Abstract: The present application relates to a method and system for characterization and compression of ultrashort pulses. It is described a flexible self-calibrating dispersion-scan technique and respective system to characterize and compress ultrashort laser pulses over a broad range of pulse parameters, where previous knowledge of the amount of dispersion introduced for each position or step of the compressor is not required. The self-calibrating d-scan operation is based on the numerical retrieval of the spectral phase of the pulses using an optimization algorithm, where the spectral phase is treated as a multi-parameter unknown variable, and where the unknown dispersion of the dispersion scanning system is described by a theoretical model of its functional dependence on the compressor position.

Abstract: Exposure to a static magnetic field changes the fluorescence intensity of a wide range of fluorophores, including small molecules (e.g., tryptophan), complex organizations of fluorophores (e.g., proteins), quantum dots, nanoparticles, and other materials. Different materials may experience different changes in fluorescence emission upon exposure to a magnetic field—for instance, some or all of a material's fluorescence emission spectrum may increase in amplitude or shift in wavelength. Different materials may also experience different changes in relaxation time, which is the time constant associated with fluorescence decay. These magnetically induced differences fluorescence emission spectra and decay can be used to identify, classify, or sort materials noninvasively.

Abstract: Systems for switching optical signals are disclosed. Such a system may include a splitter and a plurality of polarizing filters. The splitter may be configured to receive emitted light and duplicate the emitted light into a plurality of light copies. Each polarizing filter may have a polarization and may be operably connected to the splitter. In addition, each polarizing filter may be configured to receive at least one of the plurality of light copies, filter the at least one of the plurality of received light copies such that light having a similar polarization as that of the polarizing filter passes through the polarizing filter, and output one of a plurality of outputs.

Abstract: An input/output port, a birefringent element, variable polarization rotator, and a reflector are arranged along an optical axis in the order named. The variable polarization rotator includes permanent magnets for applying a fixed magnetic field to a Faraday rotator in an in-plane direction to magnetically saturate the Faraday rotator and a solenoid coil for applying a variable magnetic field to the Faraday rotator in a direction of the optical axis. A fixed magnetic field is applied in the <211> direction, in which the Faraday rotator is likely to be magnetically saturated. The Faraday rotator can be saturated with a low magnetic field of about 100 Oe. The permanent magnets may employ ferrite permanent magnets, which have weak magnetic forces. A variable magnetic field may also be reduced. Therefore, an air-core coil can be used.

Abstract: An input/output port, a birefringent element, variable polarization rotator, and a reflector are arranged along an optical axis in the order named. The variable polarization rotator includes permanent magnets for applying a fixed magnetic field to a Faraday rotator in an in-plane direction to magnetically saturate the Faraday rotator and a solenoid coil for applying a variable magnetic field to the Faraday rotator in a direction of the optical axis. A fixed magnetic field is applied in the <211> direction, in which the Faraday rotator is likely to be magnetically saturated. The Faraday rotator can be saturated with a low magnetic field of about 100 Oe. The permanent magnets may employ ferrite permanent magnets, which have weak magnetic forces. A variable magnetic field may also be reduced. Therefore, an air-core coil can be used.

Abstract: An apparatus to modify an incident free space electromagnetic wave includes a block of an artificially structured material having an adjustable spatial distribution of electromagnetic parameters (e.g., ?, ?, ?, ?, and n). A controller applies control signals to dynamically adjust the spatial distribution of electromagnetic parameters in the material to introduce a time-varying path delay d(t) in the modified electromagnetic wave relative to the incident electromagnetic wave.

Abstract: The device includes two supports and a primary conductive strip. The primary conductive strip includes a neutral surface, a first side, and a second side. The primary conductive strip is connected one of directly and indirectly on the first side to the two supports such that the primary conductive strip is constrained in two dimensions and movable in one dimension. The device also includes a primary distributed feedback fiber laser. The primary distributed feedback fiber laser includes a fiber axis. The primary distributed feedback fiber laser is connected to the primary conductive strip along one of the first side and the second side such that there is a positive distance between the neutral surface of the primary conductive strip and the fiber axis of the primary distributed feedback fiber laser.

Abstract: An optical module is configured with a combination of a single-mode oscillating light source and an optical filter. In this optical module, the single-mode oscillating light source outputs a single-mode, frequency-modulated signal. Further, the optical filter converts the frequency modulation to an amplitude modulation. And, the single-mode oscillating light source and the optical filter are packaged without active alignment on the same substrate. Accordingly, it is possible to realize an optical module in a simple and low-cost configuration by packaging the single-mode oscillating light source and the optical filter by passive alignment, without active alignment, on the same substrate, and by using a simple optical filter such as a waveguide ring resonator, which converts a frequency modulation to an amplitude modulation.

Abstract: An adaptive optics system is provided. The system includes a light source, a pair of deformable mirrors and a detection module. The light source is configured to provide an outgoing beam. The outgoing beam has an amplitude and a phase. The first deformable mirror is configured to reflect the outgoing beam and adjust its associated amplitude. The second deformable mirror is configured to reflect the outgoing beam reflected from the first deformable mirror and adjust its associated phase. The detection module is configured to detect an incoming beam and the reflected outgoing beam from the second deformable mirror and generate certain signals. The signals are used to control the first and second deformable mirrors such that the amplitude of the outgoing beam is the same as that of the incoming beam and the phase of the outgoing beam is opposite that of the incoming beam.

Abstract: The integrated magneto-optical modulator with optical isolator of the present invention comprises an optical isolator unit, a magneto-optical modulator unit, an impedance adjuster. The optical isolator unit rotates a polarization of an incident light from a light source to transmit the light with rotated polarization, and eliminates a reflected feedback light toward the light source. The magneto-optical modulator unit modulates an intensity of the light from the optical isolator unit and transmitting the modulated light outside. The impedance adjuster adjusts electrical impedance at the magneto-optical modulator unit in order to effectively introduce the high-frequency signal for light modulation to the magneto-optical modulator unit. Further, the optical isolator unit and the magneto-optical modulator unit are contained a single package.

Abstract: The invention relates to an optical signal transmission system with phase modulation and the implementation method. The system adds a phase modulator in the optical signal-emitting module. The optical pulses after intensity modulation and a high-speed data stream are input to the phase modulator synchronously, where the optical pulses are modulated in phase according to the high-speed data stream into high-speed optical signals with chattering. According to the invention, the phase modulator added in the optical signal-emitting module modulates optical signals in phase, which has been modulated in intensity. Appropriate chattering modulation can depress effectively the non-linear effect in the transmission of optical pulses through the interaction between chromatic dispersion and non-linear effects. Thus, the power input of individual channels is increased effectively, and the passive relay regeneration distance is extended.

Abstract: A liquid phase epitaxy method is used to grow the Faraday rotator with a small saturation field (Hs). The Faraday rotator has the formula: Bi3−x−y−zGdxTbyMzFe5−w−nGawPnO12, where M is selected from Y, Yb, Lu, and P is selected from Al, Si, Ge. X, y, w and n are chosen from the ranges of 0.5≦x≦1.0, 0.5≦y≦1.0, 0.2≦z≦0.5, 1.5≦x+y+z≦2.0, 0.5≦w≦1.0, 0.15≦n≦0.5, 0.8≦w+n≦1.2. Without M and P, a Type-L Faraday rotator with a linear BH curve is provided, which is well suited for variable optical attenuators. With M and P, a Type-R Faraday rotator with a rectangular hysteresis loop is provided, which is well suited for optical switches. Both are also well suited for use in optical isolators and circulators.

Abstract: A method of manufacturing is used to manufacture a magnet-free Faraday rotator having a square hysteresis loop, the Faraday rotator being formed of a bismuth-substituted rare earth iron garnet single crystal that has a compensation temperature in the range of 10 to 40° C. and is grown on a non-magnetic garnet substrate by a liquid phase epitaxy. The method comprising the steps of placing the bismuth-substituted rare earth iron garnet single crystal film in an environment of a temperature at least 20° C. away from the compensation temperature; and applying an external magnetic field higher than 1000 Oe to the bismuth-substituted rare earth iron garnet single crystal film so that the bismuth-substituted rare earth iron garnet single crystal film is magnetized to have a square hysteresis loop.

Abstract: An optical isolator comprsing at least two parts of a Faraday rotator obtained from a garnet crystal and an analyzer, which is small in size, can be mounted directly to a semiconductor laser. The garnet crystal is grown, by a liquid-phase epitaxial growth technique, on the substrate of a garnet with a lattice constant of 12.514±0.015 Å, and consists of the following composition formula: (Tb1−(a+b+c+d)LnaBibM1cEud)3(Fe1−eM2e)5O12 where Ln is an element selected from rare-earth elements excluding Tb and Eu, and Y; M1 is an element selected from elements Ca, Mg, and Sr; M2 is an element selected from elements of Al, Ga, Sc, In, Ti, Si, and Ge; a, b, c, d, and e are defined as 0≦a≦0.5, 0.3<b≦0.6, 0≦c≦0.02, 0<d≦0.3, and 0.01<e≦0.3, respectively.

Abstract: An optical modulator includes a magnetic ferrite single crystal, an optical source, a photoreceptor system and an analyzer. The magnetic ferrite single crystal has a transducer mounted and arranged to receive a microwave. The microwave is modulated by a signal having a frequency lower than the microwave. Light emitted from the optical source is introduced to the magnetic garnet single crystal and modulated by the microwave applied to the transducer. The photoreceptor system receives the modulated light that is emitted from the magnetic ferrite single crystal. The analyzer is provided between the magnetic ferrite single crystal and the photoreceptor system, and the analyzer is arranged such that a rotation angle of the analyzer about an optical axis thereof is shifted by an angle in the range of about 40 degrees to about 50 degrees from an extinct position at which an amount of direct-current light transmitted through analyzer is minimized.

Abstract: A low-rate data transmission system and method are disclosed that use the Faraday effect to modulate the polarization state of light traveling in an optical fiber. The resulting change in polarization is used to communicate information over the fiber. The low-rate data transmission system includes a low-rate signal source producing current in a wire coil wrapped around an optical fiber. Information is conveyed in accordance with the present invention by the selectively introducing a polarization change into the light carried by the fiber. Generally, the source light at the input of the optical fiber can be randomly polarized and information is conveyed in accordance with the present invention by the presence or absence of a predefined polarization introduced into the light. The longitudinal magnetic field produced by a current in the coil rotates the plane of polarization of the light, in accordance with the well-known Faraday effect.

Abstract: An object is to provide a magnetic garnet material, even if a thickness of an element is made thin, in which a sufficient Faraday rotation capacity can be obtained, a magnetic field for saturation can be controlled to be less than 200 (Oe), and a magnetic compensation temperature can be controlled to be less than 0° C. as well as to provide a Faraday rotator which can be made thin, suppresses a manufacturing cost and achieves a high yielding. The above object can be achieved by a magnetic garnet material known as the general chemical formula BixYbyGdzM13-x-y-zFewM2uM35-w-uO12 and the Faraday rotator using the above material. However, M1 is more than one kind of chemical elements which can replace Bi, Yb or Gd, M2 is more than one kind of non-magnetic chemical elements which can replace Fe, and M3 is more than one kind of chemical elements which can replace Fe and M2. Further, x, y, z, w and u respectively satisfies 1.0≦x≦1.6, 0.3≦y≦0.7, 0.9≦z≦1.6, 4.0≦w≦4.3 and 0.7≦u≦1.0.

Abstract: A specific polarized light component out of a light wave passed through a magneto-optic crystal (for example YIG) is extracted by a polarizer. The intensity of the light beam output from the polarizer depends on strength and direction of magnetic fields applied to the magneto-optic crystal. The magneto-optic crystal is applied with a first and a second magnetic field acting in directions different from each other and the strength of the composite magnetic field of them is set to exceed a predetermined value at all times. By varying at least one of the first and second magnetic fields, the attenuation factor in the magneto-optic crystal can be changed continuously and with good reproducibility.

Abstract: Methods and apparatus for isolating a modulation region of an external modulator that has a semiconductor waveguide structure that comprises at least one integral isolation region.

Abstract: The present invention provides an optical device making use of a magneto-optical effect. The optical device comprises: a reflector for reflecting an input beam as a reflected beam; a magneto-optical crystal provided so as to pass the input and reflected beams; a first unit for applying a magnetic field to the magneto-optical crystal; and a second unit for varying the magnetic field in accordance with a control signal. The configuration described above allows a small magneto-optical crystal to be used and, thus, a small-size and a low-cost Faraday rotator to be provided. By adding a polarizer to such a Faraday rotator, a variable optical attenuator can be obtained. In particular, by employing a wedge plate as the polarizer, a polarized-independent optical attenuator can be provided.

Abstract: A specific polarized light component out of a light wave passed through a magneto-optic crystal (for example YIG) is extracted by a polarizer. The intensity of the light beam output from the polarizer depends on strength and direction of magnetic fields applied to the magneto-optic crystal. The magneto-optic crystal is applied with a first and a second magnetic field acting in directions different from each other and the strength of the composite magnetic field of them is set to exceed a predetermined value at all times. By varying at least one of the first and second magnetic fields, the attenuation factor in the magneto-optic crystal can be changed continuously and with good reproducibility.

Abstract: An optical device which can be used as a Faraday rotator which can provide an arbitrary Faraday rotation angle in accordance with a positional condition. The optical device includes first and second ports, magneto-optical crystal, and a unit for applying a magnetic field to the magneto-optical crystal. The first port is positioned in a first region while the second port is positioned in a second region. The first and second ports are optically coupled by a light beam. The magneto-optical crystal is provided such that the light beam may pass therethrough. The unit for applying applies a magnetic field to the magneto-optical crystal so that magnetization of the magneto-optical crystal may have a given distribution in a plane substantially perpendicular to the light beam.

Abstract: An apparatus for, and method of, decreasing a temporal duration of an optical input pulse having an input power spectrum associated therewith, the apparatus and method operative on at least unchirped optical input pulses. The apparatus comprises: (1) a zero-dispersion pulse shaper for receiving the optical input pulse and spectrally spreading the input pulse to produce a spectrally-spread pulse and (2) a modulator array interposed within the zero-dispersion pulse shaper for receiving the spectrally-spread pulse and selectively attenuating a portion of the power spectrum of the spectrally-spread pulse by a predetermined amount to produce a selectively-attenuated spectrally-spread pulse, the zero-dispersion pulse shaper focusing and recombining the selectively-attenuated spectrally-spread pulse to produce an output pulse having a broader power spectrum than the input pulse, the output pulse further having a temporal duration less than the input pulse, regardless of whether the input pulse is chirped.

Abstract: A polarization plane switch comprising a Faraday rotator made of an iron-containing garnet single-crystal film and magnetic field applying devices capable of reversing a magnetic field to be applied to the Faraday rotator. The polarization plane switch has a structure in which magnetization of part of the Faraday rotator is unsaturated and that of the remaining portion of it is saturated when a magnetic field is applied to the Faraday rotator by the magnetic field applying device, and a light beam passes through the magnetically saturated portion almost vertically to the film surface. As the above Faraday rotator, it is the most preferable to use a Faraday rotator made of Bi-substituted iron garnet single crystal formed by liquid-phase epitaxy and having a compensation temperature, and thermally treated under the top condition at a temperature between 1,120.degree. and 1,180.degree. C. for 7 hours or less.

Abstract: A reflection type magnetooptic sensor head is disclosed. The respective structural elements are aligned following a light source in the order of a light inputting/outputting path, polarizer, Faraday rotator, and reflecting mirror. The Faraday rotator is made of a (111) bismuth-substituted iron garnet single crystal film having [111] axis at an angle of 5-60 degrees with an axis normal to the film surface. The reflecting mirror is positioned such that a light incident upon the reflecting mirror is substantially normal to the surface of the reflecting mirror.

Abstract: Apparatus, and a corresponding method for it use, for directly modulating an optical carrier with a radio-frequency (rf) electrical signal. A semiconductor electroabsorptive modulator is operated at an optical wavelength and electrical bias voltage carefully selected to provide a near-linear electrical-to-optical transfer characteristic and to keep rf insertion loss low. Further reduction of insertion loss is achieved by use of an extremely short device, or a single quantum well device configuration, or both. Linearity is further optimized by choosing an appropriate combination of optical polarization mode, optical reflectivity of the device facets, and the number and physical properties of multiple quantum wells.

Abstract: An optical filter device comprised of two parallel arrays of lenses. Each lens in the first array faces a lens in the second array to form a pixel. Lens pairs in a pixel are separated by the sum of their focal distances and include in their common focal surface a "smart" layer for modulating light passing through the focal surface. Preferred embodiments include car rear view mirrors, sunglasses, glasses for night driving, laser goggles, nuclear goggles, sun visors, sun shields, windshields, space suit helmet visors, optical instrument protection devices, window filters and energy conservation devices.

Abstract: An optical system in which optical circulators with polarization plates are used for light modulation of plane polarized light waves. The light modulation is used for black and white printing, grey scale printing and for adjustment of beam intensity of plane polarized light waves.

Abstract: A reflective mode, magneto-optic spatial light modulator (MOSLM) device has planar electrical conductors which function both as optical mirror surfaces and as the address conductors for random access, selective switching of an associated individual pixel element which is formed from a magneto-optic material that exhibits magnetic domain characteristics, and further has a crossover portion of one of the reflective electrical conductors embedded in the magneto-optic device material at a nucleation region formed in the device material.

Abstract: A reflective mode, magneto-optic spatial light modulator (MOSLM) device has one or more pixel elements formed from a selected magneto-optic material with a respective pair of coincident current select electrical conductors associated with each pixel where at least one of the conductors is planar and thereby develops a reflector surface that reflects incident radiation, such as polarized light of an optical beam, which has passed at least through an associated pixel back through the magneto-optic material and resident single magnetic domain of the pixel.