An optical assembly includes: an optical element, which is transmissive or reflective to radiation at a used wavelength and has an optically used region; and a thermally conductive component, which is arranged outside the optically used region of the optical element. The thermally conductive component can include a material having a thermal conductivity of more than 500 W m.sup.1 K.sup.1. Additionally or alternatively, the product of the thickness of the thermally conductive component in millimeters and the thermal conductivity of the material of the thermally conductive component is at least 1 W mm m.sup.1 K.sup.1.

A diffractive optical element prevents degradation of the optical performance of the element due to moisture absorption of the resin layers from taking place and also can prevent cracks of the resin layers and peeling of the resin layers along the interface thereof from taking place in a hot environment or in a cold environment. The diffractive optical element comprises a first layer and a second layer sequentially laid on a substrate, a diffraction grating being formed at the interface of the first layer and the second layer, the height d of the diffraction grating, the average film thickness t1 of the first layer and the average film thickness t2 of the second layer satisfying the relationship requirements expressed by the expressions of 1.1dt150 m and 30 mt2(400 mt1d).

A projection exposure apparatus for semiconductor lithography has a mirror arrangement that is exposed to thermal loads in operation. The mirror arrangement includes a mirror carrier having an optically active surface arranged on a top surface of the mirror carrier. A cooling system is integrated into the mirror carrier. The cooling system has cooling lines through which a cooling fluid circulates. The cooling system is designed so that the thermal load introduced into the mirror carrier via the optically active surface is dissipated at least partially into a rear region remote from the top surface of the mirror carrier.

The disclosure provides a method that includes filling a cavity in a substrate with a second material, wherein the substrate includes a first material. The method also includes using galvanic and/or chemical deposition of a third material to apply an overcoating to a first surface of the substrate in a region of the cavity. The method further includes removing the second material from the cavity. In addition, the method includes, before or after removing the second material from the cavity, applying a reflective layer to the overcoating. The disclosure also provides related optical articles and systems.

A projection optical apparatus according to an aspect of the present disclosure includes an optical system that image light enters, a reflector that reflects the image light that exits out of the optical system, and an enclosure that houses the optical system and at least part of the reflector, and the reflector includes a base having a first surface on which the image light is incident and a second surface opposite from the first surface, a reflection layer provided at the first surface of the base, and a heat dissipation member provided at the second surface of the base and including a protrusion protruding from the second surface.

A method for producing a mirror of a lithography system includes providing first and second mirror parts. Cooling channels having elongate cooling channel openings in the region of a first connecting surface of the first mirror part are formed in the first mirror part, and/or cooling channels having elongate cooling channel openings in the region of a second connecting surface of the second mirror part are formed in the second mirror part. The method also includes bringing together the first and second mirror parts so that initially a partial region of the first connecting surface and a partial region of the second connecting surface come into contact and form a common contact surface. The common contact surface is enlarged by continuing to bring the first and second mirror parts together in a direction along the longitudinal extents of the cooling channel openings.

A semiconductor apparatus includes a light source, a reflection mirror, and a heat exchanger. The reflection mirror has a reflection surface configured to reflect a light of the light source and a channel behind the reflection surface. The heat exchanger is connected to the channel and configured to circulate a working fluid in the channel.

In some embodiments, a catadioptric optical system (CDOS) including a centrally obscured reflective telescope is disclosed, which includes: a telescope compartment defining a telescope space therein, a primary reflector including a central opening and a secondary reflector. The reflectors are located in the telescope compartment. The CDOS also includes a mechanism for reducing temperature gradient in the telescope space. The mechanism includes an air duct including a first opening and a second opening; a hollow enclosure including side openings and one or more airflow generation devices. The mechanism is configured for forming an air passageway between the airflow generation device and the inner telescope space via the air duct and hollow enclosure located therebetween, for reducing internal air temperature gradient in the telescope space.

An apparatus having an optical structure and ridges is described, wherein the ridges connect the optical structure to a supporting structure and wherein the optical structure is able to perform a movement in relation to a reference plane.

An apparatus and a method for cooling a digital micromirror device are disclosed. For example, the apparatus includes a digital micromirror device (DMD), a housing coupled to the DMD, wherein a first side of the housing is coupled to a bottom of the DMD and a cooling block coupled to a second side of the housing that is opposite the first side. The cooling block includes a plate that includes a plurality of openings, a diaphragm coupled to the plate, an air inlet to generate an airflow across the plate, wherein the diaphragm creates a force to move the airflow in a direction that is perpendicular to a direction of the airflow towards the second side of the housing, and an air outlet to collect the airflow.