scispace - formally typeset
Search or ask a question

Showing papers on "Beam splitter published in 1995"


Journal ArticleDOI
TL;DR: In this paper, a new free-space micro-optical bench (FSMOB) technology was proposed to reduce the size, weight, and cost of most optical systems, and could have a significant impact on optical switching, optical sensing and optical data storage systems as well as on the packaging of optoelectronic components.
Abstract: The surface-micromachining technique has been employed to fabricate novel three-dimensional micro-optical elements for free-space integrated optics. The optical axes of these optical elements are parallel to the substrate, which enables the entire free-space optical system to be integrated on a single substrate. Microscale Fresnel lenses, mirrors, beam splitters, gratings, and precision optical mounts have been successfully fabricated and characterized. In addition, micropositioners such as rotary stages and linear translational stages are monolithically integrated with the optical components using the same surface-micromachining process to provide on-chip optical alignment or optomechanical switching. Self-aligned hybrid integration with semiconductor edge-emitting lasers and vertical cavity surface-emitting lasers are also demonstrated for the first time. This new free-space micro-optical bench (FSMOB) technology could significantly reduce the size, weight, and cost of most optical systems, and could have a significant impact on optical switching, optical sensing and optical data-storage systems as well as on the packaging of optoelectronic components.

127 citations


Patent
06 Nov 1995
TL;DR: In this paper, an enlarging optical system having an objective lens and an ocular lens is received in a body of a microscope, and an image obtained by an endoscope is displayed in this monitor television.
Abstract: An enlarging optical system having an objective lens and an ocular lens is received in a body of a microscope. A beam splitter is received in the body on an optical path of the enlarging optical system. This beam splitter is disposed between the objective lens and the ocular lens. A monitor television is also received in the body. An image obtained by an endoscope is displayed in this monitor television. The image displayed in the monitor television is reflected by the beam splitter toward the ocular lens.

122 citations


Patent
04 Dec 1995
TL;DR: A simplified two-light valve configuration for high performance projection displays which eliminates much complexity and the costs associated with three light valve projection displays, such as a crossed dichroic beam splitter cube, a long retrofocus projections lens, and the additional cost and complexity of a third light valve was proposed in this paper.
Abstract: A simplified two-light valve configuration for high performance projection displays which eliminates much complexity and the costs associated with three-light valve projection displays, such as a crossed dichroic beam splitter cube, a long retrofocus projections lens, and the additional cost and complexity of a third light valve. Two reflective liquid crystal light valves are positioned and aligned relative to each other on two adjacent surfaces of a polarizing beam splitter cube. Illumination is introduced through a third face of the cube, and a projection lens images the two light valves through a fourth surface of the polarizing beam splitter cube. Color-sequential and alternating polarization states are provided by a color filter wheel or cage containing individual facets of dichroic or color glass filters, such that as the wheel or cage rotates, the filters change and produce sequential red, green and blue outputs. In addition, the polarization of adjacent colors is alternated by adding a polarizing film onto each color filter.

109 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the environmental and mechanical reliability of a planar lightwave circuit (PLC)-type optical splitter modules with reference to the Bellcore requirements and concluded that the PLC splitters offer long-term stability and that their optical characteristics have sufficient mechanical strength.
Abstract: The environmental and mechanical reliability of a planar lightwave circuit (PLC)-type optical splitter modules is investigated with reference to the Bellcore requirements. The module is composed of Y-branching silica-based waveguides on Si connected to optical fiber with UV-curable adhesives and is packaged in a metal case which is filled with humidity-resistant resin. High optical performance such as low loss, low reflection, and thermal stability are obtained through the use of this fiber connection technique. Ten reliability tests including long-term environmental and mechanical tests were carried out for more than ten PLC splitter modules. Under one of the most severe sets of conditions (75/spl deg/C and 90% RH), all the 19 samples we tested were stable for more than 5000 hours. Other tests confirmed that the PLC splitters offer long-term stability and that their optical characteristics have sufficient mechanical strength. These results indicate that the PLC splitters can be used for practical applications. >

91 citations


Patent
11 Jan 1995
TL;DR: A dynamic diffractive optical transform is proposed in this paper, where an electric field pattern is created across a body of material, the material being characterized in that it has an optical transmission property which varies in response to of an electric potential applied across a portion thereof.
Abstract: A dynamic diffractive optical transform. An electric field pattern is created across a body of material, the material being characterized in that it has an optical transmission property which varies in response to of an electric potential applied across a portion thereof. The electric field pattern is created such that the resulting profile of the transmission property is an arbitrary shape which produces a desired diffraction pattern that may not be physically realizable in conventional refractive optics or is a Fresnel lens-like construct derived from a refractive optical element. This is done by selectively applying electric potentials to transparent electrode pairs having liquid crystal material therebetween and preferably relatively small proportions in relation to the relevant wavelength of light, so as to create variations in phase delay that are aperiodic, have other than fifty percent spatial duty factor or have multiple levels of phase delay. The transform is embodied in an optical scanner, an adaptive lens, and an optical switch.

89 citations


Journal ArticleDOI
TL;DR: In this article, the authors solved the problem of the transmission of time modulated signals in a two-beam coupling photorefractive set-up using an absorbing material and obtained an analytical expression that describes this phenomenon in absence of pump beam depletion due to beam coupling.

84 citations


Patent
Oomura Yasuhiro1
12 Dec 1995
TL;DR: In this article, a catadioptric optical system was proposed in which a large numerical aperture is attained on the image side and, while securing a sufficient working distance, the size of the beam splitter is reduced, thereby attaining a resolution of a quarter micron unit.
Abstract: This invention relates to a catadioptric optical system in which, a large numerical aperture is attained on the image side and, while securing a sufficient working distance, the size of the beam splitter is reduced, thereby attaining a resolution of a quarter micron unit, and an exposure apparatus using the same. In order to form a reduced image of a pattern of a first surface on a second surface, this catadioptric optical system comprises, at least, a first lens group, a beam splitter, a concave mirror having an enlarging magnification, and a second lens group. These constitutional elements of the catadioptric optical system are disposed such that light from the first surface passes through the first lens group, the beam splitter, the concave mirror, the beam splitter, and the second lens group in this order. In particular, the rear-side principal plane of the second lens group is on the second surface side with respect to a light-entering surface of the second lens group on which the light having passed through the beam splitter is incident. In addition, the concave mirror functions to collimate the light having passed through the beam splitter and then make thus collimated light re-enter the beam splitter.

82 citations


Patent
16 Sep 1995
TL;DR: In this article, a beam splitter for splitting the beam into a sample beam and reference beam was used to measure the speed of retinal blood vessels in biological samples, for example, in retinal vessels.
Abstract: Apparatus for measuring the speed of blood in blood vessels in biological samples, for example, in retinal blood vessels, which apparatus includes: (a) a source of a beam of radiation having a principal wavelength, which radiation is substantially spatially coherent and has a temporal coherence length which is less than 1 picosecond; (b) a beam splitter for splitting the beam into a sample beam and reference beam; (c) optical apparatus for directing the sample beam to an area within the biological sample; (d) a reflector for reflecting the reference beam; (e) a detector for detecting an interference between the sample beam reflected from the area and the reflected reference beam and for generating an interference signal; (f) apparatus for altering an optical path length of the reference beam from the beam splitter to the detector at an alteration velocity; and (g) an analyzer for analyzing the interference signal to determine the speed of the blood in the area from a shift of a central frequency of a frequency spectrum of the interference signal from a frequency determined from the alteration velocity and the principal wavelength.

77 citations


Patent
30 May 1995
TL;DR: In this article, a narrow-band laser apparatus comprises an optical resonator including first and second reflectors for reflecting radiation, a laser medium for amplifying radiation in said resonator and an etalon for selecting a given wavelength component from said radiation.
Abstract: A narrow-band laser apparatus comprises an optical resonator including first and second reflectors for reflecting radiation, a laser medium for amplifying radiation in said resonator and an etalon for selecting a given wavelength component from said radiation. A polarizing beam splitter is provided for linearly polarizing said radiation and also for acting as an output coupler. In order to obtain very narrow bandwidth radiation of high intensity, a Faraday rotator is provided for rotating the plane of polarization while maintaining the linear polarization thereby allowing a second wavelength selection element (such as a grating) to be efficiently employed to further narrow the output of the laser.

75 citations


Patent
07 Jun 1995
TL;DR: A phase shift illuminator (700) is comprised of a light source (704) and a phase modulator (716), typically a flexure beam micromirror array, which transversely modulates the incident light beam.
Abstract: A phase shift illuminator (700) is comprised of a light source (704) and a phase modulator (716), typically a flexure beam micromirror array, which transversely modulates the incident light beam. When a flexure beam micromirror array is used as the phase modulator (716) a polarizing beam splitter (712) and a quarter-wave plate (714) are used to separate the incident and reflected light beams. The phase modulated light beam (720) from the optical illuminator may be used in optical lithography by passing the light beam through a lithography mask (724), typically after the light beam is phase modulated, and focusing the light beam onto a target wafer (726).

72 citations


Patent
07 Jun 1995
TL;DR: In this article, an optical system for a head mounted display for a virtual reality system that employs a single high-resolution display to generate separate right-eye and left-eye images for presentation to a user is described.
Abstract: An optical system for a Head Mounted Display for a virtual reality system that employs a single high-resolution display to generate separate right-eye and left-eye images for presentation to a user. The display projects a single image onto an array of adjacent lenses that serve to magnify it, and to project the image onto an optically distant diffuser screen. The diffuser screen, which increases the angular dispersion of the image, is in close proximity to a columnar array of microprisms. The microprism beam splitter serves to split the single image into separate right-eye and left-eye component images, and to direct each component image to its respective eyepiece at an off-axis angle. The optical system further includes two separate eyepieces, each including Fresnel lens/prisms that redeflect their respective images onto optical axes which are parallel to, but laterally displaced from the original, central optical axis. Color correction is achieved by the use of a single diffraction grating that corrects the lateral color dispersion introduced by the deflecting Fresnel lens/prisms. A toroidal lens directly in front of each eye, but slightly displaced horizontally from the eye's optical axis, serves to equalize the angular magnification in the x- and y-directions, while symmetrizing the y-axis astigmatism about the center of the eye.

Patent
Hideo Yokota1
28 Sep 1995
TL;DR: The polarizing beam splitter of this invention comprises a transparent flat plate and films of a dielectric material provided on the opposite surfaces of the plate as discussed by the authors, which relates to a polarizing beacon splitter and an illuminating device having the polarizingbeam splitter.
Abstract: This invention relates to a polarizing beam splitter and an illuminating device having the polarizing beam splitter. The polarizing beam splitter of this invention comprises a transparent flat plate and films of a dielectric material provided on the opposite surfaces of the plate.

Patent
Tomowaki Takahashi1
27 Apr 1995
TL;DR: In this article, the authors used a beam splitting optical system to set a longer optical path between a concave, reflective mirror and an image plane, in which a light beam from an object surface travels through a first converging group to enter a beam splitter, and a lightbeam reflected by the beam splitters is reflected by an image of patterns on the object surface inside the concave reflective mirror.
Abstract: To use a beam splitting optical system smaller than the conventional beam splitters and to set a longer optical path between a concave, reflective mirror and an image plane. A light beam from an object surface travels through a first converging group to enter a beam splitter, and a light beam reflected by the beam splitter is reflected by a concave, reflective mirror to form an image of patterns on the object surface inside the concave, reflective mirror. A light beam from the image of the patterns passes through the beam splitter and thereafter forms an image of the patterns through a third converging group on an image plane.

Patent
29 Jun 1995
TL;DR: In this paper, a passively aligned optical interconnect is described for use as a wavelenth division multiplexer (WDM) and demultiplexer, which makes use of silicon waferboard for a low cost interconnect.
Abstract: A passively aligned optical interconnect is described for use as a wavelenth division multiplexer (WDM) and demultiplexer. The device makes use of silicon waferboard for a low cost interconnect. Computer generated holograms are used to effect the multiplexing/demultiplexing as well as focusing of the beams. In an alternative embodiment, the device is used as a beam splitter for monochromatic light. In yet another embodiment, the device is used to spatially separate the polarization states of light.

Journal ArticleDOI
TL;DR: In this article, a unitary operator representing the action of a linear lossless passive beam splitter is presented, based on an elementary group-theoretical approach that allows us to understand this action in terms of the Stokes operators for the incident beam.
Abstract: The unitary operator representing the action of a linear lossless passive beam splitter is presented. The derivation is based on an elementary group-theoretical approach that allows us to understand this action in terms of the Stokes operators for the incident beam. This operator is used to illustrate with some examples the coupling of noise in the beam splitter.

Patent
22 Nov 1995
TL;DR: In this article, a laser beam having a predetermined plane of polarization and output from a tunable wavelength light source passes through a Faraday element and a polarizer constituting an optical attenuator and is split into a split light beam and an output light beam by a beam splitter.
Abstract: To obtain a predetermined power intensity without influencing the wavelength of output light by external APC, a laser beam having a predetermined plane of polarization and output from a tunable wavelength light source passes through a Faraday element and a polarizer constituting an optical attenuator and is split into a split light beam and an output light beam by a beam splitter. The split light beam is received by a light-receiving device, and a detection signal according to the power intensity is output from the light-receiving device. A controller supplies a signal according to the difference between the detection signal output from the light-receiving device and a set value set at an intensity setting device to a coil of the Faraday element constituting the optical attenuator. The plane of polarization of the laser beam output from the Faraday element is rotated with respect to the plane of polarization of the polarizer, thereby controlling the attenuation amount of the optical attenuator such that the detection signal output from the light-receiving device always equals the set value.

Patent
26 Sep 1995
TL;DR: In this paper, a diffusion angle conversion hologram is provided between the light-emitting element and the first beam splitter film, and with respect to the diffusion angle, the relation between the incident beam and diffusion angle of the outgoing beam is specified.
Abstract: In an optical pickup, light, emitted from a light-emitting element, is transmitted through a first beam splitter film with polarization selectivity, and a zero-order diffraction beam and two (±) first order diffraction beams are produced. These beams are applied in a condensed manner to an optical disk through a condensing element, and the return light beam from the optical disk is fed to a photodetector through a second beam splitter film with polarization selectivity, thereby effecting the recording and reproduction of information, the tracking and the focusing. A diffusion angle conversion hologram is provided between the light-emitting element and the first beam splitter film, and with respect to the diffusion angle conversion hologram, the relation between the diffusion angle of the incident beam and the diffusion angle of the outgoing beam is specified. With this arrangement, the light to be incident on the condensing element can have an ideal spherical wave free from a wave aberration, so that an image spot on the optical disk can be condensed into a diffraction limit, and besides by correcting the phase of the beam, a RF signal with a high C/N ratio, a stable focus error signal and a stable track signal are detected.

Patent
Yukinori Shioya1
15 Feb 1995
TL;DR: In this article, the P-polarization component of a light beam emitted from a light source and its S polarization component is transmitted toward a liquid crystal display device by the second polarization separating surface.
Abstract: First polarizing beam splitters have respective first polarization separating surfaces arranged perpendicularly to each other. Each of the first polarization separating surfaces transmits the P-polarization component of a light beam emitted from a light source and reflects its S-polarization component. Each of first light beam reflecting elements reflects the S-polarization component reflected by the first polarization separating surface and a light beam directly inputted from the light source. Second polarizing beam splitters have respective second polarization separating surfaces, each of which transmits the P-polarization component of the light beam inputted from the light source and reflected by the first light beam reflecting element and reflects the S-polarization component. Each of second light beam reflecting elements reflects toward a liquid crystal display device the P-polarization component transmitted from the second polarization separating surface. Phase plates convert the S-polarization components that have been separated by the first and second polarizztion separating surfaces to P-polarization components by rotating their polarization directions by 90°.

Patent
26 Sep 1995
TL;DR: In this paper, a transmission and reception module for a bidirectional optical communication and signal transmission includes a light transmitter having a first lens coupling optical element, and a light receiver which is orthogonal to the light transmitter.
Abstract: A transmission and reception module for a bidirectional optical communication and signal transmission includes a light transmitter having a first lens coupling optical element, and a light receiver. A fiber connection has a second lens coupling optical element for a common optical waveguide. A beam splitter is disposed in a free beam path. A common housing surrounds the foregoing. The light transmitter, the beam splitter and the fiber connection as well as the light receiver which is orthogonal thereto, are disposed axially symmetrically. An optical axis of the first lens coupling optical element is axially offset from an optical axis of the light transmitter, an optical axis of the second lens coupling optical element is axially offset from the optical axis of the fiber connection, the end surface of the fiber connection, given optimal coupling-in of light, has an angle of inclination relative to its optical axis, and the beam splitter is inclined relative to an axis of symmetry of the configuration, such that backreflected radiation strikes neither a radiation-active part of the light transmitter nor a radiation-sensitive part of the light receiver.

Patent
05 Sep 1995
TL;DR: In this article, the phase difference between two orthogonally polarized components of a test beam as well as the intensities of these two components were measured using a beam block.
Abstract: A method and system for measuring the phase difference between two orthogonally polarized components of a test beam as well as the intensities of these two components. A partially-polarizing beamsplitter (101) divides a polarized test beam (103) into first and second spatially-separated beams (154,104). The first beam (154) passes through a wave plate (160) oriented so as to retard the phase of the s polarization component with respect to the p polarization component. The first beam (154) then passes through a first polarizing beamsplitter (155), to produce a first pair of spatially separated output beams (156,157) with mutually-orthogonal linear polarizations. The second beam (104) is likewise passed through a second polarizing beamsplitter (105) to produce a second pair of linearly-polarized output beams (106,107). Photodetectors (108,109,158,159) send an electrical signals proportional to the intensities of the beams (106,107,156,157) to a computer (99). The computer (99) calculates the phase difference between the s and p polarization components of the test beam, as well as the relative intensities of the s and p polarization components of the test beam. The invention also provides methods and means for calibrating the inventive apparatus using polarizing elements (52,53,54) and a beam block (51). The calibration procedure determines the phase retardance of the wave plate (155), the polarizing characteristics of the partially-polarizing beamsplitter (101), and the electrical characteristics of each of the photodetectors (108.109,158,159).

Patent
Jin Yong Kim1, Dae-Young Kim1, Man-Hyung Lee1, Song-Chan Park1, Song In-Sang1 
04 Dec 1995
TL;DR: In this article, an improved optical pick-up apparatus capable of reading data irrespective of disc type was proposed, which includes a light source, a beam splitter for passing through or splitting a beam from the light source and an objective lens for condensing the beam onto corresponding disc among discs having different thicknesses and different densities.
Abstract: An improved optical pick-up apparatus capable of reading data irrespective of disc type capable of reading various kinds of discs having different thicknesses and writing densities using only one pick-up apparatus, which includes a light source; a beam splitter for passing through or splitting a beam from the light source; an objective lens for condensing the beam onto corresponding disc among discs having different thicknesses and different densities; a numerical aperture control unit for controlling an effective numerical aperture of the objective lens so as to execute a focussing operation with respect to a certain disc; and a photo-detector for receiving the beam reflected by the disc and transmitted from the beam splitter.

Journal ArticleDOI
TL;DR: In this article, the balance between high quality optical elements and high brightness sources depends on the exact nature of the interferometer setups, which remains a big technological issue in soft x-ray interferometry.
Abstract: The development of soft x‐ray interferometry demands high quality optical elements and high brightness sources. However, the balance between these two requirements depends on the exact nature of the interferometer setups. Generally speaking, amplitude division interferometers require beam splitters, the optical quality of which remain a big technological issue. On the contrary, the high brightness sources needed by wavefront division interferometers are readily available, and will progress in the near future. Examples of such interferometers are given for various applications in development or in project.

Patent
17 Mar 1995
TL;DR: In this paper, an optical system consisting of an objective lens, a beam splitter for reflecting the first light beam and the S-polarized component of the second light beam was proposed.
Abstract: An optical head has a first light source for emitting a first light beam having a first wavelength, a second light source for emitting a second light beam having a second wavelength larger than the first wavelength, and an optical system for guiding the first and second light beams to an optical disc and guiding light beams reflected by the optical disc to an optical detector. The optical system comprises an objective lens, a beam splitter for reflecting the first light beam and the S-polarized component of the second light beam and transmitting the P-polarized component of the second light beam, and a quarter wavelength plate. When a high density medium is set against the optical hend, recording is performed by the second light beam and reproduction is performed by the first light beam. When a low density medium is set against the optical head, recording and reproduction are carried out by the second light beam. A single optical head provides read/write compatibility with optical discs of different densities, and recording and reproduction can be made on a high density optical disc.

Patent
29 Jun 1995
TL;DR: In this paper, a light beam emitted from a semiconductor laser (114) element is collimated by a collimating lens (102), and is applied to an optical disk (105) through a polarizing holographic beam splitter (181), a λ/4 plate (115), and an objective lens (103).
Abstract: A light beam emitted from a semiconductor laser (114) element is collimated by a collimating lens (102), and is applied to an optical disk (105) through a polarizing holographic beam splitter (181), a λ/4 plate (115) and an objective lens (103), a light beam reflected by the optical disk is applied to the polarizing holographic beam splitter and is diffracted Diffracted light beams of +1st order and -1st order are applied to two photodetectors (191, 192), and a focus error signal is obtained on the basis of the diffracted light beam of +1st order and a tracking error signal is obtained on the basis of the diffracted light beam of -1st order

Journal ArticleDOI
TL;DR: Polarization-selective gratings in the resonance domain of diffractive optics are calculated by use of rigorous electromagnetic diffraction theory and the profile of binary surface-relief gratings is optimized with a nonlinear Newton algorithm to design diffractive polarizing beam splitters.
Abstract: Polarization-selective gratings in the resonance domain of diffractive optics are calculated by use of rigorous electromagnetic diffraction theory. The polarizing effects are attained by special surface-relief structures, and the profile of binary surface-relief gratings is optimized with a nonlinear Newton algorithm to design diffractive polarizing beam splitters.

Patent
07 Jul 1995
TL;DR: In this paper, a wavefront sensor is used to generate focused and defocused images of an object scene that is being imaged by the imaging system from a single input optical beam impinged thereon.
Abstract: A wavefront sensor for use in a staring imaging system for generating focused and defocused images of an object scene that is being imaged by the imaging system from a single input optical beam impinged thereon. The wavefront sensor includes a beamsplitter for splitting an optical input beam into identical first and second half beam portions and for focusing the first and second half beam portions onto respective first and second focal planes. A phase plate is interposed between the beamsplitter and the second focal plane for inducing a known focus error in the second half beam portion. A photodetector is also provided and is effective to form a best focused image and a slightly out of focus image at the first and second focal planes, respectively. The focused and defocused images are combinable using phase diversity techniques to estimate wavefront aberrations present in the imaging system.

Patent
13 Mar 1995
TL;DR: In this article, an objective lens has been proposed to form a condensed light spot on the recording surfaces of optical memories varying in specifications, where the reflected light beams are made incident via the objective lens 600 and a converging lens 626 on a holographic element(HOE) 624, by which the light beam are diffracted.
Abstract: PURPOSE: To execute good reproduction with plural information recording media varying in specifications in spite of the constitution small in size and low in cost by providing an objective lens having functions to form a condensed light spot on the recording surfaces of optical memories varying in specifications. CONSTITUTION: The laser beam emitted from a laser 614 transmits a collimator lens 618 and is introduced to a beam splitter 616. The laser beam reflected by this beam splitter 616 is condensed by an objective lens 600 and the microspots are formed on the signal recording surfaces 620a, 622a of the optical disks 620, 622 having different disk thicknesses. The signal recording surfaces are formed on a transparent substrate. The light beams reflected by the optical disks 620, 622 propagate backward in the same optical paths. Namely, the reflected light beams are made incident via the objective lens 600 and a converging lens 626 on a holographic element(HOE) 624, by which the light beams are diffracted. These light beams are detected by the photodetector 628. COPYRIGHT: (C)1995,JPO

Patent
22 Jun 1995
TL;DR: In this paper, a monolithically integrated optical disk pickup head is comprised of three-dimensional collimating focusing lenses, a beam splitter and 45-degree reflectors that define an optical axis in free space using surface micromachining technology to fabricate hinged vertical optical structures.
Abstract: A monolithically integrated optical disk pickup head is comprised of three-dimensional collimating focusing lenses, a beam splitter and 45-degree reflectors that define an optical axis in free-space using surface micromachining technology to fabricate hinged vertical optical structures.

Patent
20 Jul 1995
TL;DR: In this article, a beam splitter and a mirror 40 split a light beam from a laser into two components and project them so that they converge at the focal point of lens 14.
Abstract: A remote temperature sensor, comprising an infrared detector 16 and means such as a lens 14 for focusing radiation from a heat source 60 onto the detector, has an aiming system enabling the user to position the detector at the correct distance from the heat source. A beam splitter and a mirror 40 split a light beam from a laser 61 into two components and 62 and 64 and project them so that they converge at the focal point of lens 14. When the two resulting spots of light on the heat source 60 coincide, the sensor is at the correct position. The beam splitter and a mirror 40 are movably mounted on the sensor body so that the distance at which the spots coincide can be adjusted to suit the focal lengths of different sensors. The sensor may have a trigger which both initialises the temperature measurement and activates data logging.

Patent
07 Jun 1995
TL;DR: In this article, the authors proposed an efficient and cost-effective generation of two colinear laser beams or two or more intersecting beams for the purpose of alignment as in the construction industry, taking advantage of the unequal divergence of light from a typical laser diode that produces a beam of elliptical cross section.
Abstract: Efficient and cost-effective generation of two co-linear laser beams or two or more intersecting beams, for the purpose of alignment as in the construction industry, takes advantage of the unequal divergence of light from a typical laser diode that produces a beam of elliptical cross section. Two roughly equal co-linear beams of light, or two or more intersecting beams, can be generated by reflecting the collimated elliptical beam from preferably two mirror surfaces oriented obliquely to the beam and so as to divide the elliptical beam in two. If one of the reflective surfaces is a beam splitter, three essentially intersecting beams can be generated. In preferred embodiments these three beams are at right angles to each other, particularly for use in construction layout.