Olympus Optical Company, Ltd.

Hitoshi Ohashi

Yasuhiro Kamihara

Ayami Imamura

An illumination optical system for cutting infrared light by a relief type optical element includes a light source and a relief type diffraction optical element having a rectangular sectional-shaped grating having an equal area of land and groove areas so that primarily zero order light can be used for illumination while higher order and infrared light may be filtered out. A relief pattern has characteristics such that a ratio .beta. of a width of a plurality of respective concave portions to a pitch of adjacent convex portions is in a range of 0.34.ltoreq..beta..ltoreq.0.66 and a groove depth d is in a range of 0.85 d.sub.0 .ltoreq.d.ltoreq.1.09 d.sub.0. Excessive heat from infrared light and higher order light may be eliminated without the use of an infrared cutter.

Illuminating optical system for cutting infrared light by relief type

An illuminating optical system for use in a projection exposure device with high utilization efficiency of the light from the light source and capable of easily realizing with simple construction is disclosed. The system comprises a light source, a light flux separating optical system for separating a light flux from the light source, a condenser optical system for leading the light flux separated by the light flux separating optical system on a reticle, and a diffraction optical unit included in the light flux separating optical system and having a linear grating pattern for separating the light flux from the light source into four.

Illuminating optical system for use in projecting exposure device

Methods of manufacturing optical elements such as diffraction type lenses, aspherical lenses and diffraction gratings are disclosed. Deposited on a glass substrate is a workpiece film made of a material which can be machined much more easily than the substrate. Then the workpiece film is machined to form a predetermined shape or contour therein. After forming the predetermined shape or contour in the workpiece film, the workpiece film and substrate are subjected to etching to duplicate the predetermined shape or contour formed in the workpiece film into the substrate.

Method of manufacturing optical element

A method of manufacturing a die for optical elements having a given construction on a relief type grating or the like is disclosed. The method includes the steps of: forming a workpiece film on a substrate; machining the workpiece film in a required configuration; subjecting the workpiece film machined in the required form and the substrate to etching to transfer the configuration of the workpiece film on the substrate analogously in the depth direction; and forming a die by using the etched substrate as a master matrix.

Method of manufacturing die and optical element performed by using the

An optical system for use in a relatively wide wavelength range including a plurality of diffractive optical elements whose diffraction efficiencies are optimized for different wavelengths within said predetermined wavelength range. A diffractive optical element for use in a wide wavelength range includes a light transmissive substrate having a plurality of surface regions and a plurality of surface relief diffractive gratings are formed in said surface regions such that diffraction efficiencies of these gratings are optimized for different wavelengths within said predetermined wavelength range. A diffractive optical element is formed by a single optical element having a light transmissive substrate which reveals a given spectral transmittance and a surface relief diffractive grating formed in a surface of said substrate such that a wavelength dependency of said grating provides a desired spectral transmittance together with said spectral transmittance of the substrate.

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Hachioji, Japan

Hitoshi Ohashi