Line narrowing unit with flexural grating mount

本发明提供一种用于对产生高能激光束的基于光栅的激光器变窄光线的变窄光线装置。提供了一种挠性光栅固定件，它真正地消除了由于光栅和壳体结构之间的不同热膨胀而导致的光栅上的应力。使用一挠性光栅固定件将在一厚的超低膨胀玻璃基片上包括一十分薄的铝制表面的光栅附接至一铝制壳体结构上。在光栅固定件中至少设置一个挠曲连接部，它允许基片热膨胀和收缩。在一些实施例中，固定件包括一金属板，所述挠曲连接部是机加工到金属板中的带有四个腿部(126)的一H形的挠曲连接部(124)。在另一实施例中，设置了两个H形的挠曲连接部。在其它的实施例中，该挠曲连接部是一鸠尾连接部，它允许固定件的一端相对另一端滑动。 A grating based line narrowing device for line narrowing lasers producing high energy laser beams. Techniques are provided for minimizing adverse effects of heat produced by the laser beam inside the line narrowing device.A flexural grating mount is provided which virtually eliminates stress on the grating caused by differential thermal expansion between the grating and the LNP housing structure. In a preferred embodiment the grating which is comprised of a very thin lined aluminum surface on a thick ultra low expansion glass substrate is attached to an aluminum housing structure using a flexural grating mount. At least one flexure joint is provided in the grating mount which permits thermal expansion and contraction of the aluminum housing without producing undesirable mechanical stresses in the glass substrate of the grating. In some embodiments the mount comprises a metal plate and the flexure joint is a H-Flex joint which is machined into the metal plate. In another embodiment two H-Flex joints are provided. In other embodiments, the flexure joint is a dovetail joint permitting one end of the mount to slip relative to the other.In another preferred embodiments a stream of gas is directed across the face of the grating. In other embodiments the effect of a hot gas layer on the face of the grating is reduced with the use of helium as a purge gas and in other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.