| 摘要 |
<p>A durable etalon based laser output coupler for ultraviolet lasers such as an ArF excimer laser or an F2 laser has two prisms (164A, 164B) aligned so that a first surface of one prism is parallel to a first surface of the other prism. The first prism has a second surface forming an angle with a beam from a laser cavity approximately equal to Brewster's angle. The second prism has a second surface forming an angle with the coupler exit beam approximately equal to Brewster's angle. For a wavelength of 193 nm, in an ArF excimer laser, Brewster's angle is about 57 degrees and each of the first and second surfaces define an apex angle of about 34 degrees. In a preferred embodiment, the device is used as an output coupler for line narrowed ArF excimer laser (63) having a diffraction grating based line narrowing module.</p> |
