Monochromatic light for use at ultra violet wavelengths - is generated using asymmetrical rectangular system with concave reflector

摘要

Monochromatic sources at ultra violet wavelengths have been difficult to achieve because the transparency and reflective properties of the usual optical materials is poor. The use of concave asymmetrical systems processed for good reflexion overcome the difficulties enabling good focus and dispersion and also wavelength changes to be made. A monochromatic source is derived from a system comprising an input slit (F1) and an output slit (F2). The spherically concave reflector (6) rotates about its perpendicular axis on a slide (T). The reflector is connected by arms (P1, P2) articulated at a point (0') to a fixed point (B) such that movement of the point (0') describes a circle (L) about the fixed point (B). This rotates the reflector and moves it along the slide (T). Positions are determined by calculations including number of lines per millimetre engraved on the reflector.