50mm square glass slides, separated by a paper spacer and taped together. One slide is plain glass to protect the fragile grating surface. The other slide has the diffraction grating pattern affixed to it. (the grating pattern is a cast of an original ruled grating, made in a thin film of resin on the glass slide substrate)
The diffaction pattern of a blazed transmission grating produced by a monchromatic laser pointer. The right hand bright spot is the zero order (straight through) image. The left bright spot is the first order spectrum. Note the difference in brightness between the left and right hand first orders due to to the blazing.
Click here for a similar test of the higher efficiency Star Analyser grating which was subsequently developed by Paton Hawksley.
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