Abstract: The present invention provides optical configurations, including resonant cavity and laser configurations, and related methods providing deterministic control of the polarization characteristics and frequencies of the radiant output of multi-longitudinal mode lasers, including multi-longitudinal mode gas phase lasers. Polarization control provided by the present invention includes preselection and stabilization of the angular orientations of the polarization planes of electromagnetic radiation generated by a multi-longitudinal mode laser, including preselection and stabilization of orthogonal linear polarization states generated by a dual-longitudinal mode gas phase laser.

Abstract: A laser system. The laser system includes a first laser device configured to emit a first laser beam, a second laser device configured to emit a second laser beam, and a third laser device configured to emit a third laser beam. The laser system also includes a laser combiner configured to receive the first, second, and third laser beams and output the first, second, and third laser beams with less separation downstream of the laser combiner than upstream of the laser combiner.

Abstract: Through the use of a relatively inexpensive third mirror on a novel folded hybrid unstable resonator configuration, the optimum output coupling for a given laser design can be explored quickly and easily with a minimum of intracavity mirror alignment. No changes in either the radii of curvature of the three cavity optics or their spacing are required for this exploration. In addition to providing techniques for purposefully and systematically introducing mirror edge effects or avoiding edges effects altogether, the invention provides that output beams of different width can be advantageously explored in a relatively simple and straightforward manner. The invention provides that higher geometric magnification cavity designs may be made compatible with low diffraction output coupling in a configuration that uses only three totally reflecting optics.

Abstract: A YAG/Nd:YAG block where an Nd:YAG block ends in a peak integrated inside a YAG block. The YAG block has reflective surfaces positioned at 45° to one another. The angled reflective surfaces serve as a “mirror” within the laser cavity to effectively increase the length of the cavity by a factor greater than 2. Fused to the output end of the laser cavity are a polarizer, an active/passive Q-switch, a one quarter waveplate and an output coupler. In operation, the laser cavity is pumped either from the side or the end of the cavity. The optical components of the present invention are bonded to form one optical ‘block’. All the components are prealigned during the crystal manufacturing process to form the optical laser cavity. The width of the cavity should be selected such that nearly all of the laser diode pump output is absorbed by the cavity.

Abstract: An assembly for distributing laser energy is provided that is formed using a compact rigid housing with a sealed beam path contained therein. The assembly employs a monolithic housing with modular collimator and mirror switching components installed therein to reduce its size while maintaining a sealed beam path thereby reducing the possibility of contamination of the beam path. Other than the optics and mirror, there are no elements of the distribution device contained within the beam path. In one embodiment, the assembly distributes incoming energy from a single source to one or more outputs. In another embodiment, the assembly operates as a beam combiner to direct energy from one or more sources to a single output.

Abstract: A first optical base having a high-reflection mirror and a second optical base having a partial-reflection mirror are arranged in parallel to each other on both sides of an oscillator housing. A guide light source emits a guide light for aligning optical components in an optical path of a laser light emitted from an optical resonator and adjusting a processing point on a target object. An optical-component supporting unit includes optical components that guide the laser light in a direction perpendicular to an optical axis of the optical resonator. The guide light source is arranged on the second optical base.

Abstract: A method is given for aligning an optical package comprising a laser, a wavelength conversion device, at least one adjustable optical component, and at least one actuator. The adjustable optical component may be moved to a command position by applying a pulse width modulated signal to the actuator. The command position represents an optimized alignment of the laser and wavelength conversion device. The actual position of the adjustable may be measured by measuring an output of a position measuring circuit, which may measure the voltage amplitude of an oscillation in a resonator tank circuit during an “off” period of the pulse-width modulated signal. The resonator tank circuit may comprise a capacitive element electrically coupled to the electrically conductive coil. The pulse-width modulated signal may then be adjusted to compensate for any difference in the actual position and the command position of the adjustable optical component. Additional embodiments are disclosed and claimed.

Abstract: A laser mirror assembly is disclosed with improved pointing stability. An elongated mirror includes a concave reflecting portion. A pair of elongated planar portions extend parallel to the concave reflecting portion on either side thereof. The planar portions are stepped down from the reflecting portion. The mirror is formed from copper. A pair of stainless steel strips are connected to planar portions. The bimetallic effect between the copper mirror and the stainless steel strips operates to counteract the warping of the mirror due to differential heating effects which arise during operation. In an alternate embodiment, a pair of aluminum strips are mounted on the rear surface of the mirror.

Abstract: A laser source assembly comprises a laser diode for generating a laser beam and a focusing lens for focusing the light beam. A spacer is provided for keeping the diode and the lens at a predetermined distance, and is made of a material of low expansion coefficient. Preferably, the subassembly constituted of the diode, the spacer and the lens is housed in a case made of another material that may have a higher expansion coefficient. A resilient element is provided to continuously keep the diode and the lens abutting on the opposite ends of the spacer.

Abstract: Methods and devices for coupling the output light energy of one or more stacked laser emitter bar arrays using a beam interleaver and beam combiner to achieve high brightness and coupling efficiency. Some embodiments may include wavelength control devices and methods such as VIGs and the like.

Abstract: A laser light source device includes: a light source; an external resonator constituting a resonator structure with the light source; a wavelength conversion element disposed between the light source and the external resonator, and converting the wavelength of the light emitted from the light source; and a first spacing member maintaining a state in which at least the wavelength conversion element is separated from the external resonator by a predetermined distance.

Abstract: A first mirror (5) that can be located at a reflection position (I) at which an optical path is blocked and a laser beam (a) is reflected, and a second mirror (6) that reflects the laser beam (a) which is reflected by the first mirror (5) are disposed between the condenser lens (2) and the object to be irradiated (4). The first mirror (5) is located at the reflection position (I) so that the laser beam (a) that is transmitted through the condenser lens (2) is sequentially reflected by the first and second mirrors (5 and 6), and an intensity of the laser beam (a) that is again reflected by the first mirror (5) is made to coincide with an intensity of the laser beam (a) that is reflected from the object to be irradiated (4), and the condenser lens (2) is heated in the same manner that the processing laser beam (a) is transmitted through the condenser lens (2) and irradiated on the object to be irradiated (4).

Abstract: A laser mirror assembly is disclosed with improved pointing stability. An elongated mirror includes a concave reflecting portion. A pair of elongated planar portions extend parallel to the concave reflecting portion on either side thereof. The planar portions are stepped down from the reflecting portion. The mirror is formed from copper. A pair of stainless steel strips are connected to planar portions. The bimetallic effect between the copper mirror and the stainless steel strips operates to counteract the warping of the mirror due to differential heating effects which arise during operation. In an alternate embodiment, a pair of aluminum strips are mounted on the rear surface of the mirror.

Abstract: A portable laser head has a single-piece holder configured with a plurality of spaced-apart nests. The nests are arranged to receive at least a non-linear frequency converter, a V-shaped beam splitter and a dump collimator. Alternatively, the holder has multiple nests configured to receive an input collimator and output focusing optics unit in addition to the non-linear frequency converter, V-shaped beam splitter and dump collimator. The holder is characterized by small dimensions allowing for self-alignment of the above-referred components.

Abstract: Application of a modular coaxial package design, compatible with telecommunication passive component packaging, to microchip lasers, in particular to passively Q-switched microlasers, pumped with a fiber-coupled diode, is disclosed. The number of parts is thereby reduced while providing the adequate degrees of freedom for the active or passive alignment of the optical elements within the package.

Abstract: A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium but not the optical switch. When the primary resonator is closed by the optical switch, and pulses are not being amplified, CW radiation is generated in the secondary resonator and prevents the gain-medium from being saturated. When the optical switch is operated to cause the primary resonator to amplify pulses, generation of CW radiation in the secondary resonator ceases.

Abstract: A compact optical system is provided for delivering laser radiation with high optical efficiency and uniformity. The optical system includes, in order of the propagation of light, an expander for producing a collimated beam, a beam shaper including a flat window with a diffraction pattern on one side for transforming the collimated beam into a square top-hat output beam, a corrector for bending the square top-hat output beam back to a system axis, a scan head to scan the square top-hat output beam across the substrate, and a scan lens to image the beam at the substrate plane.

Abstract: A VCSEL waveguide grating coupler is provided such that a first and second mirror are positioned to define a resonant cavity between them. The waveguide grating coupler further includes a waveguide having a first grating formed as a part of the waveguide to couple light of a first polarization mode into the waveguide. A second grating is formed on the waveguide grating coupler and is orthogonal to the first grating. The second grating is operative to enhance the light coupled to the waveguide by creating a loss difference between light of the first polarization mode and light of a second polarization mode, so that light of the first polarization mode lases preferentially within the VCSEL.

Abstract: A laser resonator and method for forming the laser resonator are provided. The method comprises placing a housing for the laser resonator in an alignment fixture, attaching a bond plate to an optical component of the laser resonator, attaching a first end of an alignment arm to the bond plate attached to the optical component, attaching a second end of the alignment arm to the alignment fixture such that the optical component is disposed over the housing, aligning, via the alignment fixture and the alignment arm, the optical component relative to the housing, and bonding the aligned optical component to the housing. The first end of the alignment arm may removed once the aligned optical component is bonded to the housing.

Abstract: An optical package includes a semiconductor laser, an adjustable mirror and a wavelength conversion device comprising a waveguide portion. The semiconductor laser, adjustable mirror, and wavelength conversion device are oriented to form an optical pathway between an output of the semiconductor laser and an input of the wavelength conversion device. The beam of the semiconductor laser is directed along the optical pathway and onto the adjustable mirror where the beam is reflected by the adjustable mirror onto the waveguide portion of the wavelength conversion device. The adjustable mirror may also be either thermally or mechanically deformable such that, when the adjustable mirror is deformed, the path of the beam along the optical pathway is altered thereby focusing the beam on the waveguide portion of the wavelength conversion device. The adjustable mirror may be adjusted such that the beam of the semiconductor laser is positioned on the waveguide portion of the wavelength conversion device.

Abstract: A wavelength variable laser smaller in size than the conventional one can be achieved by arranging a gain chip, an etalon filter and a fifth reflective mirror on an AlN submount and longitudinally integrating the gain chip in which a 45° mirror and a lens are integrated and the etalon filter. A laser cavity has a structure in which light passes through an active layer from a first reflective mirror realized by an end surface of the gain chip, is reflected by the 45° mirror at an angle of 90° and then passes through the lens. The light having passed through the lens is converted into parallel light, passes through the etalon filter and reaches the fifth reflective mirror and is then reflected. The reflected light returns through the same optical path and reaches the first reflective mirror realized by the end surface of the gain chip.

Abstract: A communication device includes communication circuitry, a coherent light source, and a housing that at least partially surrounds the communication circuitry and the coherent light source. The housing includes a translucent portion and the coherent light source is configured so as to project light through the translucent portion of the housing.

Abstract: Pre-aligned, kinematically mounted modules including processing lasers, beam trains, and individually calibrated control beams are quickly and easily replaced on subassembly bases with minimal in situ alignment, and can maintain working-spot position to micron tolerances over ambient temperature variations of ±10° C. Subassembly bases, with features for kinematically mating to a plurality of pre-aligned laser modules and to a platform base incorporated in the laser processing tool, enable multi-module subassemblies to be quickly replaced with spare subassemblies of the same type, or swapped for subassemblies of a different type. The mating features and reversible locks are designed to mitigate thermal effects that are often a dominant cause of alignment drift in processing lasers.

Abstract: A portable laser head has a single-piece holder configured with a plurality of spaced-apart nests. The nests are arranged to receive at least a non-linear frequency converter, a V-shaped beam splitter and a dump collimator. Alternatively, the holder has multiple nests configured to receive an input collimator and output focusing optics unit in addition to the non-linear frequency converter, V-shaped beam splitter and dump collimator. The holder is characterized by small dimensions allowing for self-alignment of the above-referred components.

Abstract: A tunable laser includes dispersion optics for separating generated laser pulses into first and second wavelength pulses directed along first and second optical paths. First and second reflective mirrors are disposed in the first and second optical paths, respectively. The laser's output mirror is partially reflective and partially transmissive with respect to the first wavelength and the second wavelength in accordance with provided criteria. A first resonator length is defined between the output mirror and the first mirror, while a second resonator length is defined between the output mirror and the second mirror. The second resonator length is a function of the first resonator length.

Abstract: An optical package includes a semiconductor laser, a wavelength conversion device and a MEMS-actuated mirror oriented on a base module to form a folded optical pathway between an output of the semiconductor laser and an input of the wavelength conversion device. An optical assembly is located in a mechanical positioning device and the mechanical positioning device is disposed on the base module along the optical pathway such that the beam of the semiconductor laser passes through the optical assembly, is reflected by the MEMS-actuated mirror back through the optical assembly and into the waveguide portion of the wavelength conversion device. The MEMS-actuated mirror is operable to scan the beam of the semiconductor laser over the input of the wavelength conversion device. The optical assembly may be adjusted along the optical pathway with the mechanical positioning device to focus the beam into the waveguide portion of the wavelength conversion device.

Abstract: The invention is directed to elements used in high power laser lithographic systems operating at below 250 nm, and in particular to elements that have a coating of selected materials to extend lifetime of the elements; and to a method of preparing the extended lifetime elements. The invention is particularly directed to gratings and mirrors that are coated with silicon dioxide, aluminum oxide or fluorinated silicon dioxide. The coatings of the invention attain their extended life as a result of being deposited while being simultaneously bombarded with an energetic ion plasma.

Abstract: In an integrated gimbal and High-Powered Multiband Laser (HPMBL) for use in an infrared countermeasure apparatus in a pod mounted on an aircraft, the improvement comprises an optical bench that connects the optical path between side-by-side mounted gimbal and high power laser; and a kinematic mounting system that prevents optical bench bending.

Abstract: A hand-held laser pointer is disclosed wherein the laser beam is isolated from unwanted hand tremor motions of the laser pointer housing. A laser beam is directed toward a pair of passively inertially stabilized mirrors disposed within the housing that are biased to a neutral position by a spring and damper. Both the laser beam that exits the housing and the laser dot appearing at a target are minimally affected by laser jitter associated with hand tremor.

Abstract: In a laser array unit in which a plurality of laser beams emitted from a laser array is received by a lens array, the lens holder for fixedly bonding the lens array is formed such that the length of the surface on which the lens array is bonded in the direction orthogonal to the optical axis direction of the lens is longer than the length of the surface to be bonded to a certain other fixing member in the same direction.

Abstract: A compact mid-IR laser device utilizes an external cavity to tune the laser. The external cavity may employ a Littrow or Littman cavity arrangement. In the Littrow cavity arrangement, a filter, such as a grating, is rotated to provide wavelength gain medium selectivity. In the Littman cavity arrangement, a reflector is rotated to provide tuning. A quantum cascade laser gain medium provides mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens for both the output lens and the external cavity lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less.

Abstract: A wafer-level device fabrication process forms standing structures around emitting areas of multiple VCSELs. The standing structures can be shaped to hold ball lenses or other optical elements for respective VCSELs or can include platforms on which optical elements are formed. Ball lenses that are attached to the standing structures either during chip-level or wafer-level processes fit into the standing structures and are automatically aligned. Wafer level fabrication of optical elements can align the optical elements with accuracies associated with photolithographic processes. The optical elements can be formed using a molding or replication process, a printing method, or surface tension during a reflow of lithographically formed regions.

Abstract: A laser module includes a stem provided with a device mounting structure; a light emitting device mounted onto the stem by use of the device mounting structure a tubular cap fixed to the stem in the state of surrounding the light emitting diode and provided with an aperture through which to pass laser light emitted by the light emitting device; and a light transmitting plate fixed, by use of a bonding material, to an inside surface of the cap in the state of closing the aperture. An annular projection projecting to the inside of the cap in the optical axis direction of the laser light is provided at a peripheral edge part of the aperture of the cap, and the light transmitting plate is fixed to the inside surface of the cap inclusive of the projection by use of the bonding material.

Abstract: A multi-layered reflective mirror formed of spaced-apart plate-shaped empty space patterns formed within a substrate is disclosed. The plurality of plate-shaped empty space patterns are formed by drilling holes in the substrate and annealing the substrate to form the spaced-apart plate-shaped empty space patterns.

Abstract: To provide an optical scanning apparatus which is strong against an external stress while suppressing an increase in the number of parts, an inserting portion 6 into which a laser light source unit 1 can be inserted is provided for a frame member 5. In a state where the laser light source unit 1 has been inserted into the inserting portion 6, the laser light source unit 1 and the inserting portion 6 of the frame member 5 are interference-fitted in two positions (front edge side fitting portion 4a and front edge side contact portion 6a; root side fitting portion 4b and root side contact portion 6b) which are away from each other in an optical axial direction.

Abstract: A first alignment mark member is exposed at both of a mounting surface and a bonding surface, and thus can be seen from two directions by image sensors. While a semiconductor laser device is mounted on the mounting surface of a light source supporting substrate with reference to the first alignment mark member observed from the direction of the image sensor, the first alignment mark member can also be observed from the direction of the image sensor. With reference to the first alignment mark member observed from the latter direction, the light source supporting substrate is bonded to the slider substrate. Namely, though observed from different directions, the alignment mark member is used for a common reference for two securing operations, whereby attachment errors can be suppressed.

Abstract: An optical imaging apparatus (80) for direct engraving of flexographic plates (52) includes at least two laser sources (43), each emitting laser beams (44). A mirror or prism (45) is placed in front of each of the laser sources to alter an optical path of each of the laser beams. The laser beams cut the flexographic plate at different depths and cut out chunks (65) of the flexographic plate.

Abstract: A speckle reduction laser and a laser display apparatus having the speckle reduction laser are provided. The speckle reduction laser includes a semiconductor unit that comprises an active layer and emits laser light through a first side surface thereof by resonating light generated from the active layer, and a vibration mirror unit disposed adjacent to a second side surface of the semiconductor unit. The laser further includes a mirror, and the resonance of the laser light is generated between the first side surface of the semiconductor unit and the mirror, and a resonance mode of the laser light is changed according to the vibration of the mirror.

Abstract: A laser mirror assembly is disclosed with improved pointing stability. An elongated mirror includes a concave reflecting portion. A pair of elongated planar portions extend parallel to the concave reflecting portion on either side thereof. The planar portions are stepped down from the reflecting portion. The mirror is formed from copper. A pair of stainless steel strips are connected to planar portions. The bimetallic effect between the copper mirror and the stainless steel strips operates to counteract the warping of the mirror due to differential heating effects which arise during operation. In an alternate embodiment, a pair of aluminum strips are mounted on the rear surface of the mirror.

Abstract: Because a focal distance of a condenser lens is changed due to a change in temperature, when irradiation of a laser beam is restarted after the irradiation has stopped, it takes a long time to restore a temperature of the cooled lens to a given temperature, and the operating efficiency is deteriorated. A first mirror 5 that can be located at a reflection position I at which an optical path is blocked and a laser beam a is reflected, and a second mirror 6 that reflects the laser beam a which is reflected by the first mirror 5 are disposed between the condenser lens 2 and the object to be irradiated 4.

Abstract: A technique for reducing the vibration sensitivity of laser-stabilizing optical reference cavities is based upon an improved design and mounting method for the cavity, wherein the cavity is mounted vertically. It is suspended at one plane, around the spacer cylinder, equidistant from the mirror ends of the cavity. The suspension element is a collar of an extremely low thermal expansion coefficient material, which surrounds the spacer cylinder and contacts it uniformly. Once the collar has been properly located, it is cemented in place so that the spacer cylinder is uniformly supported and does not have to be squeezed at all. The collar also includes a number of cavities partially bored into its lower flat surface, around the axial bore. These cavities are support points, into which mounting base pins will be inserted. Hence the collar is supported at a minimum of three points.

Abstract: Because a focal distance of a condenser lens is changed due to a change in temperature, when irradiation of a laser beam is restarted after the irradiation has stopped, it takes a long time to restore a temperature of the cooled lens to a given temperature, and the operating efficiency is deteriorated. A first mirror 5 that can be located at a reflection position I at which an optical path is blocked and a laser beam a is reflected, and a second mirror 6 that reflects the laser beam a which is reflected by the first mirror 5 are disposed between the condenser lens 2 and the object to be irradiated 4.

Abstract: A unidirectional ring laser oscillator has a travelling wave unstable mode in one transverse dimension and either a waveguide or freespace Gaussian mode in the orthogonal transverse dimension for coupling to large volumes of asymmetric cross section laser gain media. This device concept is shown to have unique and innovative features such as an exchange of left for right in the intracavity radiation profile without having to employ concave optics. Also, a high insensitivity to misalignment of one of the intracavity ring optics is achieved without having to suffer any deleterious effects associated with the high intensity of radiation normally encountered at an intracavity focal plane. Unidirectional operation of the laser is achieved using both intracavity and extracavity optical techniques.

Abstract: A wavelength tunable cavity includes a first reflecting unit adapted to at least partially reflect a beam of electromagnetic radiation towards a second reflecting unit, adapted to at least partially reflect a beam of electromagnetic radiation back towards said first reflecting unit, both reflecting units providing resonance modes of said electromagnetic radiation within said cavity, wherein an optical path of said beam within said cavity is defined in length by said first and second reflecting unit, a grating arranged within said optical path of said beam reflected by said first reflecting unit, said grating adapted for tuning the wavelength of said beam, wherein said at least one second reflecting unit is rotatable about an axis by at least 360 degrees along a circle path with respect to said grating, said circle path including at least a portion arranged to intersect with said beam, which is redirected by said grating.

Abstract: A laser system may include a solid-state laser gain material (LGM) module. The system may also include a multi-pass resonator including a plurality of relay mirrors. The plurality of mirrors may be grouped at least in pairs. A first mirror of each pair of relay mirrors may be positioned to cause a laser beam from the LGM module incident on the first mirror to be reflected to the second mirror, and the second mirror may be positioned to reflect the laser beam back to the LGM module for further amplification. The multi-pass resonator may be configured to provide a high-quality laser beam in the fundamental mode.

Abstract: A system and method for reducing visible speckle in images displayed using coherent light. In an embodiment, a system for displaying images includes a light source to produce coherent light, an array of light modulators optically coupled to the light source and positioned in a light path of the light source after the light source, and a controller electronically coupled to the array of light modulators and to the light source. The light source includes a coherent light source, and a first digital micromirror device (DMD) having a first plurality of micromirrors. The first DMD is optically coupled to the coherent light source and positioned in a light path of the coherent light source after the coherent light source. The first DMD directs coherent light by moving the micromirrors of the first plurality of micromirrors through a first range of tilt angles substantially continuously.

Abstract: An apparatus as a tuning filter is provided for tuning the wavelength of a laser or a filter between extensive bandwidths, including a reflecting element, an optical system and a movable mount set up in the same optical path in order. The optical system focuses light on the reflecting element that induces dispersion effect. The reflecting element moves along an optical path as a spatial filter. The reflecting element is set up on the movable mount that moves along the optical path to push/pull the reflecting element and then to adjust the moving range of the reflecting element.

Abstract: An optical device includes a chip containing a Vertical Cavity Surface Emitting Laser (VCSEL) active region that produces a laser beam on a first axis. The VCSEL can further include a post having a central axis offset a distance from the first axis. A lens can be mounted on the post such that it bends the laser beam away from the first axis. Alternately, the chip can include multiple VCSEL active regions each of which produces a laser beam on a different axis. The chip can include a post having a central axis offset from the laser beam axes. A lens can be mounted on the post such that the lens bends the laser beams away from the central axis.

Abstract: In one embodiment, a lens structure has an object surface, an image surface, and an axicon mirror. The axicon mirror is defined by an inner diameter, an outer diameter, and a tilt angle, with the tilt angle being defined by a plane of the axicon mirror and the surface of the axicon mirror. The image surface is positioned within the inner diameter of the axicon mirror. The lens structure may be incorporated into an optical transmitter having a light source and a photodetector. The light source is positioned to transmit light toward the object surface of the lens structure, and the photodetector is positioned to receive light reflected from the axicon mirror. A method for producing lens structures with different optical attenuation properties is also disclosed.

Abstract: A laser device applied to a light source of laser scanning units (LSU) including a laser diode disposed on an accommodation hole of a flange. A collimator lens is arranged on one end of an inner tube part of a holder while the other end of the inner tube part faces the laser diode. The laser beam passes through the inner tube part of the holder and the collimator lens, then projects out. A lug extends radially from outer surface of the holder and a plurality of axial guide slots are disposed on the lug. A plurality of guide pins corresponding to the guide slots are arranged on the flange. An adhesive is located between the guide pins and the guide slots and spaced apart from the collimator lens.