Diffraction Gratings ruled in Metallic Films

Abstract

PROF. R. W. WOOD, of Johns Hopkins University, has recently reported¹ on the successful preparation of diffraction gratings by ruling on 'aluminized' surfaces, and predicts a bright future for this type of dispersive instrument. One of the most interesting aspects of this technique, however, is not included in his letter. Inasmuch as I participated in the conception and development of the general method of preparing and ruling evaporated films at Cornell University early in 1934, which method Prof. Wood was induced to adopt about a year later, I feel that I am in a position to offer some comments of interest.