Abstract: A lightguiding device, which can be an integral part of a lightguiding system, can increase the light intensity exiting from a lightguide by concentrating the transmitted light into a small portion of the lightguide's cross section. The device consists of a section of a lightguiding material which has been bent at an angle greater than 45 degrees relative to the axis of light transmission, preferably at an angle of 90 degrees with a small bend radius. In the bent section, a homogeneous refractive index is required at least for the lightguide's core. The lightguide must be terminated immediately beyond the bent section. Alternatively, a preformed bent section of appropriate lightguiding material can be attached to an end of a straight section of lightguide to increase the exiting light intensity. All types of lightguiding systems can be used to enhance output intensities, including glass or pure silica lightguides, hollow waveguides, liquid core lightguides and plastic lightguides.

Abstract: An apparatus for aligning a plurality of optical fibers in predetermined positions with respect to one another. The apparatus includes a top plate and a bottom plate having a first set of alignment groves therein, there being one such grove corresponding to each optical fiber. The alignment groves are positioned such that the optical fibers will be in their correct positions with respect to one another when the optical fibers are forced against the bottom of the groves by the top plate. To reduce reflections from cut fiber ends that would normally be cut and polished, the optical fibers are cut at an angle with respect to the axis of the optical fiber and the cut end is bonded to an optical flat by a glue layer having the same index of refraction as the optical fiber. In the preferred embodiment of the present invention, the optical flat also includes an anti-reflective material on the non-glued surface thereof.

Abstract: A method of controlling the polarization properties of a photo-induced device in an optical waveguide and a method of investigating the structure of a light guiding body such as an optical waveguide are disclosed. A device, such as gratings, is written by exposing one side of the optical waveguide to light. The unexposed side is then exposed to an amount of light sufficient to impart the desired birefringence to the written device. The birefringence can be minimized in the written device by exposing the opposite side to light in an amount sufficient to minimize the amount of birefringence. The light guiding body is investigated by cleaving the elongated light guiding body, such as an optical waveguide, to expose its cross-section. The cleaved section is then treated to expose difference between the core and cladding. Treatment may include etching in an acid or base.

Abstract: An efficient light coupling apparatus for interconnecting two optical components. Light radiation from the first optical component, for example an optical light fiber is directed onto the plane surface of the second optical component, for example a passive waveguide. The light is directed onto the second optical component at a convenient angle such that it impinges on the plane surface of the second optical component at an incident angle. An angularly selective coupling means, for example a volume hologram is located between the first and second optical components for coupling a maximum amount of the light at the incident angle.

Abstract: The present invention comprises a system for condensing and collecting electromagnetic radiation having a primary reflector disposed on one side of an electromagnetic radiation source and a target disposed on the opposite side of the source. The primary reflector includes a concave reflecting surface portion, which preferably forms the entire surface of the reflector. The concave surface portion of the primary reflector, which is preferably of a substantially toroidal shape, defines an optical axis and a primary center of curvature disposed along the optical axis. The source of electromagnetic radiation is located approximately on the optical axis but axially offset a first distance from the center of curvature in a direction toward the concave surface portion.

Abstract: A V groove and guide grooves are defined in a ceramic substrate, and an optical fiber is fixedly disposed in the V groove by the ceramic substrate and a cover, thereby producing a first optical waveguide chip. A V groove and guide grooves are also defined in another ceramic substrate, and an optical fiber is fixedly disposed in the V groove by the ceramic substrate and a cover, thereby producing a second optical waveguide chip. The first optical waveguide chip has an end face inclined to the direction of propagation of light through the optical fiber thereof, and the second optical waveguide chip also has an end face inclined to the direction of propagation of light through the optical fiber thereof. The first and second optical waveguide chips are positioned relatively to each other by guide pins intimately placed in the guide grooves, and the inclined end faces extend substantially parallel to each other with an air layer interposed therebetween.

Abstract: A first optical waveguide chip has a ceramic substrate and a cover, and the ceramic substrate has a V groove and guide grooves with an optical fiber being fixed in the V groove. A second optical waveguide chip has a ceramic substrate and a cover, and the ceramic substrate has a V groove and guide grooves with an optical fiber being fixed in the V groove. The first and second optical waveguide chips have respective end faces inclined 62.degree. to the direction in which light is propagated through the optical fibers. The first and second optical waveguide chips are positioned by guide pins intimately fitted in the guide grooves.

Abstract: The sensor comprises at least one quartz body (1) sectioned from a quartz crystal, an optical fiber connected to the quartz body in at least one given length, and means for detecting changes in length of the optical fiber which are caused by piezoelectrically caused changes in shape of the quartz body in an electric field. It is shown how the mostly undesired temperature dependence of the sensor measurement signal can be influenced and, as the case may be, even eliminated in a purely passive manner by a mixture of the two independent piezoelectric coefficients d.sub.11 and d.sub.14 which contribute to the piezoelectrically caused change in dimension of the quartz body.

Abstract: A light input reflector for optical-fiber systems wherein at least 50% of the deviated luminous flux of the lamp hits the light entrance surface of the optical-fiber system.

Abstract: Optical waveguide isolator (121) for monolithic integration with semiconductor light emitting diodes such as Fabry-Perot or ring laser diodes. The present optical isolator (121), with optical input port (95) and output pod (96), comprises a branching waveguide coupler (56). This branching waveguide coupler (56) has a waveguide stem (60) splitted at one end into two waveguide branches (57, 58) such that a light wave fed via said input pod (95) into a first of these branches (58), is guided via the waveguide stem (60) and the output pod (96) out of the device. A light wave fed to the isolator's output pod (96) is guided along the stem (60) and coupled into the second waveguide branch (57).

Abstract: A laser radiation source apparatus comprises a laser source means for producing laser radiation; a stepped-index optical fiber; first coupling means for coupling the laser source means with one end of the stepped-index optical fiber; and second coupling means for coupling the other end of the stepped-index optical fiber with another fiber suitable for transmission of laser radiation. The stepped-index fiber optic includes a core suitable for transmission of laser radiation, which is encompassed by at least one cladding layer and a buffer layer, in which the refractive index value for the core is greater than the refractive index value for the cladding layer, and the refractive index value for the cladding layer is greater than the refractive index for the buffer layer, so that laser radiation transmitted into the cladding layer is transmitted through the fiber. Single index fibers having several diameters may be coupled to the apparatus.

Abstract: A fiber optic probe for detecting scattered light, with transmitting and receiving fibers having slanted ends and bundled together to form a bevel within the tip of the probe. The probe comprises a housing with a transparent window across its tip for protecting the transmitting and receiving fibers held therein. The endfaces of the fibers are slanted, by cutting, polishing and the like, so that they lie in a plane that is not perpendicular to the longitudinal axis of the respective fiber. The fibers are held in the tip of the probe using an epoxy and oriented so that lines normal to the slanted endfaces are divergent with respect to one another. The epoxy, which is positioned substantially between the transmitting and receiving fibers, is tapered so that the transmitting fiber, the epoxy and the receiving fiber form a bevel of not more than 20 degrees. The angled fiber endfaces cause directing of the light cones toward each other, resulting in improved light coupling efficiency.

Abstract: A method and apparatus for relatively moving energy across an array of optical fibers. The energy may be scanned across the fiber array. A dielectric mirror mounted on a galvanometer scanner is moved so as to cause successive pulses to irradiate different segments of the fiber optic array. As a result, each fiber receives radiation having sufficient fluence while reducing the energy per pulse (or the cw equivalent). Rather, than move the energy across the fiber array, the fiber array itself may be moved. One possible manner of movement is use of a piezo electric stack.

Abstract: An optical demultiplexing/multiplexing device made with a few stable components by easy fabrication processes, which provides a flat response over the specified frequency range.

Abstract: The invention relates to a method of reducing scattering of light emerging from an optical edge of an optical waveguide. According to the invention, the optical edge is maintained in intimate contact with an index matching substance which itself also forms or intimately contacts a further optical component. The invention also relates to a disposable holder suitable for use in the method.

Abstract: A fiber-optic amplifier for use with optical communications systems includes a light waveguide piece for amplifying an optical input signal. A pump light source is coupled to the amplifying light waveguide piece and includes a semiconductor laser for generating pump light for the amplifying light waveguide piece. A control device regulates the wavelength of the pump light generated by the semiconductor laser to be within a desired wavelength range so that the pump light is maximally absorbed in the amplifying light waveguide piece.

Abstract: This invention relates generally to the development of and a method of fabricating a micro optical fiber light source. An optical fiber micro-light source is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material. This process allows significant control of the size of the micro light source.

Abstract: An optical security system enables the integrity of a container seal to be remotely interrogated. A plurality of Bragg gratings is written holographically into the core of at least one optical fiber placed about the container seal, where each Bragg grating has a predetermined location and a known frequency for reflecting incident light. A time domain reflectometer is provided with a variable frequency light output that corresponds to the reflecting frequencies of the Bragg gratings to output a signal that is functionally related to the location and reflecting frequency of each of the Bragg gratings.

Abstract: Three types of temperature compensated fiber optic external cavity strain sensors and methods of operation thereof are disclosed as well as an intensity-based fiber optic external cavity sensor and system. The fiber optic external cavity sensors each comprise an input optical fiber and a wire bonded together in spaced axial alignment by a connecting sleeve wherein respective ends of the fiber and the wire face one another and are spaced apart a predetermined distance to define an air gap. The ends of the input fiber and wire form two reflective surfaces. The temperature compensation methods involve either keeping the air gap unchanged with respect to temperature variations or having a temperature sensitive reflector at the tip of the wire. An intensity-based external cavity sensor comprises an input fiber which is a single mode fiber. An optical bandpass filter is deposited at the end of the single mode fiber. A reflector is also provided at the end of the wire.

Abstract: Previous efforts to measure polarization dependent loss of optical components have been limited in uncertainty to more than 0.01 dB. This is because the power meter used in a test set contains polarization dependent loss which adversely affects the final readings. It is here disclosed that an unpumped erbium doped fiber can convert a received polarized signal into unpolarized amplified spontaneous emission of a longer wavelength if the fiber is of sufficient length to absorb the received signal. By locating the inventive unpumped erbium doped fiber upstream of the power meter of a test set, the polarized signal to the power meter is coverted to an unpolarized signal and, therefore, the polarization dependent loss of the power meter can not influence the measurement obtained.

Abstract: A technique for reducing signal degradation and fading within a long optical transmission by utilizing a rotating waveplate arrangement to rotate the SOP of an optical signal launched into the transmission system, and thereby minimize polarization dependent hole-burning ("PDHB"). This effectively reduces the degree of polarization of the launched optical signal, without degrading the noise and dispersion characteristics of the signal. The rate of waveplate rotation is chosen to ensure that the SOP of the launched signal does not remain at a particular SOP long enough to anisotropically saturate any optical amplifier employed within the transmission system, and give rise to PDHB.

Abstract: Apparatus for improving the coupling efficiency of a laser to a single mode fiber by means of an intermediate waveguide is disclosed. For uniform waveguides maximum improvement results when waveguide's mode field radii MFR is designed as the geometrical mean of the MFR of the laser and the MFR of the fiber. The apparatus can be extended to multi-stage couplers. Each successive stage is designed to have a spot size which is the geometric mean of the section before and after. With only a small number of stages significant improvement in coupling efficiency can be realized.

Abstract: An optical fiber tip for use in a laser delivery system comprising a distal end of an optical fiber having an exposed cylindrical core. A flat elliptical surface is formed across a distal end of said cylindrical core and intersects a center line of said cylindrical core at a predetermined angle. In one embodiment, a reflective coating is deposited on said flat elliptical surface such that a laser beam carried by said fiber will be reflected by said reflective coating. In another embodiment, said flat elliptical surface intersects said center line of said cylindrical core at an angle exceeding a critical angle necessary for said flat elliptical surface to totally reflect a laser beam carried by said optical fiber.

Abstract: An optical guide end-fire coupling apparatus including a light source section having a condenser lens system for converging a laser beam to be incident on an optical guide, having a first light incident end facet, of an optical guide device, having a second light incident end facet, and including an actuator for finely adjusting the position of the condenser lens system with respect to an optical, i.e. a z axis of the condenser lens system, an x axis and a y axis, which axes are all orthogonal with each other and a photodetector assembly for detecting a light intensity of a return beam of a laser beam which is emitted from the light source section and reflected by the second light incident end facet on which the first light incident end facet of the optical guide is facing, and for controlling the actuator in accordance with the detected light intensity so that the position of the actuator is adjusted with respect to the x, y and z axes.

Abstract: A method for interconnecting a waveguide (102), an optoelectronic component 101, and an electronic component (103). A first surface (108) is formed from a portion of cladding region(107) and a second surface (109) is formed from a portion of core region and a portion of the cladding region. A substrate (104) having electrical tracings (212', 213') is attached to the waveguide (102) so that an electronic component receiving area (111') and an optoelectronic component area (112') are attached to the first and second surface (108, 109) of the waveguide (102) respectively. An electronic component (103) and an optoelectronic component (101) are mounted to the electronic component receiving area (111') and the optoelectronic receiving area (112') respectively.

Abstract: The optical connection to a fiber-optics connected optoelectronic device mounted on a substrate is made by an optical fiber inserted in a hole through the substrate facing the component. The walls of the hole align and locate the fiber. The invention finds an application in the manufacture of a balanced optoelectronic receiver for a coherent detection fiber-optics transmission system.

Abstract: This invention relates to an apparatus and method for providing control of high power laser/fiber delivered beam quality. Such structures of this type, generally, allow the parameters of a high power fiber delivered beam to be determined such that the high power laser beam is injected into an optical fiber with the appropriate focal length lens.

Abstract: A fiber optic mixer is disclosed. A large diameter fiber has a curved radiation input end portion and a straight radiation output end portion. The length of the curved input end portion of the fiber is long enough to cause all entering radiation to hit the reflecting core boundary while the length of the straight output end portion is long enough to provide sufficient internal reflections to mix the radiation entering at the input end to produce a nearly zero correlation between an enterirg ray position and its position as an exiting ray. The fiber optic mixer can be used to efficiently couple radiation from the source or interferometer of a Fourier Transform Infrared Spectrometer (FT-IR) to a multiplicity of optical fibers so that each fiber receives substantially identical spectral, angular and intensity distributions of radiation.

Abstract: An optical apparatus functions as a laser catheter for removal, penetration or treatment of human tissue or other biotic material. The arrangement of the optical components, including the focal length of the lens and the spacing between the lens and the source of light is selected to yield an output beam having advantageous characteristics which are particularly suitable for medical laser treatment. Such characteristics include a relatively long beam throw, a long focal range, and a small output beam waist. A hollow tip, preferably conical in shape, is utilized to provide a tactile indicator as to the cutting action of the output beam.

Abstract: A hybrid fiber which, at the operating wavelength, has a desirable fiber dispersion characteristic and a relatively large effective area is provided. Hybrid fibers are constructed in accordance with the principles of the invention by splicing together a fiber with a large effective area but typically unsatisfactory fiber dispersion characteristics to a fiber having excellent dispersion characteristics but a smaller effective area. The resulting hybrid fiber has an increased effective area and desirable fiber dispersion characteristics at the low-loss operating wavelength.

Abstract: A system for interconnection of a stack of circuit boards, wherein each of at least a plurality of the circuit boards has an end region carrying one or more light transmitters or light receivers, an optical structure forming an interconnecting backplane for the circuit boards, the optical structure comprising a first surface carrying a multiplicity of hologram elements disposed to receive light beams from said light transmitters and to route said light beams to a second reflective surface where said light beams are reflected back to said hologram elements for routing to said light receivers.

Abstract: An optical pulse generating apparatus having a semiconductor laser medium and an external resonator comprising an optical waveguide path. A reflecting element in the optical guide path is given such a reflection wavelength characteristic as to suppress other components than the component of an oscillation main longitudinal mode, so that the level of the main longitudinal mode component is raised and optical pulses with a narrower spectrum width and pulse width are produced.

Abstract: A method, and device produced therewith, for improving the planarity of etched mirror facets 18 of integrated optic structures with non-planar stripe waveguides, such as ridge or groove diode lasers or passive devices such as modulators and switches. The curvature of the mirror facet surface at the edges of the waveguide due to topographical, lithographical and etch process effects, causes detrimental phase distortions, and is avoided by widening the waveguide end near the mirror surface thereby shifting the curved facet regions away from the light mode region to surface regions where curvature is not critical.

Abstract: An optical amplifier apparatus which amplifies a signal light in an optical fiber includes an optical fiber having a core containing a rare-earth dopant element and an excitation light source including a semiconductor laser for generating excited light and an optical amplifier utilizing a semiconductor laser for amplifying the excited light and supplying the amplified excited light to the optical fiber.

Abstract: An optical logic device based on the time-shift-keying architecture is described in which digital logic functions are realized by applying appropriate signal pulses to a nonlinear shift or "chirp" element whose output is supplied to a dispersive element capable of supporting soliton propagation. In an optical fiber realization of the optical logic device, two orthogonally polarized pulses are supplied to the combination of a moderately birefringent fiber acting as the nonlinear chirp element and a polarization maintaining fiber acting as the soliton dispersive delay element having a anomolous group velocity dispersion at the signal wavelengths of interest. A nonlinear frequency shift is created in one of the pulses in the former element through cross-phase modulation and, in turn, the frequency shift is translated into a temporal shift of the affected pulse in the latter element. These devices operate at switching energies approaching 1pJ.

Abstract: An optical coupler for coupling light between an end of a fiber-optic cable and the optical port of an electro-optic device, and an improved method for making the coupler. A silicon substrate is etched to form a groove dimensioned to hold the fiber-optic cable, with the end of the fiber-optic cable adjacent to the terminating surface of the groove. Alignment means are then formed on the working surface, and used to secure positioning means to the substrate at a predetermined position. The positioning means includes a positioning surface oriented to abut a reference surface of the electro-optic device. The electro-optic device is then mounted on the working surface, with its reference surface abutting the positioning surface. The alignment means is formed so that the optical port is positioned to efficiently couple light between the end of the fiber-optic cable and the optical port, via reflection off the terminating surface.

Abstract: An electronic module includes a front fin, a printed circuit board having connected terminals, a status display including a plurality of fiber optic guides which lead into the fin and serve as light-emitting elements, a front panel connector, and a front door attached to the front panel connector. The fin may include a bar on a housing shell which projects to the front side and of a counterpart bar on a housing cover. The plurality of fiber optic guides may be combined into one fiber optic comb. A swivel may be used to connect the front panel connector to the module. Flexible hinges may be used to connect the front door to the front panel connector and to mount the light-emitting elements to the printed circuit board.

Abstract: It has been discovered that tilted optical fiber endfaces useful in low-reflection optical fiber joints can be produced by cleaving, provided the fiber is twisted through an appropriate twist angle. By way of example, for a particular, commercially available single mode fiber, the normalized twist angle typically is in the range of 5-15 degrees/cm, resulting in a nominal tilt angle of the fiber endface in the approximate range 5-20 degrees.

Abstract: A laser light applicator comprises a laser light conductor fiber and a light guiding element of larger diameter than the fiber, distally connected thereto by means of a butt joint. The light conductor element is provided at its distal end with a ball head which has been formed with plane, blackened, ground surfaces converging to provide a wedge having at its top a truncated unblackened edge. The ball-head diameter is preferably between 1.5 and 2.0 mm, the plane surfaces being angled by between 54.degree. and 60.degree. with respect to each other.

Abstract: A novel optical fiber structure is described which includes an end thereof for transmitting optical signals and substantially reducing reflections of optical signals thereat wherein the fiber end has a substantially flat end surface disposed at an angle to a plane perpendicular to the transmission axis of the fiber equal to or greater than sin.sup.-1 (NA/n) where NA is the numerical aperture and n is the index of refraction of the fiber core material, and the fiber outer surface has adjacent the end surface a flattened portion of preselected depth and length whereby substantially all paraxial and meridional optical signals propagated along the fiber axis are transmitted through the end surface and skew rays transmitted along the fiber are substantially attenuated near the fiber end.