Abstract: An apparatus, composition, and method for producing an optical gain. The apparatus includes: an optical fiber having a core and a multiple cladding, the core being doped with Yb3+; a light source producing light at a wavelength in a range of from about 0.8 to about 1.06 microns to energize the yb3+ to produce laser action; and wherein the core is essentially devoid of Nd3+.

Abstract: The present invention features a light-pumped, single-mode, pulse- or continuous-wave amplifier, or a Q-switch, with each having a high-saturation output power. The amplifier or Q-switch has a light-pumped, optical fiber having active ions that are either annularly located within the cladding or adjacent the core/cladding interface. Pump-light and an input signal are coupled to the fiber via a dispersive or biconically-tapered coupler. The light-pumped fiber provides stored energy, with an induced emission in the excited-state population that is relatively low for the given amount of energy stored. The central part of the core both stores and propagates whatever light is present, due to induced emission, which takes place only in the annular region. The light that is incident on the fiber is of sufficient intensity so that, despite the low rate of induced emission per unit of light intensity, a significant power increase occurs.

Abstract: Device for use in adding or dropping light signals at predetermined center wavelengths to or from a wavelength division multiplex, fiber optic transmission system. The device includes an evanescent wave coupler having a coupling region formed from two single mode waveguides, the coupling region being formed so that there is substantially complete evanescent field coupling of light from one waveguide to the other in a predetermined wavelength band. Further, the device has a Bragg grating disposed in the coupling region in each of the waveguides.

Abstract: Device for use in adding or dropping light signals at predetermined center wavelengths to or from a wavelength division multiplex, fiber optic transmission system. The device includes an evanescent wave coupler having a coupling region formed from two single mode waveguides, the coupling region being formed so that there is substantially complete evanescent field coupling of light from one waveguide to the other in a predetermined wavelength band. Further, the device has a Bragg grating disposed in the coupling region in each of the waveguides.

Abstract: Device for use in adding or dropping light signals at predetermined center wavelengths to or from a wavelength division multiplex, fiber optic transmission system. The device includes an evanescent wave coupler having a coupling region formed from two single mode waveguides, the coupling region being formed so that there is substantially complete evanescent field coupling of light from one waveguide to the other in a predetermined wavelength band. Further, the device has a Bragg grating disposed in the coupling region in each of the waveguides.

Abstract: A system for producing an optical gain, the system including a host having a light conducting path doped with thulium, holmium, and at least one rare earth selected from the group consisting of europium and terbium in respective amounts sufficient to produce an optical gain by energizing the thulium to a .sup.3 H.sub.4 state to produce an optical gain by a .sup.3 H.sub.4 -.sup.3 F.sub.4 transition, producing a 1.47 .mu.m wavelength output. There is subsequent energy transfer from the .sup.3 F.sub.4 state of the thulium to a .sup.5 I.sub.7 state of the holmium, and energy transfer from the .sup.5 I.sub.7 state to the rare earth selected from the group consisting of europium and terbium. The system can include oscillator, amplifier, and superluminescence source configurations. A method for making and a method for using the system are included.

Abstract: A light source for an interferometric fiber optic gyroscope ("IFOG") includes a thulium (Tm.sup.+++) doped optical fiber which exhibits superluminescence in a wavelength region substantially centered at about 1.8 microns.

Abstract: Embodiments of the present invention are sulfur rich glass compositions comprising germanium, gallium and sulfur, which glass compositions have a low energy phonon spectrum and which glass compositions serve as a host for active materials in fabricating light sources such as fiber laser oscillators, light amplifiers, and superluminescent sources. In particular, such a laser oscillator, light amplifier or superluminescent source is comprised of an inventive glass composition which is doped with rare earth ions such as Pr.sup.3+ or Dy.sup.3+ for producing light output at wavelengths, among others, substantially at 1.3 um. Further embodiments of the present invention are light sources such as laser oscillators, light amplifiers and superluminescent sources which have emissions substantially at 1.3 um and which are comprised of an inventive glass composition which is doped with Dy.sup.3+ and Yb3+ ions, wherein Dy.sup.3+ ions are pumped by energy transfer from Yb3+ ions.

Abstract: A Bragg grating is made in an optical path composed of material exhibiting change in index when exposed to radiation of an actuating frequency by passing radiation from a source of such actuating frequency through a mask with periodic variation in transmission to expose the material of the path to a diffraction pattern.

Abstract: A fiber superfluorescent light source is disclosed which suppresses laser cillations without interfering with the pump light or the super luminescence. In a preferred embodiment of the invention, the fiber superfluorescent light source comprises a laser diode array for providing a pump beam at a wavelength of 0.81 microns, a first fiber doped with neodymium activator ions and being responsive to the pump beam for providing a spontaneous emission at a wavelength of 1.06 microns, and a second fiber optically coupled between the laser diode array and the first fiber for passing the pump beam therethrough to the first fiber to enable the first fiber to spontaneously emit light at the 1.06 micron wavelength and for suppressing backemissions of the 1.06 micron wavelength from the first fiber toward the laser diode array to prevent back reflection from the laser diode array and oscillations in the first fiber.

Abstract: A system for producing an optical gain. The system includes an optical fiber having a core and a cladding, the core being doped with Pr.sup.3+ ; and a source producing light to energize the Pr.sup.3+ to the .sup.1 G.sub.4 state and produce an optical gain by a .sup.1 G.sub.4 -.sup.3 H.sub.5 transition at a wavelength in the range of 1.25 to 1.34 microns. The system also includes a method of making and a method of using the same.

Abstract: A system for producing an optical gain, the system including a host having a light conducting path doped with thulium, holmium, and at least one rare earth selected from the group consisting of europium and terbium in respective amounts sufficient to produce an optical gain by energizing the thulium to a .sup.3 H.sub.4 state to produce an optical gain by a .sup.3 H.sub.4 -.sup.3 F.sub.4 transition, producing a 1.47 .mu.m wavelength output. There is subsequent energy transfer from the .sup.3 F.sub.4 state of the thulium to a .sup.5 I.sub.7 state of the holmium, and energy transfer from the .sup.5 I.sub.7 state to the rare earth selected from the group consisting of europium and terbium. The system can include oscillator, amplifier, and superluminescence source configurations. A method for making and a method for using the system are included.

Abstract: A tellurite glass particularly usable for an amplifier or oscillator utilizing an optical fiber or other guided wave structure. In approximate terms, the glass contain between 58 and 84 molar % of TeO.sub.2, up to 24 molar % Na.sub.2 O, and between 10 and 30 molar % of ZnO. Other alkali and divalent metals may be substituted for the Na and Zn respectively. Combinations of these tellurite glasses can be formed as an optical fiber (10) having a core (12) with a higher refractive index than that of the cladding (14). The tellurite glass of the core, when composed of at least 0.05 molar % Na.sub.2 O, can be doped with large amounts of Er, Pr, or Nd to act as a fiber amplifier at 1.5 or 1.3 .mu.m when pumped with light of a specified shorter wavelength. The core can be doped with other rare-earth metals which would provide optical amplifiers or oscillators at wavelengths appropriate to their lasing characteristics.

Abstract: An integrated optics print head includes an array of indepenedently driven semiconductor lasers disposed on a common substrate with their outputs coupled to an integrated waveguide structure. The integrated waveguide structure includes a multiplicity of "S" shaped, low-loss waveguides which have substantially the same length. Further, in order to reduce crosstalk, the region of the waveguide structure at the output where all the waveguides are in close proximity is made as short as possible while maintaining a parallel relation between the waveguide outputs.

Abstract: A method for fabricating optical fibers having a rare-earth doped core and a fused silica cladding includes inserting a rare-earth doped soft glass rod into a fused silica tube, the ratio of the outer diameter (OD) to the inner diameter (ID) of the fused silica tube being at least 2 and as large as 50; heating the rod and tube combination in a furnace to selectively volatilize volatile constituents of the soft glass rod which are responsible for the low softening point so that the final composition of the core consists predominantly of SiO.sub.2 and the desired dopants such as rare earths, alkaline earths or other low vapor pressure materials; and drawing the perform into an optical fiber.

Abstract: Apparatus for coupling radiation into a single-mode core of an optical fiber laser has a single-mode core disposed within a relatively large, multimode cladding at a location which is displaced from the center of the cross-section of the cladding. The cladding is surrounded by a further layer to prevent radiation from propagating out of the cladding. In addition, the apparatus preferably has slight bends to enhance the coupling of radiation from the cladding into the single-mode core. A further embodiment has a single-mode fiber laser disposed in a relatively large, multimode, slab cladding which, in turn, is surrounded by another cladding to prevent radiation from propagating out of the large cladding.

Abstract: An optical fiber has a dielectric periodic index of refraction phase grating established in its core by intense angled application of several transverse beams of ultraviolet light, enabling the establishment of a distributed, spatially resolving optical fiber strain gauge.

Abstract: A distributed, spatially resolving optical fiber strain gauge in which the core of the optical fiber is written with periodic grating patterns effective for transmitting and reflecting light injected into the core. Spectral shifts in the transmitted and reflected light indicate the intensity of strain or temperature variations at positions of the grating corresponding to the associated wavelengths of injected light.

Abstract: An optical fiber laser comprising a nearly pure fused silica glass, neodymium doped active core within a cavity in the form of a single mode optical fiber. The gain cavity is end pumped at a nominal wavelength of 0.8 microns and its length and neodymium concentration are adjusted to maximize pump absorption and minimize concentration quenching. Dichroic mirrors are preferably integrally formed on ends of the cavity and have reflection characteristics selected so that the laser has an output at a nominal wavelength of 1.06 microns.

Abstract: An optical fiber laser comprising a gain cavity in the form of a single mode optical fiber with integrally formed dichroic mirror end sections to provide feedback. The fiber core comprises a host material of silicate glass preferably doped with 0.01 to 1 weight percent of just erbium oxide as a lasing medium. The laser is end pumped at approximately 1.49 micrometers with a laser diode, preferably InGaAsP, and has an output at 1.54 micrometers.