OPTICAL DEVICE FOR TWO-DIMENSIONAL EXPANSION OF SPECTRUM

PROBLEM TO BE SOLVED: To measure by a small, highly precise, and low cost device capable of excellently separating line spectral images in a wavelength direction without chromatic aberration and focusing a two-dimensionally placed beam receiver on an expanded image in the orthogonal direction to the wavelength direction in two-dimensional and highly time-resolved measurement of a series of distribution of line spectra spectroscopically separated and, longitudinally lined up. SOLUTION: Focus of an image in each direction is adjusted for the series of distribution of the line spectra spectroscopically separated and longitudinally lined up from a beam entering part 1 by a troidal mirror 2 for adjusting in orthogonal and wavelength directions. Wavelength spectral images are expanded in the wavelength direction by a cylindrical mirror 3, and the image in each direction is received by the beam receiver 5 held by a beam receiver holder. A one-dimensional beam receiver array can thereby expand dimension to two- dimension. The device is free from chromatic aberration and independent of wavelength since a lens is not used, and operability is excellent since adjustment of the focus is not required, and measuring precision is also improved. In the device shown in the figure, the image in the orthogonal direction is separated into upper and lower portions by a light branch mirror 4.