Battelle Memorial Institute

Canon Kabushiki Kaisha

Battelle Development Corporation

Medex, Inc.

Carl M Verber

Richard P Kenan

Van Earl Wood

Anthony A Boiarski

James R Busch

Nile F Hartman

Philip M Dunson

Richard Ridgway

Thomas B Smith

Blood gases and the like are monitored by a single probe having multiple dye wells and dyes immobilized in the wells, the dyes being exposed to the blood gases. Optical fibers and waveguides connected to the dye wells permit light to be directed from a light source to be dyes and the light due to absorption or the spontaneous emission of the dye returned to a light detector. The intensity, phase shift or other mechanism of the returned radiation is a measure of the partial pressure of a respective blood gas.

Integrated optic system for monitoring blood gases

Methods and apparatus for all-optical analog to digital conversion. An analog optical input signal is directed along a path comprising a series of level sensing means for determining whether its intensity is above or below a threshold value. The optical signals from successive level sensing means are directed in pairs to optical exclusive-or gates to provide a digital optical signal to at least one of a plurality of individual optical output means according to a designated digital coding system whereby the optical digital indication corresponds to the sensed level of intensity of the analog optical input signal. Apparatus comprising channel waveguides and integrated optical devices provide economical systems for high-speed computation and other uses.

All-optical A/D conversion using integrated nonlinear guided wave

Apparatus (FIG. 1) receives electrical input potentials (11A-11D) representing components, e.g. coefficients (zero or one), of weighted digital input data, and provides analog optical output (12) proportional to the sum of the weighted digital values in the input data. An electrooptic waveguide (13) has four adjacent electrooptic diffractive means (14A-14D), each responsive to a separate component of the digital input data and comprising a first electrode (15A-15D) and a second electrode (16A-16D) on the waveguide (13) for temporarily changing the index of refraction when different electrical potentials are present thereon, and thus forming a Bragg grating therein with a direction of Bragg incidence in the same input direction (17) and a direction of Bragg diffraction in the same output direction (18). A coupling prism (21) directs light from a laser (20) to enter into each diffractive means (14A-14D) in the input direction (17). Binary digital circuitry (24) provides, via voltage dividers (25A- 25D), an electrical potential (at 27A-27D, 26) to each electrode (15A, etc., 16A, etc) in each diffractive means (14A, etc), such that the difference between the potentials at the electrodes (15A, 16A, etc) for each diffractive means (14A, etc) responsive to a component of the data (24) having the value of one forms a Bragg grating that diffracts in the output direction (18) a portion (Io8, Io/4, Io/2, Io) of the input light (22) having an intensity proportional to the weighted value (2.sup.-3, 2.sup.-2, 2.sup.-1, 2.sup.0) of that component of the digital input data (24).

D/A conversion apparatus including electrooptical multipliers

Method and apparatus provide a series of optical analog intensities that are approximately proportional respectively to the components of a third array that is the product of a first array of components multiplied by a second array of components in a predetermined order. A laser (127) and collimating lens (128) (FIG. 5) direct input light (111) to a first set of electrooptic modulator (118) each of whose output light intensity varies with an electrical signal applied to it serially by electronic circuitry (129) (FIG. 12) for each respective component of the first array. A waveguide (130) directs output light from each first modulator (118) to a respective second electrooptic modulator (123), similar to the first, and similarly controlled by electronic circuitry (131) for the second array. The intensity of the output light from each second modulator (123) is responsive to the product of its two respective components. An imaging lens (132) directs the output light (115) from each second modulator (123) to a respective detector in the set ( 133), providing an electrical signal responsive to the product of its two components.

Optical engagement array multiplication

Apparatus receives light (11) in an input direction (12) and controls the directions in which portions of it travel through adjacent regions (13,14,15,16) in a waveguide (19) to emerge (at 17) in an output direction (18) with intensity responsive to a plurality of electrical potential differences (A1-A2, etc.). A plurality of electrooptic reflective means (20), each comprising a pair of electrodes (21,22, etc.), with each reflective means (20A,20B,20C,20D) on a different region (13,14,15,16), form a separate Bragg grating in each region with a direction of Bragg incidence in the input direction (12). A prism (29) directs light (11) from a laser (30) to enter in the input direction (12) into each electrooptic means (20). A plurality of control means (A,B,C,D), one for each region, each comprising means for applying a first electrical potential (A1,B1,C1, or D1) to the first electrode (21,23,25, or 27) and means for applying a second electrical potential (A2,B2,C2, or D2) to the second electrode (22,24,26, or 28) of the electrooptic reflective means (20A,20B,20C, or 20D) in the individual region (13,14,15, or 16), further direct a portion of the light (11) entering into the individual region (13, etc.) by providing a Bragg reflection thereof beyond the region (as at 17) in the output direction (18) to output means (32,33), which receive the light (17) and respond to it.

Electrooptical comparators

Methods and apparatus for providing an optical analog quantity proportional to ##EQU1## Input light (a.sub.4) of intensity proportional to a.sub.n is directed (21,31) to the input end of an nth optical module comprising a modulator (22) whose output light intensity is responsive to an electrical potential difference across it and a beam combiner (23). While the light is passing through the modulator (22), a potential difference (24) is applied across it such that the intensity of the output light from the modulator (22) is proportional to a.sub.n x, and this light (a.sub.4 x) is directed, through the beam combiner (23), to the output end of the optical module. Input light (a.sub.3) of intensity proportional to a.sub.n-1 is directed (25), via the beam combiner (23), to the output end of the optical module, to combine with the light from the modulator (22) so that the intensity of the output light (32) from the nth optical module is proportional to a.sub.n x+a.sub.n-1 ; this light is directed to the input end of an (n-1)th optical module essentially similar to the nth; and so on in the same manner; and finally to the first module, so that its output light has an intensity proportional to p(x).

Apparatus for evaluating a polynomial function using an array of optical

A Luneburg lens formed on an optical waveguide has a protective coating to assure stable optical characteristics by preventing changes in the focal length due to exposure to surrounding light and/or moisture. The Luneburg lens may be of As.sub.2 S.sub.3 material provided on a Ti in-diffused LiNbO.sub.3 waveguide.

Protected Luneburg lens

Apparatus for receiving light entering therein and controlling the directions in which portions of the light travel therethrough. Input means (21) directs portions (22) of the entering light (20) in a predetermined input direction (23) into a processing region (24) in a waveguide (25). Control means (26) temporarily and separately changes the index of refraction in each of a plurality of subregions (27) in the processing region (24), to modulate the light (22) travelling thereto in approximately the predetermined input direction (23) differently from any light travelling thereto in other input directions. Output means (28) receives portions (29) of the light travelling beyond the subregions (27) in at least one selected output direction (30) and responds thereto. Typically each subregion (27A-27H) is such that providing altered indexes of refraction therein can form in the subregion (27A-27H) a Bragg grating positioned with a direction of Bragg incidence approximately in the predetermined input direction (23). The control means ( 26) typically comprises an electrooptic grating (27A-27H) (having a plurality of interdigital electrodes (32)) in each subregion (27), and means (26A-26H) for applying a potential difference to each grating (27A-27H) separately, and thus providing an electrical field in each subregion (27) at selected times. The apparatus (FIG. 1) is especially useful and advantageous in character generators (FIG. 3), correlators (FIGS. 4,5,9,10), and the like.

Apparatus for controlling light in electrooptic waveguides with

Apparatus (FIG. 2) receives light (11) in an input direction (12) and controls the directions in which portions of it travel through regions (13,14) to emerge (at 15) in an output direction (16) with intensity responsive to the product of two electrical potential differences multiplied together. Electrooptic reflective means (18) comprising two electrodes (19,20), on a region (13) in a waveguide (17), form a first Bragg grating (18) with a direction of Bragg incidence in the input direction (12). Similar means (23) comprising two electrodes (24,25), on a region (14), form a second Bragg grating (23) with a direction of Bragg incidence the same as a direction of Bragg reflection (22) from the first grating. A prism (26) directs light (11) from a laser (27) to enter in the input direction (12) into the electrooptic means (18). Control means (28) apply a potential difference (A) to the electrodes (19,20), to further direct light (11) in the region (13) by providing a first Bragg reflection thereof into the region (14). Control means (30) apply a potential difference (B) to the electrodes (24,25), to further direct light (11) by providing a second Bragg reflection thereof in the output direction (16) to output means (35,33) (FIG. 3), which receive the twice-reflected light and respond thereto. Apparatus as in FIGS. 3 and 5 can perform multiplication of vectors, and of a matrix by a vector.

Electrooptical multipliers

A very compact light beam scanning system is provided by utilizing the optical integrated circuit technique. A Luneburg lens of As.sub.2 S.sub.3 and a SAW transducer device are provided on a waveguide and a wideband heterodyning RF oscillator including two varactor tuned oscillators and a digital linearization circuit are provided as the drive circuit for the transducer device.

Light beam scanning system with saw transducer

A method for forming a Luneburg lens having a predetermined focal length on an optical waveguide includes fabricating the lens on a waveguide from a photorefractive material and then exposing the lens to energy radiation, particularly ultra violet light, to thereby adjust the refractive index until the predetermined focal length is established.

Method of adjusting a Luneburg lens

Apparatus for comparing first and second sets of voltages having one-to-one correspondence, and providing an indication responsive to the magnitudes of the pairwise differences of the voltages; typically comprising a plurality of channel waveguides (11), each having a first electrode (12) on one side of the channel (11) and a second electrode (13) on the opposite side of the channel (11); contacts (14) and conductors (16) for connecting each voltage of the first set to the first electrode (12) of one waveguide (11); contacts (b 15) and conductors (17) for connecting each voltage of the second set to the second electrode (13) of the waveguide (11) to the first electrode (12) of which the corresponding voltage of the first set is connected; a coupling prism (18), a beam splitter (19), and a waveguide portion (20) for directing to the input end (21,22) of each waveguide (11) a substantially plane wave of coherent light (as indicated at 23,24,25) having predetermined relative intensity and phase; and a detector (51) and associated circuitry (52,58) responsive to the light emerging (as indicated at 26) from the output end (28,29) of the waveguides (11) (via a beam splitter 44 and a coupling prism 45) for providing an indication that is a function of the pairwise relative magnitudes of the first set of voltages and the second set of voltages.

Pairwise comparison device

Methods and apparatus for directing a beam of optical radiation toward a selected location and modulating the intensity thereof at the location by directing the beam over a path that includes a Bragg grating, and selectively modifying the angle between the direction at which the beam enters the Bragg grating and a direction of Bragg incidence of the grating by applying an electric or acoustic field to change the index of refraction in a portion of the path. An electric field may be applied either by interdigital electrodes at the grating, to change the Bragg angle thereof, or by electrodes at different angles across an earlier portion of the path, to change the direction at which the beam enters the grating. An acoustic field may be applied in an analogous manner. Useful for modulating and switching in planar wave guides and bulk material.

Growing community of inventors

Columbus, OH, United States of America

Carl M Verber