DE202011107213U1 - Optical isolators with spectral conversion of light and generation of laser radiation - Google Patents

Abstract

Optical isolator with spectral light conversion and generation of laser radiation, comprising a spectral light converter forming a spatial unit, spectral filter and an optical substrate with an optical diode function, with radiation from UV to the near infrared spectral range incident on the spectral light converter at longer wavelengths (down-conversion ) and / or wavy spectrally shorter (up-conversion) is emitted as isotropic or laser radiation and optically passes the optical isolator in the forward direction and is completely absorbed or blocked in the reverse direction.

Description

The invention relates to the optical communication and computer technology, the optical information processing and transmission and the optical laser and measurement technology.

An optical isolator, which is also referred to as an optical diode, represents an optical component, which is the transmission of light at a defined wavelength - as z. B. laser present or in a wavelength range only in one direction (forward direction) allowed and in the opposite direction (reverse direction) is largely optically opaque (optically unidirectional diode behavior). Optical isolators are indispensable in optical technologies and serve to prevent optical feedback, the z. B. can interfere with the function of lasers sensitive and prevent further interference of optical systems by reflected and scattered light.

The functioning of the most widely used optical isolators relies on the Faraday magneto-optic effect used in Faraday rotators and the use and generation of polarized light. When a magnetic field is applied to a Faraday rotator, the polarization of the light is rotated, with the generated angle of rotation depending on the strength of the magnetic field and the length of the Faraday rotator as well as the material of the rotator. An Faraday effect optical isolator consists of three parts: a light input polarizer, a Faraday rotator, and a light output polarizer with the input polarizer polarized vertically and the output polarizer polarized to 45 °. Forward propagating light incident on the input polariser is vertically polarized and the subsequent Faraday rotator rotates the polarization of the light by 45 °, as a result of which the light can pass in the forward direction of the isolator. In contrast, light propagating in the reverse direction (reverse direction) is first polarized by the analyzer to 45 °, while the following Faraday polarizer rotates the polarization by 45 °. In this way, horizontally polarized light is generated, which can not penetrate the vertically polarized polarizer in the reverse direction for the most part ( US 7,961,391 B ). The arrangement shown creates an optically unidirectional diode behavior.

Optical isolators based on the Faraday effect have been the subject of numerous inventions (e.g. US 5,808,793 ) DE 699 06 325 T2 2/19/2004, DE 697 29 230 T2 6/23/2005, US 6,462,872 B2 . US 5,917,643 . US 6,208,795 B1 . US Pat. No. 6,480,331 B1 . DE 695 31 716 T2 7/15/2004, DE 695 31 385 T2 4/22/2004, DE 697 14248 T2 . DE 10 2009 016 950 A1 2010.10.14. In addition, publications are also concerned with optical isolators according to the Faraday principle: z. B. L. Feng, M. Ayache, J. Huang, YL. Xu, M.-H. Lu, Y. Fainman, A. Scherer "Nonreciprocal Light Propagation in a Silicon Photonic Chip" Science 5 August 2011, Vo1.333 no. 6043 pp. 729-733 . http://de.wikipedia.org/wiki/Optischer_Isolator ). The Faraday isolators are very complex optical systems - consisting of several polarizers and light rotators - which are too complicated, too expensive for many applications and not or only partially applicable because of their complex structure. The Faraday isolators require electrical and magnetic fields to operate that require special electrodes and make it difficult to use the Faraday isolators. The Faraday isolators are only suitable for polarized light and only for a limited wavelength range.

In the US patent US 7,701,537 B the diode function is taken over by cholesteric liquid crystalline layers with left handed helical structure and wavelengths of selective reflection as well as phase shifter layers. The preparation of the layer systems used is too difficult and hardly practicable for a component to be used and manufactured technically. In the US patent US 5,559,825 are used as optical isolators stack of alternately arranged layers with high and low refractive index as a basis. Due to the non-linear optical behavior of the layers used, the diode behavior of the layer system arises, but only under the action of laser pulses of very high optical powers. The claimed isolator principle is not applicable to commonly available optical powers.

Acousto-optic modulators are sometimes also used as optical isolators ( www.matthiaspospiech.de/files/studien/vortrag ). Their optical isolation effect for laser radiation is based on the frequency or optical wavelength shift of the reflected light in the modulator by twice their modulation frequency when the resulting frequency is outside the laser bandwidth. Acousto-optic modulators must be operated at high frequency and their spatial extent makes them unsuitable for many applications. Furthermore, the frequency or wavelength shift occurring in the acousto-optic modulator is too small in many applications to achieve sufficient optical isolation.

It is an object of the present invention, new optical isolators for optical communication and computer technology, for optical information processing and transmission and for laser technology and optical technologies to provide, compared to the prior art, technical advantages and benefits, are simpler and cheaper to manufacture and operate and eliminate the disadvantages of the prior art. In addition, the new optical isolators should additionally generate laser radiation and realize a spectral conversion of light as well as be suitable for non-polarized light. The new optical isolators are designed to be purely optical and require no operating voltages. They should also be suitable for optical space technology (Free Space Optic) and be used in a wide spectral range. The present invention provides new optical isolators in which a spectral filter and a spectral light converter are optically and mechanically fixedly connected as optical components to form a unitary optical device having optical diode or optical isolator function, wherein the spectral characteristics of the Spectral filter and the spectral light converter are tuned to each other that on the optical isolator according to the invention incident forward light radiation (excitation radiation) with a defined wavelength (eg., Laser) or spectral bandwidth spectrally converted with changed wavelength can pass through the optical isolator, while it is visually absorbed or blocked in the reverse direction. It can already in the manufacturing process of the optical isolator one of the two components z. Example, as thin-film systems are applied to the respective other component and thereby an optical and mechanical connection between the spectral filter and the spectral light converter can be realized or the two optical components are permanently bonded together optically.

The function of the new optical isolator is based on the spectral characteristics of the filter and light converter components used in the invention. Meets according to 1 Light radiation with a predetermined spectral bandwidth in the forward direction 3 on the spectral light converter 2 , So it is absorbed as excitation radiation in the spectral converter and emitted by fluorescence and / or laser effects or other photonic processes spectrally longer wavy (down-conversion) and / or spectrally shorter wavy (up-conversion) as emission radiation. The wavelengths of the spectral light converter 2 incident excitation radiation and the emission radiation emitted by it differ more or less strongly, and in the case of down-conversion their difference as Stokes shift from the material used of the spectral light converter 2 and depends on photonic laser processes (eg halving the wavelength of the emitted radiation by generating the second harmonic). The spectral properties of the spectral filter 1 and the spectral light converter 2 are coordinated so that on the spectral light converter 2 incident excitation radiation due to its wavelength from the spectral filter 1 strongly absorbed or blocked while that of the spectral light converter 2 and in its wavelength of the excitation radiation differing emitted radiation in high transmission the spectral filter 1 and so that the optical isolator can pass. In this way, an optical isolator is created which spectrally converts the excitation radiation with a changed wavelength in the forward direction 3 lets through while in the reverse direction 4 absorbed or blocked. When using the optical isolator according to the invention, depending on the irradiation direction (forward or backward direction), an almost complete transmission or complete absorption or blocking of the excitation radiation and thus a typical diode action in a given spectral range are obtained. By providing a uniform integrated optical component composed of a spectral light converter and a spectral filter, an optical isolator with an optical diode effect is realized, which can be used in a very broad spectral range (from the ultraviolet, visible to the near infrared spectral range) and, surprisingly, very much has good diode properties, works purely optically and requires no operating voltage. By using layer technologies in the production of the optical isolators according to the invention, an optically and mechanically strong bond between the spectral light converter and the spectral filters is possible, and micro-optical arrangements are possible, such as could not previously be realized.

For the spectral separation of excitation and emission radiation steep edge curves between absorption or block and transmission of the spectral filters are required. Due to the strong optical absorption or blocking of the excitation radiation by the spectral filter and the excitation radiation, which is absorbed only incompletely by the spectral light converter is sufficiently absorbed or blocked. Spectral filters which satisfy the requirements of the invention are long-pass, bandpass and short-pass filters which strongly absorb the excitation radiation (optical density 2 to 7, preferably 4) and / or strongly reflect the wavelengths shifted by the spectral converter to high levels Allow transmission (transmission 80 to 98%, preferably 95%). These are z. B. Longpass plastic composite filter from Schott with extreme edge steepness and very good absorption or transmission properties in the absorption and transmission range or absorption filter Blue IF 039 and Green IF 062 {band filter with transmissions between 380 nm and 580 nm) and yellow IF 022, orange IF 041, red 090, dark red IF 091 with edge wavelengths (cut-to wavelength) at 490 nm, 565 nm, 600 nm and 625 nm with good absorption properties and transmissions greater than 90% of Schneider Optische Werke. The filters IF 090 and IF 091 also have a high transmission above 90% (red and black glasses) in the near infrared (NIR) range from 650 nm to 1900 nm, while they absorb in the visible spectral range. The long-pass filters to be used are optically transparent in the longer wavy spectral range above the edge wavelength, while short-pass filters transmit shorter wavy radiation and absorb or block the radiation at an edge wavelength.

Interference and thin film filters are particularly useful when steep edges are required between the block and passband (in the case of small Stokes shifts). Interference filters use the interference effect to reflect and transmit the radiation in certain spectral ranges. The blocking of the radiation takes place here not by absorption but by reflection. Interference filters are characterized by steep spectral curves, high blocking and high transmissions. However, they can be used in the invention only if the radiation reflected by the interference filter does not lead to any disturbing feedbacks in the optical system. When the excitation radiation is generated by lasers, they are generally not applicable. However, if it is necessary for the excitation radiation to be reflected back to the light converter from the spectral filter to increase the efficiency of the spectral conversion of light after incomplete absorption in the spectral light converter, interference filters are well suited as spectral filters.

To produce an optical isolator according to the invention, a polymer solution which is doped with the red perylene fluorescent dye RED-300 is applied in a first variant to a red plastic composite filter (long-pass filter) with an edge wavelength of 600 nm. After evaporation of the solvent obtained as a spectral light converter, a red fluorescent layer which emits after excitation with a green light emitting diode red fluorescent light in the spectral range around 620 nm as emisson radiation. Because of its filtering properties, the red emission radiation can pass the red filter in the forward direction, while the green excitation radiation in the red fluorescent layer is more or less absorbed and blocked in the reverse direction by the red filter. Since the red perylene dye used also acts as a laser dye, the red fluorescent layer also generates laser radiation in the spectral range between 610 nm and 630 nm when used with the second harmonic of a neodymium-yttrium-aluminum-garnet (YAG) laser is excited at 532 nm. The generated red laser radiation passes through the optical isolator in the forward direction while blocking scattered light from the 532 nm excitation radiation in the reverse direction. Perylene-based yellow fluorescence layers with the fluorescent dye yellow 083 serve as spectral light transducers to transform the radiation of a blue light-emitting diode into the yellow spectral range. To realize the corresponding optical isolator one brings according to 2A First, the fluorescent layer of a doped with fluorescent yellow 083 polymer solution on an optical substrate 5 consisting of glass, light-conducting plastic, quartz or another optically transparent material in the spectral range used. After evaporation of the solvent and drying of the layer, the application of a yellow transparent or pigmented colored lacquer acting as a spectral filter takes place 1 which has an optical density of 2 to 6, preferably 4, in the spectral range of the blue light-emitting diode around 470 nm, depending on the layer thickness, and is optically transparent in the spectral range above 490 nm. Should the fluorescent layer 2 act as a light collector for diffused light, the application of acting as a spectral filter yellow color coat takes place 1 according to 2 B on the opposite side of the fluorescent layer of the optical substrate 5 , As a result, impinging blue excitation radiation first strikes the fluorescent layer 2 , is collected there, converted into yellow emission radiation and passed through the optical substrate and the yellow lacquer layer. The optical isolator prepared in this way is arranged so that the excitation radiation of the blue light emitting diode in the forward direction after penetration of the glass substrate first on the yellow fluorescent layer 2 or directly meets them first and there is converted into yellow emission radiation (fluorescence radiation), the high transmission of the layer acting as a spectral filter yellow color coat 1 can happen. In the reverse direction (backward direction) incident blue excitation radiation strikes first on the yellow color coat layer 1 and is completely absorbed there. Depending on the direction of irradiation (forward or backward direction), therefore, the blue excitation radiation is either transmitted or blocked in spectrally converted form by the optical isolator.

Instead of doped polymer layers can also be doped with laser dyes Polymerformkörper- z. B. as a disk-like disk are used as a spectral light converter and instead of the laser dyes based on perylene other fluorescent dyes or laser dyes such. As rhodamines, xanthenes, oxazines, pyromethenes, cuomarins, stilbenes and their mixtures used for the conversion of light and for the generation of laser radiation of different wavelengths. When using the fluorescent dyes in the new optical isolators is their fluorescence yield QY (Quantum Yield), which indicates how much of the absorbed excitation radiation is emitted in a percentage as emission radiation (fluorescence radiation), of importance. Powerful perylene fluorescent dyes and laser dyes achieve a QY between 95% and 100% and allow the excitation radiation to pass spectrally with a changed wavelength at high efficiency and pass the optical isolator. Also very well fluorescent phosphors or phosphors - preferably dispersed in a Polymermatrix- for the production of spectral light converters in Dünnschiehttechnologie with down-conversion are suitable according to the invention. The materials used have the advantage that they also have high photostability as well as high QY (about 90%) even with excitation radiation of high energy and power (high-performance lasers). Use is made here of phosphors based on rare earth metals and doped phosphates, silicates, germanates, oxides, sulfides, oxysulfides, selenides, sulfoselenides, vanadates, niobates, arsenates, tantalates, tungstates, molybdate, halogenates, nitrides, bristles, aluminates, Gallates and halides (eg Litec LLL europium-2 + doped silicates (S440 and FA 539, europium doped yttrium oxides (N78 red / 1N) and cerium and terbium-doped magnesium aluminas (Phosphorus Breitungen) Phosphors produce blue, green and red emission radiation, and in a preferred variant the phosphor materials mentioned are also present as fluorescent nanoparticles Examples are: Al 2: Eu, YVO 4: In, LnPO 4: Ce, Tb and ZnS: Ln, MgF 2: In BaFCL: Sm , MgWO4: Sm, NaGdF4: Yb with Ln = lanthanide, where in the notation used to the right of the colon one or more dopants and to the left of the colon, the host material are listed.

Fluorescent quantum dots (quantum dots, QDs) for producing the spectral light converters can also be used according to the invention. QDs have diameters of less than 100 nm, preferably less than 10 nm. The size distribution of the QDs has an influence on their absorption and fluorescence behavior. It is therefore possible to set the spectral position of the absorption and the fluorescence of the QDs targeted. In particular, the use of QDs permits the overlap of absorption with fluorescence to be minimized and, in this way, to minimize or completely prevent reabsorption losses (inherent absorptions) in the spectral transducers, advantageously for the efficiency of the optical isolator of the present invention. Preferred quantum dots according to the invention are semiconducting materials selected from IAs, InP, GaAs, GaP, GaN, InGaAs, GaInP / InP, CdO, CdSe, CdS, CdSe / CdS, CdTeZnO, ZnS, ZnO, ZnSe, ZnSe, ZnTe, PbS. PbSe, PbTe, HgS, HgSe and HgTe. The quantum dots are also doped: ZnO: M, ZnS: M, ZnSe: M, Cds: M, CdSe: M, where M = Ag, Cu, Al, Mn, Ln. Fluorescent nanoparticles and quantum dots are also very photostable and are characterized by a large Stokes shift with advantage for a good spectral separation between excitation and emission radiation. When using the QDs in the optical isolators according to the invention, polymer nanocomposites are advantageously used for the production technology of the new optical isolators in which the QDs and nanoparticles are dispersed or colloidal in polymer solids, such as polyacrylates, polystyrenes, polyurethanes, semiconducting polymers, sol Gel matrices, Ormoceren and silicates are finely dispersed without aggregate formation. In order to avoid the aggregation impairing the optical properties, the surface of the QDs and nanoparticles must be appropriately functionalized or capped (core-shell structures). For the production of, for example, fluorescent ZnO, ZnS, ZnS: Mn and CdSe / ZnS or CdSe / CdS nanocomposites, the functionalized QDs are dissolved in suitable monomers and the polymer nanocomposites are subsequently produced by polymerization as thin layers or shaped bodies , As polymer matrices, polymethylmethacrylate (PMMA) and other acrylate polymers are particularly suitable. CdSe / ZnS-PMMA nanocomposites have a strong fluorescence radiation at 625 nm after excitation with an argon laser with a wavelength of 488 nm and are very useful as spectral light transducers in the optical isolators according to the invention. Due to their high photostability, fluorescent QDs and nanoparticles as polymer nanocomposites are also very suitable for excitation with ultraviolet radiation (UV). ZnS: Mn and ZnS: Cu nanoparticles in a polymer-acrylate matrix emit strongly as radiation at 590 nm and 490 nm after excitation in the UV in the spectral range from 325 nm to 380 nm as shaped bodies and layers. Yttrium doped with rare-earth ions Vanadium and lanthanum phosphate nanophosphors (REN-X yellow, REN-X red and REN-X green) and SiC nanocrystals as fluorescent polymer nanocomposites show strong UV absorption from 250 nm to 300 nm and show strong emissions in the blue, green / yellow and red spectral range after excitation in the short-wave UV. Polymeric nanocomposites based on CdSe / ZnS in semiconducting polymers are also efficiently UV excitable, e.g. For example, at 376 nm and produce a red fluorescence at 624 nm with a Stokes shift of 248 nm. In this way, absorption and emission bands are strongly spectrally separated, resulting in a very low self-absorption in the spectral transducer material follows. In addition, CdS / ZnS nanocrystals embedded in a silica-sol-gel matrix produce blue laser radiation by excitation with a titanium sapphire laser at 400 nm.

Laser radiation with a wavelength of 532 nm is also well suited as excitation radiation to generate emission radiation in the NIR region (700 nm to 2000 nm), which is important for optical communication. In this application, the spectral light converter used is a barium borate glass doped with neodymium-3 + ions which, after excitation, emits fluorescence emission radiation at 900 nm, 1066 nm and 1330 nm with the strongest emission at 1066 nm. Spectral filters are used for emission radiation in the NIR range, red and black glasses that transmit radiation in the range of 650 nm to 2000 nm in high transmission of more than 90% and strongly block the excitation radiation at 532 nm. Fluorescent erbium-ion nanocrystals in a sol-gel matrix of titanium dioxide and glycidoxypropyltrimethoxysilane in a concentration of 10% by weight and fluorescent PbMo4: Er crystals are also suitable for generating emission radiation in the near infrared spectral range. The polymer nanocomposites and crystals shown show strong emission at 1531 nm and 1550 nm after excitation with an argon ion laser at 488 nm and after excitation at 980 nm.

Since the NIR spectral range of 700 nm to 2000 nm is particularly important for optical communication, a spectral conversion of light from NIR in the visible (up-conversion) or even within the NIR range for the insulator according to the invention is very interesting from a technical point of view. Short-range filters which absorb the long-wave spectral component in the NIR and are optically transparent for the visible spectrum or for shorter wavy components of the NIR serve as spectral filters. To realize an optical isolator in said spectral range are optically non-linear crystals, z. B. for generating the second harmonic or sum and difference frequencies suitable. When the optically nonlinear crystal KTP (potassium titanyl phosphate) is excited with a neodymium-YAG laser at 1064 nm, the emission radiation is green laser radiation at 532 nm as second harmonic, which is transmitted by the short-pass filter, while the excitation radiation is strongly absorbed at 1064 nm , In the production of the optical isolator, the optically non-linear crystal is applied to the corresponding short-pass filter with an optical adhesive, wherein the in 2C shown geometry of an optical isolator is favorable in this application, because the optically non-linear crystal is surrounded as a spectral light converter from the spectral filter. In the 2C The illustrated geometry is also applicable to diode pumped solid state lasers (DPSS) efficiently. The laser crystal used in DPSS lasers serves as a spectral light converter. If you stir z. As a neodymium-YAG laser with emitting at 808 nm and 888 nm laser diodes, one obtains laser emission radiation at 1064 nm. As a spectral filter is used in this application, black filter, the excitation radiation at 808 nm and 888 nm strongly absorb and emit the emission radiation at 1064 nm to a high degree. According to the invention, up-converter materials which, as a result of photonic processes, convert excitation radiation in the NIR range into shorter-wave emission radiation, are also very advantageous. Very suitable here are rare-earth based phosphors such. Sodium yttrium-4-fluoride doped with 20% erbium-3 + ions (NaYF4: 20% Er3 +) and other rare earth ions. The present as a powder materials are applied to produce the optical isolator of the invention in a polymer binder as a layer on the short-pass filter. Irradiation of the transducer layers with 1523 nm or in the spectral range 1300 nm to 1700 nm gives emission radiation at 980 nm, 810 nm, 660 nm, and 550 nm. Green emission radiation at 550 nm and 526 nm is also obtained on PbMa4: Er crystals and BaTiO3: Er sol gel powders after irradiation at 980 nm and 816 nm and 973 nm. The emission radiation thus generated covers a broad spectral range. If the phosphors to be used are used as nanoparticles, a spectral conversion of 974 nm into blue, green and red emission radiation is possible. Other efficient up-converter materials include erbium-, yttrium-, and neodymium-doped nanocomposites of SiO 2 -titanium dioxide sol-gel layers. The conversion process can be observed under an 808 nm laser diode and produces green (526 nm) and red (650 nm) emissions. Also available as nanoparticles zinc sulfide phosphors, doped with manganese, europium and copper ions allow a spectral conversion of 795 nm in the visible spectral range. Infrared excitable phosphors based on rare earth oxysulfide generate emission radiation at 660 nm and 550 nm after excitation at 980 nm or after excitation in the spectral range between 1500 nm and 1600 nm. Erbium- and yttrium-doped nanocomposites based on transparent nanocrystals of SiO2: PbF2 also show usable up-conversion properties in optical isolators (from 980 nm in the visible spectral range).

The optical isolators of the invention have great technical advantages over the prior art, are inexpensive and easy to manufacture and have a large technical scope. They also work with non-polarized light, do not require operating voltages and can be used from the ultraviolet to visible spectral range as well as in the near-infrared range important for optical communication. They work purely optically and therefore require little space when used. Due to the possible thin-film technology in their manufacture, the optical isolators according to the invention are suitable for both Large-area applications as well as in micro-optics and optical fiber technology can be used. They are very well suited for the optical free space technique (FSO). Compared to the acousto-optic isolators, they have a much greater wavelength shift between excitation and emission radiation with advantage in the spectral separation of these radiations.

The optical isolators according to the invention allow, in addition to their diode function, to simultaneously generate laser radiation and to perform a spectral conversion of light.

embodiment

To produce a large-area optical isolator for radiation with a lamp consisting of blue light-emitting diodes, a yellow fluorescent layer is initially applied to an optical substrate made of non-ferrous silicate glass, light-conducting plastic or quartz glass with dimensions of 100 mm by 100 mm. The fluorescent layer is prepared by dissolving the yellow fluorescent dye yellow 083 in a polymer solution consisting of 15% ethyl methacrylate copolymer (Paraloid 72) dissolved in ethyl acetate or methoxypropanol, with a maximum of one gram of yellow 083 per liter of solution. The polymer solution doped with fluorescence yellow is applied to the optical substrates by means of a spraying or casting technique or also with coating, and the solvent is evaporated at 50 ° C. and the layers are dried. This results in a yellow fluorescent layer acting as a spectral light converter in the thickness range between 50 microns and 200 microns on the optical substrate in this way. As the spectral filter, a yellow color coat highly absorbing in the blue spectral range with an optical density of 4 to 6 is selected depending on the thickness of the yellow color coat and brings this gel black onto the surface of the optical substrate opposite the yellow fluorescent layer. In this way, a large-area optical isolator is formed, which consists of a yellow fluorescent layer, an optical substrate and a yellow color coat layer. If, in this arrangement, the radiation of the blue light emitting diodes in the forward direction first meets the yellow fluorescent layer, the blue radiation is efficiently transformed into yellow light and, after penetrating the optical substrate, the yellow color coat layer acting as a spectral filter can pass, because the yellow colored yellow light is optically transparent. Blue light-emitting diode radiation, which first hits the yellow color coat layer in the backward direction, is completely absorbed due to the absorption behavior of the yellow color coat. The yellow color coat layer acts on the blue radiation like a black wall, while blue radiation of changed wavelength striking the fluorescence layer first penetrates the insulator arrangement in high transmission. The illustrated optical isolator acts as an optical diode which transmits blue radiation of changed wavelength in the forward direction, while the blue radiation is completely absorbed in the reverse direction.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 7961391 B [0003]
• US 5808793 [0004]
• DE 69906325 T2 [0004]
• DE 69729230 T2 [0004]
• US 6462872 B2 [0004]
• US 5917643 [0004]
• US 6208795 B1 [0004]
• US 6480331 B1 [0004]
• DE 69531716 T2 [0004]
• DE 69531385 T2 [0004]
• DE 69714248 T2 [0004]
• DE 102009016950 A1 [0004]
• US 7701537 B [0005]
• US 5559825 [0005]

Cited non-patent literature

• L. Feng, M. Ayache, J. Huang, YL. Xu, M.-H. Lu, Y. Fainman, A. Scherer "Nonreciprocal Light Propagation in a Silicon Photonic Chip" Science 5 August 2011, Vo1.333 no. 6043 pp. 729-733 [0004]
• http://en.wikipedia.org/wiki/Optical_Isolator [0004]
• www.matthiaspospiech.de/files/studien/vortrag [0006]

Claims (8)

Optical isolator with spectral conversion of light and generation of laser radiation, comprising a spatially unit forming spectral light converter, spectral filters and an optical substrate with optical diode function, wherein incident on the spectral light transducer radiation from UV to the near infrared spectral region spectrally longer wavelength (down-conversion ) and / or spectrally shorter wavy (up-conversion) is emitted as isotropic or laser radiation and optically passes the optical isolator in the forward direction and completely absorbed or blocked in the reverse direction. Optical isolator according to claim 1, characterized in that the spectral light converter is composed of fluorescent dyes, laser dyes, nanoparticles, quantum dots and phosphors and phosphors. Optical isolator according to Claims 1 and 2, characterized in that the spectral filters consist of plastic composite filters, color filters, black and red glasses and interference filters as longpass, shortpass and bandpass filters. Optical isolator according to claim 1 to 3, characterized in that it spectrally converts incident radiation and generates laser radiation, does not require polarized radiation and is suitable for diffused light of low intensity and laser radiation with high intensity and manages operating voltage. Optical isolator according to claim 1 to 4, characterized in that rare earths are contained in the spectral light converter and the spectral light converter is composed of optically non-linear and fluorescent and laser crystals. Optical isolator according to Claims 1 to 5, characterized in that the rare earths, phosphors, nanoparticles, quantum dots and phosphors contained in the spectral light converter are present as layers and shaped bodies in polymers and as polymeric nanocomposites and dispersed in ormocers, sol-gel matrices and in silicates are. Optical isolator according to claim 1 to 6, characterized in that it is used for the optical isolation of radiation in optical communications and computer technology, in optical information processing and information transmission, in the optical free space technology (FSO technology) as well as in other optical technologies and in the laser - and measurement technology is used. Optical isolator according to claim 1 to 7, characterized in that it can be used in the spectral range from 250 nm to 2000 nm.

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