Continuous-wave dye laser tunable by a holographic diffraction grating

An investigation was made of the parameters of a cw dye laser tunable by a holographic diffraction grating (2040 lines/mm, first-order reflection R = 85% at the wavelength of 580 nm). This grating was placed behind a semitransparent mirror and it produced an output line 10 pm wide; the use of an additional telescope reduced the line width to 2 pm. The emission wavelength was tunable over a range 20–25 nm wide (in the case of rhodamine 6 G). The emission wavelength was controlled simply by the position of the diffraction grating and the output power remained constant throughout the tuning range. For comparison, a study was made of the characteristics of a laser with a selector formed by two prisms and a Fabry–Perot etalon.