We report our research on aluminum mirror optics for future infrared astronomical satellites. For space infrared missions, cooling the whole instrument is crucial to suppress the infrared background and detector noise. In this aspect, aluminum is appropriate for cryogenic optics, because the same material can be used for the whole structure of the instrument including optical components thanks to its excellent machinability, which helps to mitigate optical misalignment at low temperatures. We have fabricated alu- minum mirrors with ultra-precision machining and measured the wave front errors (WFEs) of the mirrors with a Fizeau interferometer. Based on the power spectral densities of the WFEs, we conrmed that the surface accuracy of all the mirrors satised the requirements for the SPICA Coronagraph Instrument. We then integrated the mirrors into an optical system, and examined the image quality of the system with an optical laser. As a result, the total WFE is estimated to be 33 nm (rms) from the Strehl ratio. This is consistent with the WFEs estimated from the measurement of the individual mirrors.

ABSTRACT
1. INTRODUCTION
2. METHOD
3. RESULTS AND DISCUSSION
REFERENCES

• Shinji Oseki(Graduate School of Science, Nagoya University)
• Shinki Oyabu(Graduate School of Science, Nagoya University)
• Daisuke Ishihara(Graduate School of Science, Nagoya University)
• Keigo Enya(Institute of Space & Astronautical Science, Japan Aerospace Exploration Agency)
• Kanae Haze(Institute of Space & Astronautical Science, Japan Aerospace Exploration Agency)
• Takayuki Kotani(National Astronomical Observatory of Japan)
• Hidehiro Kaneda(Graduate School of Science, Nagoya University)
• Miho Nishiyama(Graduate School of Science, Nagoya University)
• Lyu Abe(Laboratoire Universitaire d'Astrophysique de Nice)
• Tomoyasu Yamamuro(Optcraft)