ABSTRACT
We report results from spectral measurements in the optical and near infrared region performed with a Fourier transform wavemeter. Characteristics of a variety of lasers and the performance of the wavemeter have been studied. The group of cw lasers measured in this work is comprised of a 1550-nm multimode diode laser, an 820-nm single-mode diode laser, a 594.5 nm dye laser, and He-Ne lasers at wavelengths of 1523, 633, and 543 nm. The Fourier transform wavemeter is powerful in multimode laser investigations and in long-term frequency stability determinations. The measurements show that the wavemeter also easily reveals very low power laser modes; it is suitable for the investigation of the single-mode purity of lasers. The line position uncertainty <10(-8) can be concluded in the measurements with polarization-stabilized 633- and 543-nm He-Ne lasers.