Abstract: A method of forming an optical device comprises applying a laser beam to a target area of the surface so as to selectively heat material of the surface thereby to provide transfer of material due to a surface tension gradient, wherein the surface is such that, when liquid, parts of the surface at higher temperatures have a higher surface tension than adjacent parts of the surface at lower temperatures.

Abstract: A measurement scale device includes at least one scale marking, wherein the or each scale marking includes at least one periodic nanostructure that represents scale device information.

Abstract: The invention provides a rotary device comprising a first rotor rotatable about a first axis and having at its periphery a recess bounded by a curved surface, and a second rotor counter-rotatable to said first rotor about a second axis, parallel to said first axis, and having a radial lobe bounded by a curved surface, the first and second rotors being coupled for intermeshing rotation, wherein the first and second rotors of each section intermesh in such a manner that on rotation thereof, a transient chamber of variable volume is defined, the transient chamber having a progressively increasing or decreasing volume between the recess and lobe surfaces, the transient chamber being at least in part defined by the surfaces of the lobe and the recess; the ratio of the maximum radius of the lobe rotor and the maximum radius of the recess rotor being greater than 1.

Abstract: A measurement scale device includes at least one scale marking, wherein the or each scale marking includes at least one periodic nanostructure that represents scale device information.

Abstract: A method of applying a marking onto a metrological scale. The method includes locating one or more markings on the scale substrate in a provisional state; checking whether the one or more markings located on the scale substrate are acceptable; and finalizing the one or markings which are acceptable so as to transform the one or more markings into a finalized state.

Abstract: A rotary device includes a first rotor rotatable about a first axis and having at its periphery a recess bounded by a curved surface, and a second rotor counter-rotatable to the first rotor about a second axis, parallel to the first axis, and having a radial lobe bounded by a curved surface, the first and second rotors being coupled for intermeshing rotation, wherein the first and second rotors of each section intermesh in such a manner that on rotation thereof, a transient chamber of variable volume is defined, the transient chamber having a progressively increasing or decreasing volume between the recess and lobe surfaces, the transient chamber being at least in part defined by the surfaces of the lobe and the recess; the ratio of the maximum radius of the lobe rotor and the maximum radius of the recess rotor being greater than 1.

Abstract: A measurement scale device includes at least one scale marking, wherein the or each scale marking includes at least one periodic nanostructure that represents scale device information.

Abstract: A method of reading data represented by a marking including at least one periodic nanostructure, the marking representing data using a polarisation property of the periodic nanostructure. The method includes detecting polarised electromagnetic radiation reflected from or transmitted by the nanostructure, and determining the data represented by the marking from the detected polarised electromagnetic radiation, wherein the method further includes applying polarised electromagnetic radiation to the nanostructure, and/or the detecting is performed using a polarisation-sensitive detector apparatus.

Abstract: A method of applying a marking onto a metrological scale. The method includes locating one or more markings on the scale substrate in a provisional state; checking whether the one or more markings located on the scale substrate are acceptable; and finalising the one or markings which are acceptable so as to transform the one or more markings into a finalised state.

Abstract: A method of applying a marking onto a metrological scale. The method comprises locating one or more markings on the scale substrate in a provisional state; checking whether the one or more markings located on the scale substrate are acceptable; and finalising the one or markings which are acceptable so as to transform the one or more markings into a finalised state.

Abstract: A method of forming an optical device comprises applying a laser beam to a target area of the surface so as to selectively heat material of the surface thereby to provide transfer of material due to a surface tension gradient, wherein the surface is such that, when liquid, parts of the surface at higher temperatures have a higher surface tension than adjacent parts of the surface at lower temperatures.

Abstract: A rotary device includes a first rotor rotatable about a first axis and having at its periphery a recess bounded by a curved surface, and a second rotor counter-rotatable to the first rotor about a second axis, parallel to the first axis, and having a radial lobe bounded by a curved surface, the first and second rotors being coupled for intermeshing rotation, wherein the first and second rotors of each section intermesh in such a manner that on rotation thereof, a transient chamber of variable volume is defined, the transient chamber having a progressively increasing or decreasing volume between the recess and lobe surfaces, the transient chamber being at least in part defined by the surfaces of the lobe and the recess; the ratio of the maximum radius of the lobe rotor and the maximum radius of the recess rotor being greater than 1.

Abstract: A method of applying a marking onto a metrological scale. The method comprises locating one or more markings on the scale substrate in a provisional state; checking whether the one or more markings located on the scale substrate are acceptable; and finalising the one or markings which are acceptable so as to transform the one or more markings into a finalised state.

Abstract: An optical element has a member having features which interact with incident light to produce two or more resultant beams. The configuration of the optical element is such that light which interacts with said features when passing through the member from a first side to produce two or more resultant beams does not interact with said features when returned to another side of the member and/or vice versa. The optical element may be used in a readhead of a scale and readhead apparatus.