Abstract: An optical phase modulator comprising a plurality of polarizing waveguides having a layered stack including a core between at least one layer of cladding material, wherein the core is constructed of electro-optic material(s), wherein the layers of cladding materials having lower indices of refraction than the core for guided mode, wherein the layers of cladding materials having higher indices of refraction than the core for non-guided mode, at least one electrode coupled to at least one waveguide including a modulating polarizing region, at least one waveguide having a non-modulating region and a modulating region, a substrate dimensioned and configured to integrate a plurality of optical components, wherein the optical components include a plurality of polarizing waveguide(s), a waveguide having a non-modulating region and a modulating region, coupler/splitter(s), electrode(s), and a waveguide configuration including a first polarizing waveguide, a second polarizing waveguide and a third polarizing waveguide

Abstract: A polymer phase modulator having a plurality of polarizing waveguides having a layered stack including a core between at least one layer of cladding material, wherein the core is constructed of electro-optic material(s), wherein the layers of cladding materials having lower indices of refraction than the core for guided mode, wherein the layer of cladding material having higher indices of refraction than the core for non-guided mode, at least one waveguide having a non-modulating polarizing region, a substrate dimensioned and configured to integrate a plurality of optical components, wherein the optical components include a plurality of polarizing waveguide(s) and non-polarizing waveguide(s), a waveguide having a polarizing non-modulating region and a non-polarizing modulating region, coupler/splitter(s), electrode(s), and a waveguide configuration including a first polarizing waveguide, a coupler/splitter including a plurality of splitter ports, a second polarizing waveguide and a third polarizing waveguide.

Abstract: An optical transceiver comprising an optical bench including of a waveguide on a substrate, a light source, a system of transceiver module waveguides, a waveguide coupler, a fiber, and a detector.

Abstract: Photosensitive optical materials are used for establishing more versatile approaches for optical device formation. In some embodiments, unpatterned light is used to shift the index-of-refraction of planar optical structures to shift the index-of-refraction of the photosensitive material to a desired value. This approach can be effective to produce cladding material with a selected index-of-refraction. In additional embodiments gradients in index-of-refraction are formed using, photosensitive materials. In further embodiments, the photosensitive materials are patterned within the planar optical structure. Irradiation of the photosensitive material can selectively shift the index-of-refraction of the patterned photosensitive material. By patterning the light used to irradiate the patterned photosensitive material, different optical devices can be selectively activated within the optical structure.

Abstract: A fluidic waveguide comprising a container and a fluid that fills said container, wherein said fluid has a refractive index greater than the refractive index of the wall of said container and wherein said fluid can act as a waveguide for electromagnetic radiation when contacted therewith is disclosed. A corresponding fluidic lightguide along with devices that function as composite waveguides and lightguides are described. Assays utilizing this waveguide for biochemical, chemical, and other kinds of analyzes are also disclosed.

Abstract: A waveguide configuration comprising a core, a first cladding, a second cladding, and a buffer. The core includes an index of refraction and an acoustic shear velocity. The first cladding extends about the core and has an acoustic shear velocity which is less than that of the core and an index of refraction which is less than the core. The second cladding extends about the first cladding. The second cladding has an acoustic shear velocity which is greater than that of the first cladding and less than the acoustic shear velocity of the core. The second cladding has an index of refraction which is less than that of an optical mode. The buffer extends about the second cladding.

Abstract: The present invention relates to an optical fiber having a structure which allows further improvements to be made both in terms of lower reflectance and narrower bandwidth, and to a fiber grating type filter including the optical fiber. The optical fiber applied to the fiber grating type filter comprises a core region extending along a predetermined axis, and a cladding region provided on an outer periphery of the core region. The core region does not contain any photosensitive dopant which contributes to predetermined wavelength light photosensitivity as a glass property, but a part of the cladding region contain such a photosensitive dopant. By means of this composition, it is possible to form a grating, which has a grating plane slanted by a predetermined angle with respect to the optical axis, in a part of the cladding region surrounding the core region.

Abstract: A method for the preparation of an optical waveguide device characterized in that it comprises a first step for forming a first resin film on a substrate provided thereon with a lower clad layer; a second step for patterning the first resin film into a shape of an optical waveguide to thus form a core layer; a third step for forming a second resin film by coating the surfaces of the lower clad layer and the core layer with a solution containing a material for forming the second resin film according to the spin-coating method in such a manner that the thickness of the resulting film as measured from the upper surface of the lower clad layer and as determined after drying ranges from 3 to 10 times the thickness of the core layer and then drying the coated layer; and a fourth step for removing the second resin film in such a manner that the thickness of the second resin film as determined from the upper surface of the lower clad layer is less than 3 times that of the core layer and that the second resin film thu

Abstract: A light pipe with uniform side-light emission has a core comprising a polymer, and a fluoropolymer cladding on the core with a lower refractive index than the core. Light-scattering material is distributed within the core along an active section of light pipe in which side-light emission is desired, with a density gradient chosen to achieve uniform side-light emission. Another light pipe with uniform side-light emission has a core comprising a polymer, and a fluoropolymer cladding on the core with a lower refractive index than the core. Light-scattering material is distributed within at least one of the cladding and the core along an active section of light pipe in which side-light emission is desired, with a density gradient chosen to yield uniform side light emission, and substantially only in a radial swath, along the longitudinal axis of the light pipe, of substantially less than 360 degrees.

Abstract: In general, in one aspect, the disclosure features a fiber waveguide having a waveguide axis, including a core extending along the waveguide axis and a confinement region extending along the waveguide axis surrounding the core. The confinement region includes a periodic structure along a radial direction extending from the waveguide axis and each period in the periodic structure includes a layer of a chalcogenide glass and a layer of a polymer.

Abstract: A doped barrier region included in an optical phase shifter is disclosed. In one embodiment, an apparatus according to embodiments of the present invention includes a first region of an optical waveguide and a second region of the optical waveguide. The second region of the optical waveguide includes a higher doped region of material and a lower doped region of material. An insulating region disposed between the first and second regions of the optical waveguide is also included. A first portion the higher doped region is disposed proximate to the insulating region. A dopant barrier region is also included and is disposed between the higher and lower doped regions of the second region of the optical waveguide.

Abstract: The invention provides an optical waveguide material whose refractive index can be tailored without changing the ratio of Ta and Nb. An optical waveguide of this invention comprising an under-clad layer 1 and a core 2 that is formed on the under-clad layer 1 and has a higher refractive index than that of the under-clad layer 1 is shown. For example, KTN (KTa1?xNbxO3) is used as the core 2, and a material that is obtained by substituting at least one element selected from the group consisting of Zr, Hf, and Sn for a portion of one element of the constituent elements of KTN and has the same perovskite type crystal structure as KTN is used as the clad. The refractive index of KTN can be reduced considerably, and this controllability widens the degree of freedom in the design of optical waveguide devices.

Abstract: An optical fiber for transmitting light, said optical fiber having an axial direction and a cross section perpendicular to said axial direction, said optical fiber comprising: (1) a first core region comprising a first core material having a refractive index Nco,1; (2) a microstructured first cladding region surrounding the first core region, said first cladding region comprising a first cladding material and a plurality of spaced apart first cladding features or elements that are elongated in the fiber axial direction and disposed in the first cladding material, said first cladding material having a refractive index Ncl,1 and each said first cladding feature or element having a refractive index being lower than Ncl,1, whereby a resultant geometrical index Nge,cl, 1? of the first cladding region is lowered compared to Ncl,1; (3) a second core region surrounding said first cladding region, said second core region comprising a second core material having a refractive index Nco,2, and (4) a second cladding regio

Abstract: The present invention relates to optical confinements, methods of preparing and methods of using them for analyzing molecules and/or monitoring chemical reactions. The apparatus and methods embodied in the present invention are particularly useful for high-throughout and low-cost single-molecular analysis.

Abstract: A coated optical fiber can have a primary coating and a secondary coating, where the primary coating can have good microbending resistance and is obtained by curing a composition having a high cure speed. In one example, a coated optical fiber can include as optical fiber, a primary coating and a secondary coating. The optical fiber can have an attenuation increase of less than 0.650 dB/km at 1550 nm, with the primary coating having a modulus retention ratio of at least 0.5, a glass transition temperature of ?35° C., and where the primary coating is obtained by curing a primary coating composition having a cure dose to attain 95% of the maximum attainable modulus of less than 0.65 J/cm2.

Abstract: An optical fiber includes a core, a cladding layer, and an overclad layer that has a plurality of nano-particles the core.

Abstract: An optical fiber includes a core, and a cladding layer that has a plurality of nano-particles around the core.

Abstract: The present invention is concerned with an optical cable with improved tracking resistance comprising at least one optical fiber and an outer sheath which comprises a polymeric material, characterized in that the polymeric material forms a matrix for the sheath and consists of a multimodal olefin polymer obtained by a coordination catalyzed polymerization, and in that the total composition of the sheath comprises 15–40% by weight of a metal hydroxide, preferably magnesium hydroxide and/or aluminium hydroxide, and 0.01–0.9% by weight of carbon black.

Abstract: A method of producing optical elements using a substrate having a recess, which is capable of easily removing a film in the recess, and optical elements formed. The optical element comprises a substrate 1, an optical waveguide structure layer 10 of resin disposed in a part of the region on the substrate 1, and a recess 21 formed in the region where the optical waveguide structure layer 10 is not disposed. The optical waveguide structure layer 10 includes an optical waveguide 4 and a clad layer. A coupler layer is disposed between the substrate 1 and the optical waveguide structure layer 10, and the film thickness distribution range of the coupler layer in the region below the optical waveguide 4 is such that the minimum film thickness is not more than 30 angstroms and the maximum film thickness is not less than 20 angstroms.

Abstract: Jacket tubes of synthetically produced quartz glass as a semi-finished product for producing an outer cladding glass layer of an optical fiber are generally known. The invention relates to an improvement of a jacket tube in terms of inexpensive producibility and of suitability as a semi-finished product for optical fibers having a low optical attenuation. According to the invention this object is achieved by a jacket tube in which the quartz glass has a content of metastable OH groups of less than 0.05 wt ppm and a content of anneal-stable OH groups of less than 0.05 wt ppm.

Abstract: A polymer optical waveguide has a substrate, a buffer layer formed on the substrate, and a polymer waveguide main body formed on the buffer layer. The buffer layer is made of a polymer material that can absorb a difference in thermal expansion coefficient between the substrate and the polymer optical waveguide.

Abstract: A magneto-optical device includes a waveguide structure that has at least one cladding region and core region. The cladding region and core region comprise semiconductor alloy materials. Either the at least one cladding region or the core region is doped with ferromagnetic materials so as to increase the magneto-optical activity of the device.

Abstract: A photonic crystal and a producing method thereof are provided. The photonic crystal includes at least two media of different refractive indices formed on a semiconductor substrate. One of the media is periodically arranged in another one of the media. The photonic crystal has a cleaved surface on its side. The directions of primitive translation vectors representing the periodic arrangement directions of the one medium are at desired angles with the cleaved surface. Preferably, the direction of at least one of the primitive translation vectors is in parallel with the cleaved surface.

Abstract: Disclosed is an optical fiber having a core of SiO2 doped with fluorine and an alkali metal oxide dopant. The alkali metal oxide is selected from the group consisting of K, Na, Li, Cs and Rb and is provided in amount of at least 20 ppm wt. %. The fiber has an inner cladding surrounding the core, which also includes fluorine. A relative refractive index of the inner cladding (?2%), measured relative to pure silica, is preferably between ?0.39% and ?0.7%. The fiber preferably exhibits attenuation at 1550 nm of less than or equal to 0.178 dB/km.

Abstract: A double-coated optical fiber and method includes providing a core that serves as a light transmission medium. A cladding surrounds the core and has a smaller reflective index than the core. A primary coating layer is formed of a UV-cured polymer around the clad, and a secondary coating layer is formed of a UV-cured polymer around the primary coating layer, to a thickness ranging from about 22 to 37.5 ?m in order to obtain a coating strip force ranging from about 1.0 to 1.63 N and a dynamic stress corrosion parameter ranging from 20 to 29. The primary and secondary coating layers can be formed by a wet on wet or wet on dry process.

Abstract: A clad is produced by polymerizing methyl methacrylate and (meth)acrylic acid ester having alicyclic hydrocarbon group. A core is produced by an interfacial-gel-polymerization method. A first covering layer having a thickness being less than 500 ?m is formed on an outer surface of the clad to produce a single-fiber optical cable. A plurality of the single-fiber optical cables are bundled. A gap between the single-fiber optical cables is infused with a filler. The bundled single-fiber optical cables are covered with a second covering layer to produce a multi-fiber optical cable. Since the covering layer is thin, the multi-fiber optical cable has excellent flexibility and reduced bending loss.

Abstract: This invention provides a process for producing a three-dimensional polyimide optical waveguide, which comprises: (I) irradiating a polyamic acid film with a laser beam while converging the laser beam at an inside portion of the film and relatively moving the light convergence point, the polyamic acid film containing: (a) a polyamic acid obtained from a tetracarboxylic dianhydride and a diamine; and (b) per 100 parts of the polyamic acid, from 0.5 part by weight to less than 10 parts by weight of a specific 1,4-dihydropyridine derivative represented by formula (I): and then, (II) heating the polyamic acid film to imidize the polyamic acid, thereby obtaining an optical waveguide having a continuous core region where the refraction index has been changed, in the thus formed polyimide film.

Abstract: A waveguide configuration comprising a core, a first cladding, a second cladding and a buffer. The core includes an index of refraction and a shear velocity. The first cladding extends about the core, has a shear velocity that is less than that of the core and has an index of refraction which is less than the core. A second cladding extends about the first cladding and has a shear velocity which is greater than that of the first cladding. An optical mode of the waveguide configuration has an index of refraction greater than that of the second cladding. The buffer extends about the second cladding. The core comprises one of a rare-earth dopant and an undoped glass fiber. The first cladding is selected from the group consisting of: Boron doped glass fiber, Fluorine doped glass fiber, and, Boron and Fluorine doped glass fiber. The second cladding has a higher relative doping concentration of Boron, Fluorine, or Boron and Fluorine than the first cladding and also contains Aluminum.

Abstract: Optical waveguide fiber having low water peak as well as optical waveguide fiber preforms and methods of making optical waveguide fiber preforms from which low water peak and/or low hydrogen aged attenuation optical waveguide fibers are formed, including optical waveguide fiber and preforms made via OVD. The fibers may be hydrogen resistant, i.e. exhibit low hydrogen aged attenuation. A low water peak, hydrogen resistant optical waveguide fiber is disclosed which exhibits an optical attenuation at a wavelength of about 1383 nm which is less than or equal to an optical attenuation exhibited at a wavelength of about 1310 nm.

Abstract: A lower cladding layer is laminated on a substrate and constituted of at least one layer. A light absorption layer is laminated on the lower cladding layer. An upper cladding layer is laminated above the light absorption layer and constituted of at least one layer. A light incident end surface is provided on at least one of the substrate and the lower cladding layer, and, when a light is made incident at a predetermined angle, enables the light to be absorbed in the light absorption layer and to be output as a current. An equivalent refractive index of the at least one of the substrate and the lower cladding layer is larger than that of the upper cladding layer. The predetermined angle is an angle enabling a light incident into the light absorption layer to be reflected at a lower surface of the upper cladding layer.

Abstract: Provided are compositions suitable for use in forming a flexible optical waveguide. The compositions include a polymer that has units of the formula (R1SiO1.5) and (R22SiO), wherein R1 and R2 are the same or different, and are substituted and/or unsubstituted organic groups, and wherein the (R22SiO) units are present in an amount of 14 wt % or more based on the polymer; and a plurality of functional end and/or internal groups. Also included is a component for altering the solubility of the composition upon activation. The solubility of the composition in a dried state is alterable upon activation of the component such that the composition is developable in an aqueous developer solution. Also provided are flexible optical waveguides, methods of forming flexible optical waveguides and electronic devices that include a flexible optical waveguide.

Abstract: The stepped optical fiber has a core glass member and a surrounding cladding glass member. It has a high numerical aperture (NA)?0.50. The core glass member preferably has a zinc-containing composition including, in % by weight, SiO2, 42 to 53; ZnO, 16 to 38; PbO, 1 to 20; Na2O, <14; K2O, <12; with a sum of ZnO and PbO?30 and a sum of Na2O and K2O is ?2. The cladding glass composition, which is compatible with this core glass, includes, in percent by weight, SiO2, 60 to 72; B2O3, <20; Al2O3, <10; Na2O, <18; and K2O, <15. The resulting optical fiber has low attenuation, very neutral color transmission and low manufacturing costs. Other cladding glass compositions resulted in considerably poorer properties with too much crystallization at the core glass boundary layer. Environmentally-friendly, lead-free embodiments of the core glass were also prepared having even lower aperture values of ?0.48.

Abstract: Provided are compositions suitable for use in forming a flexible optical waveguide. The compositions include a polymer, having units of the formula (RSiO1.5), wherein R is a substituted or unsubstituted organic group, and a plurality of functional end groups. A first component is provided for altering the solubility of the composition in a dried state upon activation. A second component contains a plurality of functional groups chosen from hydroxy, amino, thiol, sulphonate ester, carboxylate ester, silyl ester, anhydride, aziridine, methylolmethyl, silyl ether, and combinations thereof. The second component is present in an effective amount to improve flexibility of the composition in a dried state before and after activation. Also provided are flexible optical waveguides, methods of forming flexible optical waveguides and electronic devices that include a flexible optical waveguide.

Abstract: Provided are compositions which include a polymer, having units of the formula (RSiO1.5), wherein R is a substituted or unsubstituted organic group, and a plurality of functional end groups. A first component is provided for altering the solubility of the composition in a dried state upon activation. A second component contains a plurality of functional groups chosen from epoxides, oxetanes, vinyl ethers and combinations thereof. The second component is present in an effective amount to improve flexibility of the composition in a dried state before and after activation. Also provided are flexible optical waveguides, methods of forming flexible optical waveguides and electronic devices that include a flexible optical waveguide.

Abstract: An optical fiber includes a coating comprising a cross-linked network comprising the reaction product of monomers and oligomers and at least one polymer dispersed or interpenetrated in the cross-linked network. The oligomer and polymer components used are at least partially fluorinated. The fiber-coating composition of the invention presents a refractive index that is low while satisfying the conditions for industrial fiber-drawing.

Abstract: A resin liquid is provided which is used to produce an optical fiber coating layer which does not degrade over time in long-period transmission characteristics of the optical fiber. An optical fiber in which long-period transmission characteristics do not degrade is also provided. In order to achieve these objects, the present invention provides a resin liquid for an optical fiber coating layer containing at least one resin, wherein the resin liquid contains fewer than 500 pieces of extraneous material per 1 ml of the resin liquid, which have a minimum length of 0.5 ?m or more and a hardness greater than a hardness of the resin liquid after curing.

Abstract: Waveguides are disclosed (and other devices and materials including but not limited to hydrophobic coatings, passivation materials, glob top materials, underfill materials, dielectric materials for IC and other applications, microlenses and any of a wide variety of optical devices) that benefit by a high hydrophobicity and high stability and, among other things. In one embodiment of the invention, a method for making a waveguide comprises: forming a lower cladding layer on a substrate; forming a core layer after the lower cladding layer; and forming an upper cladding layer after the core layer; wherein the lower cladding layer, core layer and/or upper cladding layer is hydrophobic and results, if exposed to water, in a water contact angle of 90 degrees or more.

Abstract: A doped barrier region included in an optical phase shifter is disclosed. In one embodiment, an apparatus according to embodiments of the present invention includes a first region of an optical waveguide and a second region of the optical waveguide. The second region of the optical waveguide includes a higher doped region of material and a lower doped region of material. An insulating region disposed between the first and second regions of the optical waveguide is also included. A first portion the higher doped region is disposed proximate to the insulating region. A dopant barrier region is also included and is disposed between the higher and lower doped regions of the second region of the optical waveguide.

Abstract: The present invention concerns an optical guide (100) comprising an amplifier medium including: a core (10) in a main matrix of a transparent material, the main matrix containing particules (1, 2), each particule being formed of a submicronic matrix distinct from the main matrix and doped by an active metal element, an external guiding cladding (11) in contact with the core (10). The size of the particules (1, 2) is smaller than 20 nm. The present invention also concerns a method for producing this guide.

Abstract: An optical waveguide includes a clad of clad glass and a core of core glass. The clad glass includes gallium, lanthanum, and sulfur. The clad glass may include gallium sulfide and lanthanum oxide. The clad glass may also include lanthanum fluoride. The core glass includes gallium, lanthanum, sulfur, oxygen, and fluorine. The core glass may include gallium sulfide, lanthanum oxide, and lanthanum fluoride. An optical fiber perform is also disclosed.

Abstract: An optical fiber has a fiber core with a higher refractive index and a cladding surrounding the core with a lower refractive index. The fiber core is made of a multi-component oxide glass composition which consists of a glass-forming component and two Raman-active components. The glass former is SiO2 and the Raman active components are of Li2O and Nb2O5. The concentration of the glass former is between 30 and 90 mol % and of the Raman active components is up to 50 mol % in total. The composition may further include a glass-modifying component of alkaline such as Li2O, Na2O, K2O, Rb2O, Cs2O or earth-alkaline such as BeO, MgO, CaO, SrO, BaO in a concentration of up to 40 mol %.

Abstract: An optical fiber (1?) having at least one Bragg grating (11), the fiber comprising a core (2) surrounded successively by cladding (3) and by a coating (4), the grating being obtained by being written directly in the core and/or the cladding of the fiber through the coating which is made of a material that is substantially transparent to ultraviolet type radiation used for writing the grating, and wherein the material of the coating contains a first polymer network interpenetrated by a second polymer.

Abstract: An optical waveguide comprising cladding 1 and core segment 20 buried in cladding 1 and serving as a waveguide, wherein a combination of glass material constituting the core segment 20 and another glass material constituting the cladding 1 is so selected that an absolute value of difference in coefficient of thermal expansion between these materials (?1-?2) is within a range of 0 and 9×10?7° C., where ?1 denotes a coefficient of thermal expansion of the former material and ?2 denotes that of the latter material.

Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1-xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1-xO3 film. The KTaxNb1-xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1-xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.

Abstract: Telecommunication cable having a tubular element, in particular a buffer tube housing at least one transmission element. The tubular element has a polymeric composition which allows an easy tearing of the element, in order to get access to the transmission element housed therein. The tubular element is made from a polymeric composition having a heterophasic olefin copolymer which has at least one amorphous phase having sequences deriving from copolymerization of at least two different olefin monomers, at least a first crystalline phase having sequences deriving from the homopolymerization of a first olefin monomer and at least a second crystalline phase having sequences deriving from the homopolymerization of a second olefin monomer.

Abstract: A light guide is disclosed and includes a flexible elongated tube having an inner surface and first and second ends. A non-supercritically dried hydrophobic aerogel film is affixed to the inner surface of the tube as a cladding layer, and a fluid core is disposed within the tube. The fluid core has a refractive index greater than the refractive index of the aerogel cladding film.

Abstract: The present invention relates to an optical device comprising an ionic conductor and a pair of electrodes, the ionic conductor being made of a material that is transparent to light and contains mobile ions and the electrodes being suitable for absorbing and desorbing the ions and being in ionic contact with the ionic conductor. The refractive index in at least a zone of the ionic conductor can be varied under the effect of the voltage applied between the electrodes. The electrodes contain an electrochemically active material selected from an active carbon, a conductive polymer, and an insertion material suitable for inserting ions in its structure.

Abstract: A plastic optical fiber and a method for producing the same is disclosed. The plastic optical fiber is formed as a fiber of core-cladding structure. A protective layer or shield layer may be provided on the outer surface of the optical fiber of core-cladding structure for improving thermal resistance of the optical fiber and protecting the optical fiber from air and moisture. The plastic optical fiber uses fluorinated plastic, which contains a rare earth component as a core material, and a cladding material, which does not comprise a rare earth component but essentially consists of a polymer chain, which essentially consists of bonded —[CF2]n— monomers and has a refractive index lower than that of the core material. The optical fiber is produced by a melting-drawing technique.

Abstract: Disclosed herein is an optical fiber including a core doped with first metal ions; and a cladding formed so as to surround the core and doped with second metal ions selected so that the absorption coefficient in a transition wavelength band of first transition of the first metal ions is greater than the absorption coefficient in a transition wavelength band of second transition of the first metal ions. The amplification of light due to the first transition is suppressed, and at least the amplification or oscillation of light due to the second transition is effected. Also disclosed are an optical amplification/oscillation device, a laser light generating device, and a laser display unit, and a color laser display unit each employing the optical fiber.

Abstract: A fiber amplifier in which the active core is surrounded by a cladding and coupling of radiation between a core mode and cladding modes is suppressed to minimize cladding mode losses in a short wavelength range. An index profile is established in the active core and in the cladding such that the core exhibits a loss above a cutoff wavelength ?c and positive gains in the short wavelength range below the cutoff wavelength ?c. Suppression of cladding mode losses is achieved by an arrangement for suppressing the coupling of radiation in the short wavelength range between a core mode supported the active core and a cladding mode supported by the cladding. The arrangement for suppressing can include an absorbing material or a scattering material distributed in the cladding. The arrangement for suppressing can include a non-phase-matched length section of the fiber amplifier in which the core mode and the cladding modes are not phase matched.