Abstract: There is provided a lighting module of the type having a solid-state light source, in particular a LED, a supporting plate, and a lens; the lens has a recess housing the light source; the lens is supported by and projects from the plate by means of supporting members carried by the lens and for fitting the lens directly to the plate; and the supporting members are formed in one piece with the lens, and are spaced apart and separated from one another by cooling windows.

Abstract: An objective optical element of an optical pickup apparatus has a magnification m1 satisfying the following formula for a light flux of the wavelength ?1:?1/7?m1??1/25 and |m1 |<|M1, where M1 is an optical system magnification from the first light source to the first optical information recording medium for a light flux of the wavelength ?1. The objective optical element comprises a common region and an exclusive region. The exclusive region includes an exclusive diffractive structure having a function to suppress an increase of spherical aberration due to a raise of atmospheric temperature. A light flux of a wavelength ?2. having passed through the exclusive diffractive structure intersects with the optical axis at a position different from the position of the converged light spot formed on the information recording plane of the second optical information recording medium.

Abstract: The first and second materials of the diffraction element are selected such that the first material's refraction indexes n1(?1), n1(?2) and n1(?3) for the first, second and third wavelengths ?1, ?2 and ?3 and the second material's refraction indexes n2(?1), n2(?2) and n2(?3) for the first, second and third wavelengths ?1, ?2 and ?3 satisfy one of the conditions (1) or (2).

Abstract: An optical head is provided that increases the light utilization efficiency and that can be adapted to high-speed recording and double-layer disks. A beam-shaping lens that shapes an elliptical beam emitted from a light source into a substantially circular beam has a pair of cylindrical surfaces that are curved in the same direction. The cylindrical surface that is closer to the light source is an aspherical surface, and the cylindrical surface that is closer to the light source is a spherical surface. Thus, an optical head is obtained, with which aberrations can be kept low, even when the beam-shaping magnifying power is about a factor 2.

Abstract: A method of manufacturing an optical element, such as an objective lens, by heat-softening optical glass and press molding it with high precision in a pressing mold. The method comprises press-molding a molding material with a pressing device, comprising a pair of molds with prescribed shape, to make a molded article, measuring an optical property of the molded article, correcting pressing rate of at least one of the pressing molds based on the optical property thus measured, and further press-molding to make a molded article with the corrected pressing rate. The device has a means of driving one of the pair of pressing molds at a prescribed rate, a means for detecting an optical property, a shape or a number of the molded articles, and a means for controlling driving of the means of driving by correcting pressing rate of the molds based on the detected property, shape or number.

Abstract: Imaging systems, in particular a projection objectives of a microlithographic projection exposure apparatus, are provided. The imaging systems can have an optical axis and produce an image field which is extra-axial relative to the optical axis. The imaging systems can include a first optical element which causes a first distribution of the retardation in a plane that lies perpendicular to the optical axis, and at least one second optical element which causes a second distribution of the retardation in a plane that lies perpendicular to the optical axis. The second distribution of the retardation can at least partially compensate the first distribution of the retardation. The first and the second optical elements can be designed without rotational symmetry relative to the optical axis.

Abstract: An objective optical element for use in an optical pickup apparatus comprises a first optical surface including a first diffractive structure which comprises a plurality of concentric ring-shaped diffractive zones having a center on the optical axis and stepped surfaces arranged to be almost parallel to the optical axis and connecting respective neighboring ring-shaped diffractive zones; and a second optical surface including a second diffractive structure which comprises a plurality of concentric ring-shaped diffractive zones having a center on the optical axis and stepped surfaces arranged to be almost parallel to the optical axis and connecting respective neighboring ring-shaped diffractive zones. The stepped surfaces of the first diffractive structure are arranged to face an optical axis side, and the stepped surfaces of the second diffractive structure are arranged to face an opposite side of the optical axis side.

Abstract: The present invention relates to a device for reading from and/or writing to optical recording media, having a light source for producing a scanning beam for scanning the optical recording medium, detection means for detecting the beam influenced by the optical recording medium, and an optical element arranged in the optical beam path by means of a holder. The optical element has in a plane perpendicular to the axis of the beam path outer boundary lines inclined to one another in such a way as to enable a unique orientation. The holder has a cutout with correspondingly inclined inner boundary lines.

Abstract: An optical module has a first light source which emits a first light beam from a first light emission point in a predetermined direction, a second light source which emits a second light beam from a second light emission point in the predetermined direction, and an optical element. The optical element includes a plurality of reflection surfaces for reflecting the first and second light beams, and finally outputting the first and second light beams in the predetermined direction with a separation between the first and second light beams smaller than a distance between the first and second light emission points.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: A focusing lens for an LED is provided.

Abstract: The multi-wavelength lens for condensing a plurality of kinds of monochromatic light by refraction is disclosed. The lens comprises a common use area for all monochromatic light on at least one lens surface, the area sectioned into a plurality of aspherical zones each of which having a different refractive power; and step portions, each of which formed between adjacent aspherical zones of the plurality of aspherical zones and having a step height Dj (j=1,2,3,4, and so on, in order of closeness to a lens optical axis) in a direction parallel to the lens optical axis. At least half of the step portions satisfy a following formula when a minimum value and a maximum value of Aij for each wavelength ?i are MIN(Aij) and MAX(Aij), respectively: MAX(Aij)/MIN(Aij)<3 where, Aij=absolute(Bij?mij), Bij=(absolute(Dj))*(ni?1)/?i?C, ni is a refractive index of a lens for a wavelength ?i, mij is an integral number closest to Bij, and C is a corrective term.

Abstract: There is provided an objective lens for an optical pick-up. The objective lens is formed to be a single-element plastic lens having a first surface and a second surface. The first surface is configured to have, within an effective diameter, an inflection point at which a second derivative of a sag of the first surface takes a value of 0. Further, the objective lens having a numerical aperture larger than or equal to 0.75.

Abstract: The invention relates to a beam shaping system for providing a square or rectangular laser beam having a controlled intensity profile (uniform, super gaussian or cosine corrected for example) from an incident non-uniform beam intensity profile laser beam source (a Gaussian profile, a profile with astigmatism or any non-rotationally symmetric and non-uniform profile for example). The beam shaping system uses a first acylindrical lens for shaping the incident laser beam along a first axis and a second acylindrical lens orthogonally disposed relative to the first acylindrical lens and for shaping the incident beam along a second axis. The thereby provided light beam is a rectangular beam having a controlled intensity distribution in the far field.

Abstract: There is provided an objective lens used for a plurality of types of optical discs having a front surface and a rear surface, each of which includes an inner region and an outer region. The outer region has a surface shape which suppresses a coma caused when a beam used for a first optical disc is incident thereon obliquely with respect to an optical axis of the objective lens. The inner region is configured such that, at a boundary position between the inner region and the outer region, the coma caused when a beam used for a second optical disc is incident on the inner region obliquely at a first angle with respect to the optical axis is less than the coma caused when the beam used for the second optical disc is incident on the outer region obliquely at the first angle with respect to the optical axis. Further, an inclination ?2A of the inner region and an inclination ?2B of the outer region of the rear surface satisfy a condition: ?2.5<?2B??2A<0.0 . . . (1).

Abstract: A lightweight, compact image projection module, especially for mounting in a housing having a light-transmissive window, is operative for causing selected pixels in a raster pattern to be illuminated to produce an image of high resolution of VGA quality in color.

Abstract: Imaging systems, in particular a projection objectives of a microlithographic projection exposure apparatus, are provided. The imaging systems can have an optical axis and produce an image field which is extra-axial relative to the optical axis. The imaging systems can include a first optical element which causes a first distribution of the retardation in a plane that lies perpendicular to the optical axis, and at least one second optical element which causes a second distribution of the retardation in a plane that lies perpendicular to the optical axis. The second distribution of the retardation can at least partially compensate the first distribution of the retardation. The first and the second optical elements can be designed without rotational symmetry relative to the optical axis.

Abstract: An image pickup lens assembly comprises three lens groups, from the object side to the image side: a first lens group, a second lens group, and a third lens group. The first lens group includes two lenses with refractive power, namely, a first lens with positive refractive power, and a second lens with negative refractive power. The front surface of the first lens is convex, and the rear surface of the second lens is concave. The second lens group includes a meniscus third lens with positive refractive power, the rear surface of the third lens is convex. The third lens group includes a fourth lens with negative refractive power, the front surface of the fourth lens is convex, and the rear surface of the fourth lens is aspheric. An aperture stop is located between the first lens and the second lens of the first lens group for controlling the brightness of the optical system.

Abstract: An optical system (20) for efficiently collimating an elliptical light beam includes a light source (21), a collimator (22), and at least one prism (23,24). The light source is adapted for providing an elliptical light beam defining different diverging angles in different directions, wherein any cross-section of the elliptical light beam emitted from the light source defines a long axis and a short axis which are perpendicular to each other. The at least one prism is used for reconfiguring the elliptical light beam, thus obtaining a parallel round light beam having equivalent short axis and long axis.

Abstract: An objective lens is included in an optical pickup device that records and/or reproduces an information signal onto and/or from an optical recording medium. The objective lens has a numerical aperture of 0.82 or higher, has first and second surfaces that are both aspherical, and focuses a light beam onto the optical recording medium. The first and second surfaces have surface-to-surface eccentricity therebetween that causes an aberration, the aberration being correctable by tilting an optical axis of the objective lens relative to a central axis of the light beam incident on the objective lens. The aberration caused by the surface-to-surface eccentricity includes a third-order coma aberration. When the optical axis is tilted relative to the central axis of the incident light beam so that the third-order coma aberration becomes substantially 0 m? rms, each of astigmatism, spherical aberration, and high-order coma aberration becomes 20 m? rms or less.

Abstract: An optical pickup apparatus for conducting at least recording or reproducing of information on two types of optical information recording media having protective substrates with different thicknesses, includes: a first light source for emitting a first light flux with a wavelength ?1; a first objective lens for converging the first light flux on an information recording surface of a first optical information recording medium when the optical pickup apparatus reproduces or records information for the first optical information medium; and a second objective lens for converging the first light flux on an information recording surface of a second optical information recording medium when the optical pickup apparatus reproduces or records information for the second optical information medium, wherein effective diameters of the first objective lens and the second objective lens are substantially same.

Abstract: An objective optical system according to the present invention is provided for use in an optical pickup apparatus for recording or reproducing information on an information recording surface of a first optical information recording medium using a first light flux emitted from a first light source, and the objective system includes: a first lens with a positive reflective power including plastic; and a second lens with a positive refractive power including plastic. Opposite optical surfaces of the first lens are convex surfaces, and a refractive power of the first lens and a power of a whole system of the objective optical system satisfy the predefined condition.

Abstract: There is provided a lighting module of the type having a solid-state light source, in particular a LED, a supporting plate, and a lens; the lens has a recess housing the light source; the lens is supported by and projects from the plate by means of supporting members (25) carried by the lens and for fitting the lens directly to the plate; and the supporting members are formed in one piece with the lens, and are spaced apart and separated from one another by cooling windows.

Abstract: Lens aberration in an objective lens for recording and reproducing optical information, which is composed of a molded aspherical single lens, is inhibited while at the same time good lens productivity is attained. Also attained are excellent optical properties and high production efficiency in a mold processing step and a press molding step conducted to manufacture the lens. To this end there is provided an objective lens 1 having a convex aspherical surface formed at a first surface and a numerical aperture NA which satisfies the condition NA?0.8. It is preferable to have an aspherical surface also at the second surface.

Abstract: An optical pickup includes at least a laser light source emitting a laser beam, a collimator lens system including a plurality of lenses for collimating the light beam emitted from the laser light source and incident thereupon as diffused light, and an objective lens. The laser beam transmitted through the collimator lens system is incident upon the objective lens. The collimator lens system includes a first lens unit held so as to be movable in an optical axis direction of the laser beam and a fixed second lens unit.

Abstract: In a method of manufacturing a glass optical element by press-forming a glass material in a chamber by using a forming mold comprising upper and lower dies at least one of which is movable, where a surrounded space is formed between the glass material and at least one of the upper and the lower dies when the upper and the lower dies come into contact with the glass material, a pressure within the chamber is reduced before the glass material placed in the forming mold is heated to a press-forming temperature. After sealing the space as formed when the glass material is in contact with at least one of forming surfaces of the upper and the lower dies, a gas is introduced into the chamber. The glass material is heated in the gas and then press-formed under a pressing load.

Abstract: An objective lens unit for use in an optical pickup apparatus, includes a first optical element arranged opposite to the optical information recording medium; a second optical element arranged at a light source side of the first optical element opposite to the first optical element and including a ring-shaped structure in which plural ring-shaped zones are formed on at least one optical surface of the second optical element such that neighboring ring-shaped zones cause a predetermined optical path difference for incident rays; and each of the first and second optical elements having a optical functional section and a flange section formed around the optical functional section, wherein the flange section of the first optical element and the flange section of the second optical element are formed so as to fix the first and second optical elements at predetermined respective relative positions.

Abstract: A method is provided for manufacturing a high-precision mold whereby a feature matching a desired feature design is carved into a hard mold material (41) using, for example, a diamond grinding wheel and/or a diamond turning point. Inherent imprecision and errors (49) introduced by the use of the grinding wheel/turning point are measured to determine deviations from the desired feature design. An ultrafast shortpulse laser is then activated to desirably ablate the deviations, thereby correcting the errors and conforming the feature to the desired shape. Furthermore, a thin film (1602) may be formed over the feature either prior to or after the laser ablation process, where the error measurement and laser ablation processes detects and ablates errors on the surface of the thin film, respectively. Additionally, the laser ablation process may be applied directly to, for example, an optical lens (1400) formed from an imprecise mold to remove any errors and imperfections thereon.

Abstract: In a thin beam directional Crystallization System configured anneal a silicon layer on a glass substrate uses a special laser beam profile with an intensity peak at one edge. The system is configured to entirely melt a spatially controlled portion of a silicon layer causing lateral crystal growth. By advancing the substrate or laser a certain step size and subjecting the silicon layer to successive “shots” from the laser, the entire silicon layer is crystallized. The lateral crystal growth creates a protrusion in the center of the melt area. This protrusion must be re-melted. Accordingly, the step size must be such that there is sufficient overlap between successive shots, i.e., melt zones, to ensure the protrusion is melted. This requires the step size to be less than half the beam width. A smaller step size reduces throughput and increases costs.

Abstract: There is provided an optical pickup system which includes a first light source emitting first light having a wavelength ?1, a second light source emitting second light having a wavelength ?2 longer than the wavelength ?1, a third light source emitting third light having a wavelength ?3 longer than the wavelength ?2, and an objective lens focusing the first light on an information recording surface of a first optical recording medium, focusing the second light on an information recording surface of a second optical recording medium, and focusing the third light on an information recording surface of a third optical recording medium. In the optical pickup system, at least one lens surface of the objective lens is divided into a plurality of concentric sections with an optical axis, having a step at each boundary between the sections, each of the sections has a different aspherical shape and m1>m2>0 and ?0.060?m3??0.

Abstract: A lightweight, compact image projection module, especially for mounting in a housing having a light-transmissive window, is operative for causing selected pixels in a raster pattern to be illuminated to produce an image of high resolution of VGA quality or higher in color. A laser beam focusing arrangement aligns a mechanical axis of a focusing lens with an optical axis along which a laser beam is directed to reduce pointing errors.

Abstract: There is provided an ophthalmologic apparatus that prevents ghost light from generating. In the ophthalmologic apparatus, on an optical path commonly used for an eye fundus illumination optical system and an image taking optical system including an image taking diaphragm, an objective lens for forming an image of the image taking diaphragm onto an anterior ocular segment of an eye to be examined is provided. The objective lens is formed such that the entire light beam from the center of the image taking diaphragm is substantially perpendicularly incident thereon. The objective lens is a refractive index distributed lens in which a refractive index is high in a vicinity of an optical axis and reduces as a distance from the optical axis increases.

Abstract: An optical unit of a laser module is installed at front end of a laser diode of a drive circuit board. The optical unit includes a sleeve that is integrally injection molded from plastic material. Moreover, an optical lens is formed at the top of the sleeve. The inner wall of the sleeve is provided with a focus adjusting slope facing the laser diode. In this way, the problems of the prior art with respect to the high material and assembly cost can be resolved by the invention. In other words, the invention ensures the simplification of elements and the reduction of material and assembly cost.

Abstract: As an object lens for an optical pickup, applied is a single-lens and both-side-convex configuration is applied. Further, specific conditional formulas are created with respect to a particular numerical aperture NA, for a paraxial curvature radius R1 on the surface on the light source side; the working distance WD, the refractive index nd with respect to the d-line, and the focal length f. Furthermore, specific conditional formulas are created for the refractive index nd with respect to the d-line and the Abbe's number ?d.

Abstract: A light beam emitted from a light source is focused by an objective lens onto an information recording surface of an optical information recording medium. The objective lens has a substantially truncated-cone-shaped portion on its surface on the side of the optical information recording medium. This makes it possible to prevent interference with a DVD-RAM cartridge and ensure optical compatibility with a BD and a DVD.

Abstract: An optical pickup device comprises a light source to emit a light flux having wavelength ?; an objective lens including at least two plastic lenses of a first plastic lens having positive refractive power and a second plastic lens having positive refractive power, wherein the first plastic lens and the second plastic lens are arranged in this order from the light source side; and an actuator to drive the objective lens; wherein the objective lens satisfies the following expression (1-1): ?0.0004<?3SA/(NA4·f·(1?m))<0.0004??(1-1) where ?3SA (?RMS) represents a rate of change of a third order spherical aberration of the objective lens when the temperature of an entire body of the objective lens uniformly changes, f (mm) represents the focal length of the objective lens for the light flux having wavelength ?, and m represents the magnification of the objective lens.

Abstract: An optical pickup lens device includes, in the order from the light source side, a collimating lens for converting a bundle of rays into parallel rays or predetermined convergent or divergent rays, the collimating lens being movably held along a direction of an optical axis of a bundle of rays emitted from a light source; an aberration correcting element for allowing a bundle of rays emitted from the collimating lens to be transmitted therethrough; and an objective lens element having a numerical aperture of 0.8 or more, and converging a bundle of rays coming from the aberration correcting element onto the information recording medium to form a spot. The aberration correcting element and the objective lens element are integrally held together in a direction orthogonal to the optical axis so as to perform tracking on the information recording medium, and satisfy predetermined conditions.

Abstract: An optical scanning device for scanning an information layer (104) of an optical record carrier (102) includes a radiation source (110) for generating a radiation beam (108) and a high-NA objective system (118) for converging the radiation beam on the information layer. The objective system includes a first lens (116) and a second lens (117). The first lens and the second lens are made of plastic. The signs of the temperature-dependence of the spherical aberration of the first and second lens are different and the magnitudes of the temperature-dependence of the spherical aberration of the two lenses is substantially equal such that the temperature-dependence of the spherical aberration of the objective system as a whole is reduced to less than 30 m? OPDrms for a temperature change of 30 K.

Abstract: An image pick-up lens system includes an aperture stop (10), a biconvex first lens (20), a second lens (30) having a concave surface on an object side, and a third lens (40) having a concave surface on an image side. The aperture stop (10), the first lens (20), the second lens (30) and the third lens (40) are aligned in that order from the object side to the image side. All lenses in the system are made from a plastic or resin material, and one of them has a diffraction grating formed on a surface. The system satisfies conditions (1)-(5) as disclosed, in order to provide compactness, cost-effectiveness and improved optical performance.

Abstract: A ring zonal phase correction lens made of resin is provided with a refraction face structurally formed on at least one of a first lens face and a second lens face. The refraction face includes three or more ring zonal shaped refraction curved surfaces which are formed to be adjacent to each other through step portions formed in an optical axis direction for correcting a phase of a laser beam emitted from a laser by respective ring zonal shaped refraction curved surfaces. The step portion is formed such that a lens thickness of an outer ring zonal shaped refraction curved surface becomes thicker than that of an inner ring zonal shaped refraction curved surface and the step portion is formed at a half or more outer area of an effective radius of the refraction face.

Abstract: A bi-convex solid immersion lens is disclosed, having a top and bottom convex surfaces. The radius of curvature of the bottom surface is larger than that of the top surface. A conical sloped side-wall connects the top and bottom surface.

Abstract: An objective lens module includes a light-converging lens that is coaxially disposed with respect to an optical axis of first laser light having a first wavelength, and a transmission-type diffractive optical element that is coaxially disposed to cause diffracted light of first laser light to be incident on the light-converging lens. The diffractive optical element has an incident surface and an emergent surface, and first, second, and third regions that are provided on at least of the incident surface and the emergent surface in the vicinity of the optical axis, and are sequentially defined according to different radius distances from the optical axis to have different diffraction gratings of different diffraction angles, respectively.

Abstract: A scanning module for scanning a document is provided. The scanning module comprises: a chassis; a light source on the chassis for emitting a light ray onto the document; a plurality of reflectors inside the chassis; a lens inside the chassis; an image sensing device inside the chassis, an image of the document being reflected by the plurality of reflectors and formed on the image sensing device, the image sensing device including a plurality of sensing cells; and a plurality of microlenses on the plurality of sensing cells, each of the plurality of microlenses having a top surface and a bottom surface, the top surface having a plurality of notches as an input window for changing an incident angle of the light ray, the bottom surface having a plurality of round curves as an output window for further focusing the light ray.

Abstract: An optical pickup lens device includes, in the order from the light source side, a collimating lens for converting a bundle of rays into parallel rays or predetermined convergent or divergent rays, the collimating lens being movably held along a direction of an optical axis of a bundle of rays emitted from a light source; an aberration correcting element for allowing a bundle of rays emitted from the collimating lens to be transmitted therethrough; and an objective lens element having a numerical aperture of 0.8 or more, and converging a bundle of rays coming from the aberration correcting element onto the information recording medium to form a spot. The aberration correcting element and the objective lens element are integrally held together in a direction orthogonal to the optical axis so as to perform tracking on the information recording medium, and satisfy predetermined conditions.

Abstract: Optical elements are provided. An optical element is formed by injecting resin material into a mold through a gate in a first direction. The optical element includes a main body, a flange surrounding and connecting the main body, and a curved depression formed between the main body and the flange. The main body has a central axis and a first curved surface. The flange includes an annular abutting surface and a connecting portion. The connecting portion has a connecting surface connecting the first curved surface and the abutting surface. Both of the abutting surface and the connecting surface are perpendicular to the central axis.

Abstract: An optical element-for use in an optical pickup apparatus for converging a light flux onto an information recording plane of an optical information recording medium, is provided with an optical path difference providing section divided coaxially around an optical axis so as to form a plurality of ring-shaped zones; and a refracting section optimizing a spherical aberration of a converged light spot of a light flux which has the operating reference wavelength ?0 and is converged onto the information recording plane.

Abstract: An objective lens has a first meniscus-shape lens including a first object-side surface having a positive reflective power; and a second meniscus-shape lens having a positive reflective power. The first meniscus-shape lens and the second meniscus-shape are arranged in that order from an object side. The objective lens satisfies the following formulas: fF/f??1.1 LH1H2/f?0.5 fB/f?0.2 L/f?1.3 where f is an object-side focus length of the objective lens, fF is a front focus, fB is a back focus, LH1H2 is a length between an object-side principal point H1 and an image-side principal point H2, and L is a length on an optical axis of the objective lens between the first object-side surface and the second image-side surface.

Abstract: Provided is an objective optical system employing a gradient index (GRIN) lens. A refractive index of the GRIN lens is changed in an axial direction and a direction perpendicular to the axial direction. The GRIN lens has a refractive index n satisfying the following equation: n ? ( r , z ) = ? i = 0 ? ? n r2i ? r 2 ? i + ? j = 0 ? ? n zj ? z j where z is a distance from the center of the lens in the axial direction and r is a distance from the center of the lens in the direction perpendicular to the axial direction. Thus, an objective optical system with a high numerical aperture can correct aberration.

Abstract: A beam shaping apparatus including an optical lens is provided. The optical lens includes a diverging surface and a cylindrical surface. The diverging surface expands the input laser beam into a uniform line in one plane. The cylindrical surface converges the laser beam in another plane. Therefore, the output laser line has the desired width and the uniform density along its length.

Abstract: An optical system has an expander lens and an objective lens. The following formula is satisfied: W1CM>W2CM, where W1CM is a coma aberration (?rms) of a converged light spot when an off-axial light flux of a wavelength ? (nm) emitted so as to converge at a distance position from the optical axis comes into the objective lens, and W2CM is a coma aberration (?rms) of a converged spot when an off-axial light flux of the wavelength ? (nm) emitted so as to converge at the distant position distant comes through the expander lens into the objective lens on a condition that the optical axis of the expander lens is arranged so as to conform with the optical axis of the objective lens.