Colonel John Battelle was an early Ohio industrialist with major interests in the iron and steel industry and subsidiary interest in other metals. His son, Gordon Battelle, developed a consuming interest in industrial research mainly as a result of trying to recover zinc from ores for which the usual roasting process did not work. When Gordon Battelle died in 1923, he left his residual estate to the founding of an institute ". . . for the purpose of education in connection with the encouragement of creative and research work and the making of discoveries and inventions . . ." When his mother, Annie Norton Battelle, died in 1925, she left the bulk of her estate to the institute her son had founded. Battelle Memorial Institute opened its doors for business in 1929.
We describe a portable astronomical polarimeter system employing a photoelastic modulator and digital synchronous detection to extract simultaneously three of the four Stokes' parameters of the incident light. Light polarization by the telescope optics is the major systematic offset error. A mini-computer is employed for data handling, control, and quick-look Fourier transformation of time-series data.
Thick phase gratings have a variety of possible uses as device components in integrated optical systems. The applications make use of one or more of the unique properties of these gratings: high diffraction efficiency, good angular selectivity, and straightforward fabrication. In planar waveguides, the diffraction efficiency and angular selectivity desired for a particular application determine the length of the grating along the waveguide surface. We have holographically recorded 2 mm gratings having peak diffraction efficiencies in excess of 50% and angular selectivities less than 2 mrad by intersecting guided waves in a sample of photorefractive LiNbO3. Such gratings provide the central element in a number of actual and contemplated waveguide devices, including mirrors, beam splitters, lenses, switches, modulators, and interferometers.
A CO2 TEA laser was built which is excited by a single short discharge pulse without using any preionizing devices. The laser is tunable to more than 80 lines between 9.1 IJIM and 10.9 pm. Maximum output energies of 20 .11 and peak powers in excess of 100 MW were obtained. Laser radiation was also generated using N20, CO and HF.
An optical information storage system based on direct binary bit imaging is described. The recorded bit diameters are about one micron, and a density of about 5 x 107 bits/cm2 has been demonstrated. Color television program material has been encoded in a differential PCM format, recorded and played back in real time. The system uses a stationary rec-ord, and a scanned optical aperture that is smaller than usual for these bit densities. The present work has been directed toward a low cost video player/recorder for home use. Optical digital recording is a technique for high density storage of binary information. Each information bit is stored as a discrete, direct image in contrast to the more usual holo graphic transform images. By the use of short focal length lenses and a mechanical scanner a data density of 5 x 1 07 bits per square centimeter and data rates of 3 x 107 bits per second have been demonstrated. For comparison, the information on a typical reel of computer tape (2600 ft at 1600 BPI) could be stored in roughly one square inch on this optical record. This technology was developed for several applications. The first, consumer prerecorded TV, is reported here. This choice was made because a video record would require the highest densities and the simplest, lowest cost player of all the applications considered. In effect, the results of this work would help define those applications that are commercially feasible. Color TV material has been successfully re corded in real time and played back with basically no degredation of the signal. The luminance bandwidth is 3.5 MHz plus the .6 MHz color components. The playback device is simple and probably inexpensive in quantity. Holographic data storage techniques were not used for this work because the inherent advantages of holographic systems can be had with properly designed direct bit systems, while the playback equipment for direct systems appears less expensive. Scanner In contrast to much previous work, the record element is held stationary during re
This paper describes the development of a holographic instrument designed to take the place of the test glass in testing lens surfaces. The objective was to produce an instrument giving similar results as the test glass, while preserving its simplicity. The research performed in this project resulted in a very simple system wherein a single hologram contains a complete interferometer supplying both the illumination source and the reference. The instrument is designed to be used on lens surfaces without the need to remove them from the mandrel of the polishing machine. It is simply placed on the optical surface, contacting it at three points. Fringes similar to those obtained with a test glass are seen on a screen on the instrument. Each lens design requires a hologram specifically made to test its particular curvature. Since the holograms can be made cheaply and rapidly, considerable cost savings should result, since no precision test glasses need be made.
An automated diagnostic system has been developed and installed on a multibeam laser for fusion research. Laser-beam phase and intensity profile, focal-spot profile, pulse width, beam energy, and other laser parameters are measured at a number of points in the system. Data from the optical and voltage sensing elements are processed by an on-line mini-computer and the information is presented in graphic, pictorial, and tabular form. The processed information is used
The development, construction and space qualification of an IR modulator for f/1 radiation in the 14-16 pm band is described. The modulation is based on the principle of a vibrating Fabry-Perot (FP) interferometer with gap width variations of -Â±Am/8c,-, 2 pm (A-center wavelength) which is considered micromechanical. By connecting two such Fabry-Perot interferometers in series (with two outer CdTe plates in fixed positions and one common vibrating inner CdTe plate for harmonic gap width variation) a modulation effici-ency of about 75% is attained. CdTe is superior to other materials as far as IR absorption (0.2%/cm) within the -20Â°C to +60Â°C temperature range and the 2 to 25 11M wavelength range is concerned. Its modulation efficiency in a single FP interferometer is however too low because of its low refractive index (n = 2.5). The double FP interferometer is designed for small weight, large receiving aperture, small power consumption and high reliability in long-time space operation. The modulator is operated at a selected resonance frequency between 100 Hz and 1 kHz. It can be tuned to other wavelengths in the 2 to 25 pm range.
A method of determining internal temperatures within a semitransparent nonscattering slab is discussed. The appropriate equations and boundary conditions are reviewed and are valid for both arbitrary angles and the effects of polarization. A numerical procedure for recovering the internal temperature profile from experimentally determined, externally observable intensities is presented and shown to be both accurate and efficient. Two illustrative examples indicate the possible effects of inaccurate intensity data and how the use of polarization and various viewing angles can be useful.
A high-speed profile monitor has been developed for Frank-ford Arsenal as an integral part of an automatic 5.56 mm cartridge case ammunition inspection system. This profile gaging monitor uses a dual measurement station each with solid state linear diode arrays and shadow-imaging optics to achieve a throughput rate that exceeds 1200 cases/minute with a diameter measurement standard deviation better than ± 1.5 x 10-3 inch. Fourteen diameters and two lengths are measured on each cartridge case by separate gaging stations. Length measurements use a snapshot-type optical system while diameter measurements require both image tracking of the case shadow and scanning operation to get the diameter measurements from two diode array elements. A mini-computer with a direct memory input from the gaging stations provides an engineering unit conversion from the gaging stations and a dynamic accept/reject decision based on minimum accept and maximum accept limits.
An optical surface flaw inspection monitor has been developed as a part of Frankford Arsenal's Cartridge Case Measurement Eject System for 5.56 mm small-caliber ammunition. This surface flaw monitor uses scattered light electro-optical instrumentation to detect flaw presence on 100% of the cartridge case surface at case throughput rates exceeding 1200 cases/minute. A line source formed from a laser source with cylindrical optics automatically tracks a spinning cartridge on the perimeter of a wheel-type mechanical handling system. Individual fiber optic elements located at each case position direct scattered light from surface zones of the case to common photomultiplier-based optical detectors. The detected signals are corrected for illumination and receiving optics transmissions and then frequency-processed. The frequency pattern of the detected scattered light relates directly to the type of surface flaw, such as dents and scratches. Go/no-go signals are fed directly to a minicomputer for implementation of a reject function on the mechanical handling hardware.
Fresnel reflection of most of the light from auto headlights by rain water causes highway stripes to disappear and produces a strong glare against the dark road surface on rainy nights. Battelle has developed and demonstrated the feasibility of a low-profile highway striping design that has survived snowplowing and has remained effective as a wet-night lane divider on a high-speed, high-density traffic thruway.
This paper describes an electro-optic displacement measurement system which measures both angular and lateral displacements simultaneously. The system consists of a CW laser, lenses, interference filters, beam splitter, and a position-sensing photodiode. The use of the described system has been checked and verified by use in an actual system. The system was used to measure flexure of a ship in a variety of different sea states and the results of these measurements are discussed along with the design criteria.
Raster in scanned imagery can be suppressed to improve visual observation of image detail. In the work reported here this is accomplished by optimal choice of the scanning spot and/or by optimal smoothing. Both techniques are based on selection of a Wiener filter. The optimal spot is shown to extend only over two scan lines, for scenes with 1 /f2 power spectra. The filter is designed to be used in an incoherent imaging system. It is constrained to a phase-only approximation of the optimum complex filter to avoid reducing light level in the optical system. Experimental results demonstrate the effectiveness of the filter design.
The curvature of a nearly plane wavefront can be detected in a shearing interferometer, in which one portion of the amplitude of a wavefront is made to interfere with another portion that has been shifted transversely, or sheared. When used with laser light having a high degree of spatial and temporal coherence, a shearing interferometer may consist of simply an optical-flat held at an angle to the illuminating wavefront so that reflections from the front and back surfaces interfere, as in Fig. 1. This provides an extremely simple tool for checking the adjustment and quality of laser beam expanders. The technique is of sufficient practical value to warrant a description of the simple theory and application.
Some of us learn optics or other facets of science more readily by manipulating devices and observing the results. Others are more prone to formulate an experiment abstractly and to predict results through mathematical variations, of the parameters. In other words, some of us. are experimentalists and others are theoreticians. I believe that optical education should not stress one of these approaches to the exclusion of the other. Undoubtedly, I will receive no strong opposition to that remark.