A system is described which modifies a scanning spectrometer for the visible and the near ir in a simple manner for double beam operation, particularly for use with small samples. The apparatus utilizes a split pupil of a collimator in conjunction with a rotating sector to separate the two partial beams. The operation of the modulator and the electronic circuitry are discussed in detail. The system offers the advantage of simple construction with a high degree of compensation of the optical path lengths, and particularly, with close proximity of probe and reference specimen.
© 1971 Optical Society of America
Original Manuscript: September 28, 1970
Published: January 1, 1971
K. Leutwein, "A Simple Double Beam Accessory for Absorption Spectroscopy," Appl. Opt. 10, 46-50 (1971)