Virtually imaged phased array (VIPA) having lenses arranged to provide a wide beam width

摘要

An angular dispersive device acts as a virtually imaged phased array (VIPA) which receives an input light, and produces a spatially distinguishable output light in accordance with the wavelength of the input light. First, second and third lenses are arranged in order to focus the input light into the angular dispersive device. The characteristics of the first, second and third lenses are determined to provide an increased beam width in a top view of the output light produced by the angular dispersive device. The first lens collimates the input light in a side view and has no lens effect in a top view. The second lens receives the input light from the first lens, and focuses the input light in the side view and has no lens effect in the top view. The third lens receives the input light from the second lens, and collimates the input light in the top view and has no lens effect in the side view. The angular dispersive device has first and second surfaces. The first and second lenses can be combined into a single lens.