Unidimensional and Bidimensional Beam Expander Effects on the Output Power and Spectral Bandwidth of a Dye Laser

The effect of two types of beam expanders (prismatic and telescopic) on the output intensity and band width of dye laser has been investigated. The prism beam expander is unidimensional and little cumbersome. Two prism beam expanders were tested. The first, composed of two prisms, could lead to a folded resonator; it was short and gave higher power, but with 9.6 pm bandwidth. The second prism beam expander contained four prisms as well as the resonator was longer, but it could have 0.7 pm bandwidth. Concerning the telescopic two-dimensional beam expander, four different beam expanders were used with expanding ratios: 2X, 5X, 10X and 15X. In each case, the bandwidth, the output power and the wavelength stability were investigated. The 10X telescopic beam expander was the best with 0.7 pm bandwidth and good wavelength stability over 6 h of operation.