Machined echelle gratings by canon

Canon has been continuously developing its own machine for precision and has the capability to obtain sufficient performance even for ultraviolet. The machined grating can realize an ideal shape without material distortion and can handle many materials. The ability to produce an ideal shape makes it possible to acquire the characteristics expected from the geometry (design characteristics) even in a classical echelle grating, and it is possible to select an apex angle that is more efficient in polarization characteristics. Canon provides the degree of freedom from a small pitch to a large pitch for infrared using the characteristics of cutting. The target material can be made of a brittle material (Germanium, InP) from a metallic reflection type, and the brittle material with a high transmittance in infrared can also be used as an immersion grating or a grism. In this paper we show particularly the influence of the apex angle with the echelle grating and introduce the machinability of the Apex angle by cutting.