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Showing papers on "Waveplate published in 1988"


Journal ArticleDOI
TL;DR: A disagreement in the literature regarding the properties of a compound zero-order waveplate is resolved by showing that with respect to temperature and wavelength it behaves like a true zero- order waveplate, but withrespect to angle of incidence it behaveslike a multiple-orderwaveplate.
Abstract: The effects of changes in temperature, wavelength, and direction of propagation (angle of incidence) on the retardance of zero-order, multiple-order, compound zero-order, and temperature-compensated waveplates are described in detail. A disagreement in the literature regarding the properties of a compound zero-order waveplate is resolved by showing that with respect to temperature and wavelength it behaves like a true zero-order waveplate, but with respect to angle of incidence it behaves like a multiple-order waveplate. A previously proposed temperature-compensated design is shown to suffer from the same directional limitations. A new design for a retarder consisting of one element of a positive uniaxial crystal and one element of a negative uniaxial crystal is proposed. The retardance of such a waveplate would be much less sensitive to the direction of propagation, but somewhat more sensitive to temperature, than a typical compound zero-order waveplate.

118 citations


Journal ArticleDOI
TL;DR: The accuracy of this measurement technique in determining the optical path difference of a quarter-wave plate is of the order of 0.1 nm, thus exceeding the accuracy of other measurement techniques.
Abstract: We propose and discuss an optical heterodyne technique to measure the phase retardation of a wave plate. The accuracy of this measurement technique in determining the optical path difference of a quarter-wave plate is of the order of 0.1 nm, thus exceeding the accuracy of other measurement techniques.

51 citations


Patent
12 Aug 1988
TL;DR: In this article, the thickness of a growing thin film is monitored by directing a beam of circularly polarized monochromatic monitoring light into the layer and detecting the portion of the monitoring light reflected from the layer.
Abstract: The thickness of growing thin film layer is monitored by directing a beam of circularly polarized monochromatic monitoring light into the layer and detecting the portion of the monitoring light reflected from the layer. The difference in phase between the s and p polarized components of the reflected light is measured and those thicknesses of the layer at which the difference in phase between the s and p components is zero are related to thicknesses which are an integral multiple of one fourth of the wavelength of the monitoring light in the layer. An apparatus for monitoring the thickness of a growing layer during the fabrication of an optical thin film includes a source of light for directing a beam of light at the growing layer and a polarizer between the source and the layer for converting the light beam to a linearly polarized beam. A quarterwave plate between the polarizer and the layer converts the linearly polarized beam to a circularly polarized beam, while a polarizing beam splitter receives the portion of the beam reflected from the layer and divides the portion into a +45° polarized component and a -45° polarized component. A first detector detects the intensity of the +45° polarized component and a second detector detects the intensity of the -45° polarized component.

30 citations



Journal ArticleDOI
TL;DR: In this article, an endless phase shifter with wide optical bandwidth was described, using a Ti:LiNbO/sub 3/ integrated-optic rotating half-wave waveplate.
Abstract: An endless phase-shifter or optical frequency shifter with wide optical bandwidth is described, using a Ti:LiNbO/sub 3/ integrated-optic rotating half-wave waveplate. Conversion efficiency and sideband suppression were 95% and >25 dB, respectively, at an operating frequency of 2 MHz.

17 citations


Journal ArticleDOI
TL;DR: A fiber-optic sensor is described in which an optical retardation plate is used to encode rotary displacement information as a notched minimum in a broadband optical signal.
Abstract: A fiber-optic sensor is described in which an optical retardation plate is used to encode rotary displacement information as a notched minimum in a broadband optical signal. As the waveplate is rotated, the optical beam experiences a variable linear retardation. The signal wavelength at which the retardation is exactly one-half wave exhibits a minimum intensity transmission. The wavelength of the intensity minimum is then a function of the rotation of the retardation plate. The theoretical prediction of the sensor’s performance is developed and compared to experimental results.

15 citations


Patent
03 Feb 1988
TL;DR: An optical amplifier for amplifying optical polarization state change effects comprises an arrangement for passing polarized light through a material a plurality of times such that changes in the polarization state of the polarized light from the respective passes of the light through the material are cumulative as discussed by the authors.
Abstract: An optical amplifier for amplifying optical polarization state change effects comprises an arrangement for passing polarized light through a material a plurality of times such that changes in the polarization state of the polarized light from the respective passes of the light through the material are cumulative. The amplifier can be used in a method for detecting optical polarization state change effects wherein polarized light which is passed through the material is detected. The material may be a liquid sample from a high performance liquid chromatography system.

15 citations


Patent
17 Feb 1988
TL;DR: In this article, an annular bundle of light is collected onto an examination surface via the half-mirror and the objective lens, and that the reflection light produced at the examination surface is caused to impinge onto the lightresponsive device via the objective lenses, the light-responsive device, and the fine aperture stop.
Abstract: In order to insure a high degree of precision of measurement with a simple structure, the apparatus for measuring reflectivity employs an objective lens, a half-mirror disposed rearwardly of the objective lens and a light source means disposed on one of the optical paths so split by the half-mirror for emitting an annular bundle of light. A fine aperture stop is disposed on the other optical path so split by the half-mirror. A light-responsive device is disposed rearwardly of the fine aperture stop, a memory is coupled to the light-responsive device and a mathematical operation device is connected to the memory. An indicating device is connected to the mathematical operation device. An annular bundle of light is collected onto an examination surface via the half-mirror and the objective lens, and that the reflection light produced at the examination surface is caused to impinge onto the light-responsive device via the objective lens, the half-mirror and the fine aperture stop. In order to eliminate harmful reflection light coming from the surface of the objective lens, and to prevent a loss of amount of light at the half-mirror, polarizers are disposed one on the light source side and the other on the light-responsive device side of the half-mirror in such a way that their polarization planes cross each other at right angles, and that a 1/4 wave plate is provided between the objective lens and the examination surface.

12 citations


Patent
15 Apr 1988
TL;DR: In this article, the authors proposed a method to enable the detection of a metal pattern in high contrast by a method wherein the wavelength of an irradiation light is polarized linearly, and only a polarized component in the direction perpendicular to the direction of polarization of the irradiation is sensed by a detector.
Abstract: PURPOSE: To enable the detection of a metal pattern in high contrast, by a method wherein the wavelength of an irradiation light is limited to a range of 350 to 750nm, the irradiation light is polarized linearly, and only a polarized component in the direction perpendicular to the direction of polarization of the irradiation light is sensed by a detector. CONSTITUTION: A substance 10 to be detected, which is prepared by forming a metal pattern 2 on a ceramic substrate 1, is irradiated obliquely from above by a light source 3 through an optical filter 4 transmitting light of 350 to 750nm and a polarizing plate 5. A polarizing plate 6, a lens 7 and an image pickup means 8 are provided above said substance 10, and the polarizing plates 5 and 6 are so provided that the directions of polarization thereof are perpendicular to each other. The irradiation light from the light source 3 is made to be of the wavelength 350 to 750nm by the filter 4 and polarized by the polarizing plate 5, and the substance 10 is irradiated by a linearly polarized light. Since the substrate 1 is constituted of minute particles, the irradiation light is reflected diffusedly and the direction of polarization of a reflected light is diffused. Since the direction of polarization of the polarizing plate 6 intersects the polarizing plate 5 perpendicularly, besides, a reflected light from the pattern 2 is intercepted and the pattern 2 is detected as black, while the substrate 1 is detected as white since a reflected light from the substrate 1 is passed. COPYRIGHT: (C)1989,JPO&Japio

7 citations


Patent
26 Aug 1988
TL;DR: In this article, a method for testing the continuity of two optical fibers (12, 14) nonsimultaneously utilizing a single optical path was proposed, where the two light beams are linearly polarized in orthogonal planes.
Abstract: An apparatus (10) and method for testing the continuity of two optical fibers (12, 14) nonsimultaneously utilizing a single optical path. Two test light beams from a dual hybrid laser (30) are collimated and directed down a single optical path time-sequentially. The two light beams are linearly polarized in orthogonal planes. A quarter wave plate (42) converts the linearly polarized light into circularly polarized light, and an optical sequencer (22) directs the circularly polarized beams to a plurality of desired optical paths, each path comprising one or two optical fibers (12, 14). A second quarter wave plate (50) converts the circularly polarized light back into linearly polarized light, and a polarizing beamsplitter (24) reflects one of the beams and transmits the other. The two beams then enter the optical fibers (12, 14), where they are reflected by dichroic mirrors (26, 28) at the opposite end of the fibers (12, 14). The reflected beams retrace the original optical paths until they are reflected by a beamsplitter (38) which directs the beams onto a photodetector (58 ). The intensity of the light pulse detected by the photodetector (58) will indicate the continuity of the fibers (12, 14). Using this invention, measurements of the continuity of the two fibers (12, 14) can be made separately, resulting in increased sensitivity over methods which measure the two fibers (12, 14) simultaneously.

6 citations


Patent
Masaharu Kaneko1
07 Jun 1988
TL;DR: In this article, an electro-optic device consisting of a dichroic dye-containing, ferroelectric liquid crystal cell (10), a reflecting plate (30), and a retardation plate (20) such as a quarter wave plate disposed therebetween, is disclosed.
Abstract: An electro-optic device is disclosed which includes a dichroic dye-containing, ferro-electric liquid crystal cell (10), a reflecting plate (30), and a retardation plate (20) such as a quarter wave plate disposed therebetween, so that an incident light (x) entering the cell (10) is transformed into a linearly polarized light whose oscillation direction may be switched by changing the polarity of the electric field applied to the cell. The light is reflected by the reflecting plate (30) after passage through the retardation plate (20) and then introduced again into the cell. The retardation plate (20) is arranged so as to permit the polarized light with one of the switched oscillation directions to pass therethrough as such but to cause the polarized light with the other oscillation direction into a circularly polarized light, whereby the device is in a bright state in the former case but is in a dark state in the latter case due to the reabsorption with the dye.

01 Sep 1988
TL;DR: In this article, a linearly polarized (LP) transmit/receive measurement system is used to characterize a variety of dielectric materials and demonstrate the feasibility of modeling clutter at microwave and millimeter wavelengths.
Abstract: : Development of two measurement techniques has made polarimetric study of dielectric materials at submillimeter wavelengths possible. The first technique, a linearly polarized(LP) transmit/receive measurement system probes polarimetric behavior of a dielectric material through observation of the material's Brewster angle. The second technique, utilizes the recently developed submillimeter quarter wave plate(QWP) to perform ellipsometric determination of the dielectric material's complex refractive index. In this paper submillimeter wavelength measurement techniques are used to polarimetrically characterize a variety of dielectric materials and demonstrate the feasibility of modeling clutter at microwave and millimeter wavelengths.

Patent
09 Dec 1988
TL;DR: In this paper, a pair of rotating plates with plural disk elements and different scanning speeds are used to execute plane scanning by a rotating system and the need for a driving system for the plane scanning is eliminated.
Abstract: PURPOSE:To simplify constitution by disposing a pair of hologram rotating plates which are provided with plural disk elements and have different scanning speeds in such a manner that grating directions are different when the disk elements face each other and executing plane scanning by a rotating system. CONSTITUTION:The laser light from a semiconductor laser 1 is circularly polarized through a collimating lens 2 by a quarter wave plate 7. This light is polarized by 1st and 2nd hologram units 4, 5 and a light spot 10 is formed on a scanning surface 6 by an f.theta lens 5. The diffraction gratings of the disk elements 14, 13 of the units 4, 3 are formed respectively in the direction perpendicular to the radius direction of the disks and in the radial direction. The number omega1 of revolutions of the 1st disk rotating plate 14 and the number omega2 of revolutions of the 2nd disk rotating plate 13 are set at omega2>omega1 and while the spot 10 is linearly scanned on the surface 6, the spot is moved successively in the direction Y so that the plane scanning is eventually executed. The need for a driving system for the plane scanning is, therefore, eliminated and the constitution is simplified.

Patent
01 Jul 1988
TL;DR: In this article, a 1/2 wave plate is used to measure the minute displacement of a horizontal plane and a vertical plane by rotating a 1 2 wave plate so that the optical axis thereof is shifted with respect to a P component.
Abstract: PURPOSE:To measure the minute displacement of a horizontal plane and a vertical plane, by rotating a 1/2 wave plate so that the optical axis thereof is shifted with respect to a P component. CONSTITUTION:A beam from a light source 1 passes through a magnifying prism 2 and is bent at the right angle by a half beam splitter 3. A 1/2 wave plate 11 is provided for giving a positional difference pi between the S component and the P component of the incident beam, and a linear polarization is converted into a linear polarization perpendicular to it. A polarization beam splitter 12 separates the S component and the P component at an angle of 90 deg. to each other. Now, when the optical axis of the 1/2 wave plate 11 is set to be parallel to the incident P component, the beam is focused on a surface 5 to be measured, by an objective lens 4. A reflected light from the surface 5 to be measured is transmitted through the half beam splitter 3. The transmitted beam is focused on a four-division detector 9 through a cylindrical lens 8 by a convex lens 7. An output of this detector is subjected to arithmetic processing to calculate displacement by an arithmetic processing unit 10. Meanwhile, the S component is reflected by the polarization beam splitter 12 and focused on a surface 13 to be measured. The minute displacement of a vertical plane can be measured in the same way.

Patent
05 Apr 1988
TL;DR: In this paper, the angular aperture of an objective lens was set at a sufficiently small angular aperture by adding and disposing a polarizing plate having an annular polarization region and a quarter-wave plate successively between a beam splitter and the objective lens.
Abstract: PURPOSE: To assure the large angular aperture of the luminous flux contributing to illumination and enable setting of an objective lens at a sufficiently small angular aperture by adding and disposing a polarizing plate having an annular polarization region and a quarter-wave plate successively between a beam splitter and the objective lens. CONSTITUTION: The polarizing plate 18 having the annular polarization region and the quarter-wave plate 19 are successively added and disposed between the beam splitter 17 and the objective lens 2. The illuminating light transmitted through the annular polarization region 18a of the plate 18 is polarized to linearly polarized light which is then polarized by the quarter-wave plate 19 to circularly polarized light. The circularly polarized light part is reversed in the rotating direction of the plane of the polarization thereof with respect to the progressing direction of the light by the reflection on the surface 5a to be irradiated. Only the incident luminous flux on the annular polarization region 18a of the plate 18 is shut off when the light passes the plate 19 again. Only the luminous flux past the central part 18b contributes to the imaging. The angular aperture 2θ of the objective lens 2 is thereby set sufficiently small and the angular aperture 2α of the illuminating light sufficiently large. COPYRIGHT: (C)1989,JPO&Japio

Patent
18 Nov 1988
TL;DR: In this paper, the authors proposed an optical element which is constituted of the poly-L-menthyl methacrylate having the optical activity, which can be used as the polarization plane rotating element by utilizing such property.
Abstract: PURPOSE: To provide the element which is optically transparent and has high performance and allows working to various shapes by constituting the element of poly-L-menthyl methacrylate having optical activity. CONSTITUTION: This optical element is constituted of the poly-L-menthyl methacrylate having the optical activity. The poly-L-menthyl methacrylate to be used as the property to generate optical rotatory power by a difference in the refractive index NR of right circularly polarized light and the refractive index NL of left circularly polarized light and can be used as the polarization plane rotating element by utilizing such property. Since this methacrylate is a polymer having a homogeneous amorphous structure, there is no particular limitation in the incident direction of the linearly polarized light and various shapes are selectable. The element which has the excellent transparency and can be worked to various shapes is obtd. in this way and the sepn. of the right circularly polarized light and the left circularly polarized light is possible. COPYRIGHT: (C)1990,JPO&Japio

Journal ArticleDOI
TL;DR: In this article, the polarization characteristics of a four-wave phase-conjugate mirror utilizing the 3S1/2/3P3/2 transition in sodium atoms and different combinations of linearly and circularly polarized external waves were investigated.
Abstract: Experimental and theoretical investigations were made of the polarization characteristics of a four-wave phase-conjugate mirror utilizing the 3S1/2–3P3/2 transition in sodium atoms and different combinations of linearly and circularly polarized external waves. A good agreement was established between the experimental results and a theory developed allowing for the optical transfer of atoms between magnetic sublevels and for a residual Doppler broadening due to the noncollinearity of the wave vectors of the interacting waves.

Journal ArticleDOI
TL;DR: In this article, an optical heterodyne technique was proposed to measure the phase retardation of a wave plate and the accuracy of this measurement technique in determining the optical path difference of a quarter wave plate is smaller than the wavelength of light source divided by 6000, exceeding the accuracies of other measurement techniques.
Abstract: This paper proposes and discusses an optical heterodyne technique to measure the phase retardation of a wave plate. The accuracy of this measurement technique in determining the optical path difference of a quarter wave plate is smaller than the wavelength of light source divided by 6000, exceeding the accuracies of other measurement techniques.