MIRRORED OBJECT AND MIRRORED SUBSTRATE WITH HIGH ASPECT RATIO, AND METHOD AND MEANS FOR MANUFACTURING MIRRORED SUBSTRATE

To provide a mirrored object and mirrored substrate, especially a mirrored object and mirrored substrate with a high aspect ratio, and a method and means of manufacturing them.SOLUTION: A mirrored substrate 20 comprises a material whose average linear thermal expansion coefficient is 1×10-6/K or less, preferably 0.1×10-6/K or less, most preferably 0.05×10-6/K or less. The mirrored substrate has at least one of the following characteristics: the mirrored substrate has a ratio of its lateral dimension to its maximum thickness of at least 100, preferably at least 150, more preferably at least 200, most preferably 300 or more; a mass per unit area of the mirrored substrate is 100 kg/m2 or less, preferably 50 kg/m2 or less, more preferably 30 kg/m2, and most preferably 15 kg/m2 or less. The mirrored substrate has a mirror surface with a roughness Ra of at most 3.5 μm, preferably less than 1.2 μm.SELECTED DRAWING: Figure 1 【課題】鏡面体および鏡面基材、特に高アスペクト比の鏡面体および鏡面基材、ならびにそれらを製造する方法および手段に関する。【解決手段】平均線熱膨張係数が１×１０－６／Ｋ以下、好ましくは０．１×１０－６／Ｋ以下、最も好ましくは０．０５×１０－６／Ｋ以下である材料を含む鏡面基材２０であって、前記鏡面基材は、以下の特徴：－前記鏡面基材は、少なくとも１００、好ましくは少なくとも１５０、より好ましくは少なくとも２００、最も好ましくは３００以上の、その最大厚さに対するその横寸法の比を有する；－前記鏡面基材の単位面積当たりの質量は、１００ｋｇ／ｍ２以下、好ましくは５０ｋｇ／ｍ２以下、より好ましくは３０ｋｇ／ｍ２、最も好ましくは１５ｋｇ／ｍ２以下である；のうちの少なくとも一方を有し、前記鏡面基材は、最大３．５μｍ、好ましくは１．２μｍ未満の粗さＲａを有する鏡面を有する、鏡面基材。【選択図】図１