Commercial availability of astronomical machined gratings by Canon

摘要

A machining grating is remarkable for infrared use because it is difficult to get an ideal shape by traditional ruling engine. Canon has many kinds of gratings for the infrared on sale now by our processing technology. Our commercial grating is not only a conventional (reflection) grating but also an immersion grating. An immersion grating is very powerful and key device for the infrared high-resolution spectroscopy. It is sure that an immersion grating becomes next generation standard diffractive device for the infrared. However, there was no opportunity, which can be obtained easily before we enter this field. Our machined grating has very high absolute diffraction efficiency by the actual measurement. Furthermore, our surface flatness is the excellent compared before us. These are the performances already proved through our productions. Those will be the standard performance of a grating for astronomy. In this paper, we report that the performances and restrictions of machined grating in Canon.