| 摘要 |
<p>Disclosed is an illuminating optical system which can illuminate a surface to be irradiated with light in a required polarisation state, and can limit the effect of retardation by an optical system succeeding a polarisation conversion member. The illuminating optical system (1-12) which illuminates a surface to be irradiated (M) with light from a light source (LS), is provided with: a polarisation conversion member (5A) which converts the polarisation state of incident light, and forms a pupil intensity distribution of a prescribed polarisation state on the illumination pupil of the illuminating optical system; and a phase modulation member (5B), which is disposed in the optical path further toward the surface to be irradiated side than the polarisation conversion element. In order to reduce the effect of retardation due to a succeeding optical system between the polarisation conversion member and the surface to be irradiated, of the light forming the pupil intensity distribution, the phase modulation member (5B) converts linearly polarised light which is polarised in a first direction to a required elliptically polarised light, and allows the polarisation state of linearly polarised light which is polarised in a second direction (X direction or Y direction) which obliquely intersects with the first direction, to pass through so as to be preserved.</p> |
