The Rhodamine-6G dye laser which is composed of a telescope beam expender(X20), λ/2 plate, and a grazing incidence grating with a tuning mirror(GIM) is designed and fabricated. The electric field is rotated to be P-polarized with respect to the grating by inserting the λ/2 plate between the telescope and the grating in order to obtain a high grating efficiency.
When the total power of 300 μJ of the 2nd harmonic wave of $Nd^{+3}$-YAG laser is used to pump the present dye laser, the linewidth and energy conversion efficiency are measured to be 7GHz and 15%, respectively.
By inserting an intracavity tilted etalon (free spectral range: 20GHz, finess: 9, tilted angle: 25mrad) into the cavity, the linewidth is further reduced but the energy is less than 1 μJ. When the 10% (30 μJ) output energy of the 2nd harmonic wave of $Nd^{+3}$-YAG laser is used for pumping the oscillator and 90%(270 μJ) energy for pumping the amplifier, the linewidth down to 370MHz and the output energy up to 15μJ (total energy conversion efficiency: 5%) are obtained.
