Abstract: An optical modulator module is disclosed, comprising a bendable flexible printed circuit board in which a circuit pattern is formed, and to which control signals are inputted from the outside; an optical modulator element modulating an incident light according to a driving voltage and sending out the modulated light; an at least partially transparent substrate through which the incident light and the modulated light pass, and in which a circuit pattern is formed; and a driving integrated circuit electrically connected with the flexible printed circuit board, and supplying the optical modulator element with the driving voltage according to the inputted control signals, the flexible printed circuit board being electrically connected with the substrate.

Abstract: Plasmons on a waveguide may deliver energy to photocatalyze a reaction. The waveguide or other energy carrier may be configured to carry electromagnetic energy and generate plasmon energy at one or more locations proximate to the waveguide, where the plasmon energy may react chemically with a medium or interaction material.

Abstract: A backside light unit employs a light valve having an array of individually addressable pixels for illuminating direct view imaging panels.

Abstract: An apparatus, including a substrate, having an internal surface where at least a portion of the internal surface has a smoothly varying curvature in three orthogonal directions. The apparatus also includes a photonic crystal disposed over and conformal to at least a portion of the internal surface having the smoothly varying curvature.

Abstract: A new reconfigurable cascadable all-optical on-chip device is presented. The gate operates by combining the Vernier effect with a novel effect, the gain-index lever, to help shift the dominant lasing mode from a mode where the laser light is output at one facet to a mode where it is output at the other facet. Since the laser remains above threshold, the speed of the gate for logic operations as well as for reprogramming the function of the gate is primarily limited to the small signal optical modulation speed of the laser, which can be on the order of up to about tens of GHz. The gate can be rapidly and repeatedly reprogrammed to perform any of the basic digital logic operations by using an appropriate analog optical or electrical signal at the gate selection port. Other all-optical functionality includes wavelength conversion, signal duplication, threshold switching, analog to digital conversion, digital to analog conversion, signal routing, and environment sensing.

Abstract: A wireless PC card includes a housing portion including a width and a lens extending substantially the width of the housing portion; a light pipe housed by the housing portion; a substantially flat plug portion extending from the housing portion and configured to be received by a socket of a portable computer for communicating the PC card with the portable computer; an antenna for sending and receiving a wireless signal connected to the housing portion; and a circuit board including an illumination device and electronics to cause the illumination device to emit flashing illumination, causing the lens to emit flashing illumination via the light pipe while the PC card searches for a wireless signal and emit steady state illumination, causing the lens to emit steady state illumination via the light pipe while the PC card maintains a sufficient wireless signal connection.

Abstract: A broadband optical spectrum generating apparatus 20 includes a ultrashort pulsed fiber laser 22 that generates pulsed light having a pulse width in the unit of picosecond to femtosecond, and broadband optical spectrum-generating optical fibers 24 that are connected with the ultrashort pulse fiber laser 22 via a lens 26 and have characteristics of normal dispersion, that is, a nonlinear coefficient of not less than 10 [W?1km?1] and a magnitude of wavelength dispersion of not greater than a value 0 [ps/km/nm] with regard to a wavelength of the pulsed light. The resulting output is super continuum that is widely broadened to a wavelength band of 1400 nm to 1750 nm and is chirped to a linear characteristic.

Abstract: A display device comprising the following arranged from light input side in the order listed below: a first reflector having a semi-transmissive and semi-reflective property; a translucent porous body having a plurality of pores in which a translucent material is filled, each of the pores having a substantially smaller diameter than the wavelength of input light; and a second reflector having a perfect reflection property, or a semi-transmissive and semi-reflective property. The average complex refractive index of the translucent porous body is changeable with respect to each display dot, and the wavelength of light absorbed by the translucent porous body is changeable with respect to each display dot according to the average complex refractive index. In this way, the input light is modulatable, and the modulated light is outputted from the first reflector and/or the second reflector to perform image display.

Abstract: A micro-louver (1) includes: a transparent substrate (2); a concavoconvex shape portion (5) formed on at least one surface of the transparent substrate (2) and in a prescribed pattern for diffracting incident light to form an image; and a light controlling layer (7) including at least one transparent layer (3) and at least light-absorption layer (4) arranged alternately on said at least one surface of the transparent substrate (2), each of said at least one transparent layer (3) and said at least one transparent layer (4) extending in a direction that intersects said at least one surface of the transparent substrate (2).

Abstract: Plasmons on a waveguide may deliver energy to photocatalyze a reaction. The waveguide or other energy carrier may be configured to carry electromagnetic energy and generate plasmon energy at one or more locations proximate to the waveguide, where the plasmon energy may react chemically with a medium or interaction material.

Abstract: Methods and apparatus are described for modulating an optical signal using electroabsorption in conjunction with an optical interferometer. Phase-shift keying modulation can be achieved with lower amplitude modulator drive signals than conventional methods by splitting the signal to be modulated into multiple optical modes and interferometrically combining the modes after modulating at least one of the modes with an EAM. Using the present invention, the extinction ratio performance of ASK can be significantly improved for a given drive voltage or a desired extinction ratio can be achieved with a substantially lower drive voltage. Hence, the elecro-optic bandwidth of EAMs can be enhanced by overcoming the trade-off relationship between extinction ratio and bandwidth. Furthermore, the present invention can be used to generate other modulation formats, such as QPSK or QAM, with much lower drive voltages, thereby reducing the cost and power consumption of the high-speed drive electronics for the modulation.

Abstract: A light source device includes: a plurality of light emitting elements that emit laser light; and a wavelength selective element that includes a light selective region functioning as a resonator mirror of the light emitting element by selecting light of predetermined selective wavelength from the laser light emitted from one of the light emitting elements and reflecting the selected light toward the light emitting element while allowing the remaining laser light to pass therethrough, and a base member having a plurality of the light selective regions so that the wavelengths of the light selected by the light selective regions are different from each other.

Abstract: An optical RZ transmitter comprises an optical signal source and a pair of electro-optical modulators in tandem, one arranged to receive a NRZ electrical data signal and the other a clock signal at the data rate of the data signal. The phase difference between the data signal and the clock signal is controlled by adding a first dither signal to a bias signal applied to the modulator receiving the data signal, and a second dither signal, having a different frequency, to the phase difference. The amplitude of variations in the power of the optical output signal corresponding to cross-modulation of the first and second dither signals is detected and the phase difference is controlled in response to the detected amplitude.

Abstract: Plasmons on a waveguide may deliver energy to photocatalyze a reaction. The waveguide or other energy carrier may be configured to carry electromagnetic energy and generate plasmon energy at one or more locations proximate to the waveguide, where the plasmon energy may react chemically with a medium or interaction material.

Abstract: The present invention is directed to a novel arrangement of optical devices for the rapid patterning of laser profiles used for desorption and/or ionization sources in analytical mass spectrometry. Specifically, the new optical arrangement provides for a user-defined laser pattern at the sample target that can be quickly changed (on a microsecond timescale) to different dimensions (or shapes) for subsequent laser firings.

Abstract: Techniques for analog processing of high time-bandwidth-product (TBP) signals use a material with an inhomogeneously broadened absorption spectrum including multiple homogeneously broadened absorption lines. A first set of signals on optical carriers interact in the material during a time on the order of a phase coherence time of the homogeneously broadened absorption lines to record an analog interaction absorption spectrum. Within a time on the order of a population recovery time for a population of optical absorbers it the material, the interaction absorption spectrum in the material is read to produce a digital readout signal. The readout signal represents a temporal map of the interaction absorption spectrum, and includes frequency components that relate to a processing result of processing the first set of signals. The techniques allow processing of RADAR signals for improved range resolution to a target, as well as speed of the target, among other uses.

Abstract: A semiconductor optical modulation device includes a semiconductor optical modulator, an input terminal which is connected to a drive circuit for supplying an electrical signal to the semiconductor optical modulator, an output terminal which is connected to a terminating resistor, an input wire which connects the input terminal to an electrode of the semiconductor optical modulator, and an output wire which connects the output terminal to the electrode of the semiconductor optical modulator. In addition, an additional capacitor or an additional resistor is disposed between the input terminal and the output terminal, and connected in parallel with a series circuit including the input wire and the output wire.

Abstract: An iono-refractive structure that includes one or more ion insertion layers having a real portion and an imaginary portion of the dielectric constant is provided. While both the real portion and the imaginary portion of the dielectric constant change, the change in the imaginary portion is less than the change in the real portion at the wavelength of interest or at the operational wavelength. The iono-refractive structure may be suitable for the fabrication of or integration with tunable optical filters, wavelength-selective optical elements, active modulated interferometers, optical phase shifters, optical phased array beam steering, optical phased array beam tracking, tunable optical filters, sensors, variable lenses, tunable diffraction gratings, and other optical components.

Abstract: An electro-absorption light intensity modulator device is provided that comprises a first and a second layer disposed relative to the first layer so as to provide a light-absorbing optical confinement region. The first layer comprises a first insulator layer, and the light-absorbing optical confinement region comprises at least one quantum-confined structure. The at least one quantum-confined structure possesses dimensions such, that upon an application of an electric field in the at least one quantum-confined structure, light absorption is at least partially due to a transition of at least one carrier between a valence state and a conduction state of the at least one quantum-confined structure. A method is also provided for fabricating an electro-absorption light intensity modulator device.

Abstract: An optical modulator comprises a first waveguide layer and a barrier layer, and a quantum well layer sandwiched between the first waveguide layer and the barrier layer, where the quantum well layer has a graded composition that varies the bandgap energy of the quantum well layer between a minimum bandgap energy and the bandgap energy of at least one of the first waveguide layer and the barrier layer.

Abstract: The invention relates to a variable optical attenuator constructed as a Mach Zehnder planar lightwave circuit, particularly including a channel waveguide support structure for heat isolation and stress relief to reduce polarization dependent loss (PDL) and power consumption in the device. Power reduction trenches comprise longitudinal segments having small stress relief pillars of cladding material left in between them in the etching process. The waveguides of the MZI are supported by a main pillar structure and integral stress relief pillars which remain after removal of the trenches. The waveguide is surrounded by air on three sides for improved heat isolation. The performance of the present invention shows substantial improvement in PDL and extinction ratio over the prior art continuous trench design, and also, to a smaller degree, over the case where power reduction trenches are not used at all.

Abstract: An iono-refractive structure that includes one or more ion insertion layers having a real portion and an imaginary portion of the dielectric constant is provided. While both the real portion and the imaginary portion of the dielectric constant change, the change in the imaginary portion is less than the change in the real portion at the wavelength of interest or at the operational wavelength. The iono-refractive structure may be suitable for the fabrication of or integration with tunable optical filters, wavelength-selective optical elements, active modulated interferometers, optical phase shifters, optical phased array beam steering, optical phased array beam tracking, tunable optical filters, sensors, variable lenses, tunable diffraction gratings, and other optical components.

Abstract: An optical film is provided, which displays a positive wavelength dependency across the entire wavelength region from 400 to 800 nm, and is capable of imparting a specified retardation to transmitted light with a single sheet of film. The optical film particularly, includes a thermoplastic norbornene-based resin with a specified structure formed of a structural unit (I) which imparts a positive birefringence and a structural unit (II) which imparts a negative birefringence, and which satisfies particular conditions with respect to ?NI(?), ?NII(?), ?NI(800) and ?NII(800) wherein ?NI(?) and ?NII(?) represent the difference between a refractive index Nx(?) in an x axis direction at a wavelength ?, and a refractive index Ny(?) in a y axis direction, and ?NI(800) and ?NII(800) represent the difference in refractive indexes at a wavelength of 800 nm, and the x axis represents the stretching direction and the y axis represents the in-plane direction perpendicular to the x direction.

Abstract: A method and apparatus for controlling a bias voltage of a Mach-Zehnder modulator (MZM) use a digital pilot signal and a digital correlation technique to produce a feedback signal for adjusting the bias voltage to the quadrature bias point. Embodiments of the invention include apparatuses performing a non-return-to-zero (NRZ), return-to-zero (RZ), or carrier suppressed RZ (CSRZ) high-speed optical modulation.

Abstract: A method for controlling the frequency dependence of insertion loss in an etalon-lens-fiber (ELF) optical assembly comprises defining target frequencies and insertion loss objectives therefor and adjusting the optical path length between pairs of the etalon, lens and fiber components until insertion loss objectives are achieved. Insertion loss objectives include insertion loss and insertion loss ripple objectives. The method allows for control of the frequency dependence of insertion loss and insertion loss ripple without introducing additional components, such as spectral filters, into the system.

Abstract: The present invention is directed to an electrically switchable laminate construction for applications including smart windows, and other uses and applications in which light management is desired. The electro-optical laminate construction has scattering and transparent modes of operation for dynamically controlling electromagnetic radiation flow.

Abstract: An iono-refractive structure that includes one or more ion insertion layers having a real portion and an imaginary portion of the dielectric constant is provided. While both the real portion and the imaginary portion of the dielectric constant change, the change in the imaginary portion is less than the change in the real portion at the wavelength of interest or at the operational wavelength. The iono-refractive structure may be suitable for the fabrication of or integration with tunable optical filters, wavelength-selective optical elements, active modulated interferometers, optical phase shifters, optical phased array beam steering, optical phased array beam tracking, tunable optical filters, sensors, variable lenses, tunable diffraction gratings, and other optical components.

Abstract: Optical films are provided for which the retardation generated, and the wavelength dispersion of that retardation, are able to be controlled. (1) An optical film containing a thermoplastic norbornene resin with a photoelastic coefficient (CP) within a range from 0 to 100 (×10?12 Pa?1), and a stress optical coefficient (CR) within a range from 1500 to 4000 (×10?12 Pa?1). (2) An optical film containing a thermoplastic norbornene resin either with a group represented by the general formula (2), shown below, or with at least one group selected from the general formulas (3) and (4) shown below.

Abstract: A new damage resistant and tolerant optical element is disclosed. Prior art solid or liquid host matrices are replaced by a soft crosslinked polymer or similar host material. The viscoelastic properties of the matrix host material are controlled during formation so that there are regions of different softness, of stiffness, within the matrix, to form a stiffness gradient. Preferably, the matrix will be softest at a preselected focal plane where maximum electromagnetic radiation or energy output may be expected. The host matrix is doped with an appropriate dopant having a concentration distribution, preferably such that the concentration of dopant is highest in the region where the host matrix material is most soft. Two important disclosed example embodiments are an optical limiter and a solid state dye laser.

Abstract: Provided is an optical modulator for modulating light comprising: a superlattice structure having a plurality of interleaved narrow and wide bandgap semiconductor layers, wherein wave functions of energy states of electrons and holes in different narrow bandgap layers are coupled; and a power supply that applies voltage to the superlattice structure between a first non-zero voltage and a second non-zero voltage to modulate the light.

Abstract: An element for steering electromagnetic beams. The element includes a phase change material in combination with dielectric and other layers in a multilayer optical stack. The phase change material that is reversibly transformable between two or more structural states, where different structural states differ with respect to refractive index and/or extinction coefficient. The structural state of the phase change material establishes a phase angle state for the element that dictates the direction of propagation of an output beam produced from an incident electromagnetic beam. Depending on the structural state, the element adopts one of two principal phase angle states and a binary beam steering capability is achieved in which an incident electromagnetic beam can be redirected in either of two directions. In a preferred embodiment, the output beam is a reflected beam and the element includes a phase change material sandwiched between two dielectric materials and supported by a metal layer.

Abstract: A radiation reflecting element (34), more particularly a so-called triple prism or a retro-reflector, is provided with a photonic element on a surface serving either for the passage of an electromagnetic energy beam (light) (40,43) or on one of the surfaces (30–32) serving for the deflection of the beam. The photonic element is characterized by the presence of a photonic band gap (5,7) capable of being shifted e.g. by an electric signal. Thus, with an appropriate selection of the wavelength of the light beam, the photonic element can be switched from reflective to transmissive, thereby allowing a modulation of the light beam with a high modulation depth.

Abstract: Disclosed is an electro-absorption optical modulator using a semiconductor device. The optical modulator makes use of a change in light absorption caused by displacement of an absorption curve depending on a bias voltage applied to the device. Here, a level of the light absorption depending on the bias voltage is expressed as a transfer function of output light to the applied bias, and the transfer function has a non-linear profile due to a characteristic of a material. Unlike signal modulation of a digital optical communication system, an analog optical transmission system can be subjected to deterioration in performance, because the non-linear characteristic of the transfer function for the optical modulator generates signal distortion when an electrical signal is converted into an optical signal. The typical optical modulator has an absorption layer constituted of quantum wells having the same width.

Abstract: The present invention relates to an optical modulator array that uses stepped-well continuously tunable quantum well infrared modulators in order to accomplish electronic beam modulating. The present invention involves a coherent optical beam modulating device to steer an optical beam comprising: an optical modulator array, where said optical modulator array includes a stepped quantum well doped with electrons, wherein the modulator array affects operates as at least one of a phase modulator and a light intensity modulator base upon a voltage bias applied across the modulator array. The continuous tunable quantum well modulator includes asymmetry of the unit cell that allows transitions from the ground state to the second excited state that are normally forbidden in symmetrical quantum well infrared photodetectors.

Abstract: A system and method for exploiting the dependance of a photoelastic modulator's (PEM's) resonance frequency on temperature (attributable to driving amplitude and to ambient temperature) to generally improve the performance of PEMs. In one embodiment there is provided a method and system for efficiently driving a series of multiple PEMs. To this end, each of the PEMs in a stack are separately tuned, as by controlling the power dissipated in each PEM, so that the resonance frequencies of all of the PEMs converge to a common frequency. Thus, all of the PEMs are simultaneously at resonance to ensure maximum efficiency and to maintain a selected total retardation amplitude. In another embodiment of the present invention, a single-element PEM is controlled in a manner to account for the subtle changes in the PEM's resonance frequency.

Abstract: A semiconductor modulator is disclosed which exhibits a negative alpha parameter at low operating bias. The device includes at least two barrier layers with a quantum well layer therebetween. An additional layer is formed adjacent to the quantum well layer, the additional layer having a bulk bandgap energy greater than the quantum well layer so as to form a stepped well between the barrier layers.

Abstract: A device and method for optical isolation for use in optical systems is disclosed. The device provides for a waveguide optical isolator fabricated using two arms, made of optical waveguides comprising magneto-optical material, in a Mach-Zehnder interferometer configuration. The device of the present invention operates using the TM mode of a light wave and, thus, does not require phase-matching of TM and TE modes. Further, the present invention does not use polarizers to extinguish the optical feed-back.

Abstract: A broadband optical spectrum generating apparatus 20 includes a ultrashort pulsed fiber laser 22 that generates pulsed light having a pulse width in the unit of picosecond to femtosecond, and broadband optical spectrum-generating optical fibers 24 that are connected with the ultrashort pulse fiber laser 22 via a lens 26 and have characteristics of normal dispersion, that is, a nonlinear coefficient of not less than 10 [W?1 km?1] and a magnitude of wavelength dispersion of not greater than a value 0 [ps/km/nm] with regard to a wavelength of the pulsed light. The resulting output is super continuum that is widely broadened to a wavelength band of 1400 nm to 1750 nm and is chirped to a linear characteristic.

Abstract: A liquid crystal panel modulates a light beam irradiated by a light source in accordance with image information, which includes a liquid crystal panel body having a pair of transparent substrates between which electro-optic material is sealed, and a holding frame of approximately C-shaped cross section having a base portion provided with an opening corresponding to an image formation area of the liquid crystal panel and a pair of lateral portions vertically provided on opposing sides of the base portion, the holding frame accommodating the liquid crystal panel body thereinside.

Abstract: Electroabsorption modulator (100) having a layer sequence of at least five sequential layers, having at least one light absorption layer (106) which is arranged between the first layer (101) and the third layer (102) and is set up to generate charge carriers upon irradiation of light (108) of a specific wavelength, and having at least one storage layer (104) which is arranged between the third layer (102) and the fifth layer (103) and is set up to store charge carriers.

Abstract: An EML transmitter having a band stop filter to improve the transmission characteristics before and after the transmission is provided. This is achieved by improving the chirp characteristics and the extinction ratio during the transmission of optical signals using an EML. The inventive EML transmitter includes: an EML for generating transmission light; a first lens for focusing optical signal outputs from the EML to prevent loss of the optical signals; a second lens for focusing the optical signals into a core portion of an optical line; and, a band stop filter for removing the D.C. component from the optical signals outputted by the EML.

Abstract: An optical phase modulator includes a bandpass multilayer stack, formed by a plurality of dielectric layers, preferably of GaAs and AlAs, and having a transmission function related to the refractive index of the layers of the stack, for receiving an optical input signal to be phase modulated. A phase modulator device produces a nonmechanical change in the refractive index of each layer of the stack by, e.g., the injection of free carrier, to provide shifting of the transmission function so as to produce phase modulation of the optical input signal and to thereby produce a phase modulated output signal.

Abstract: An element for reflecting, transmitting, focusing, defocusing or wavefront correction of electromagnetic radiation in the terahertz frequency range. The elements include a grid of conductive strips including active regions comprising a chalcogenide phase change material. The chalcogenide material can be in an amorphous, crystalline or partially crystalline state. The dispersive characteristics of the grid (e.g. impedance, admittance, capacitance, inductance) influence one or more of the reflection, transmission, state of focusing or wavefront characteristics of incident electromagnetic radiation through the action of a stored phase taper formed by establishing a crystallinity gradient over a series of active chalcogenide regions or domains in one or more directions of the element.

Abstract: A method of tuning an electroabsorption modulator (EAM). A reference average power loss factor for light having a reference peak wavelength that is modulated by the EAM is provided. This loss factor is based on operation of the EAM using a reference bias voltage, a reference temperature, and a reference modulation signal which has a predetermined duty cycle. Input light is coupled into the EAM and modulated using a modulation signal which has the same duty cycle as the reference modulation signal. The input power of the input light and the average output power of light emitted from the EAM are measured. These input and average output powers are used to generate an average power loss factor. The average power loss factor is compared to the reference average power loss factor and the bias voltage and/or the temperature of the EAM are adjusted to reduce differences between these loss factors.

Abstract: A photochromic synthetic resin (i.e., plastic) object characterized by a permanently increased contrast relative to the contrast of prior art photochromic synthetic resin objects, such that the photochromic synthetic resin object according to the invention exhibits improved contrast in the stationary states and in every intervening phase, including both darkening and lightening. The photochromic synthetic resin objects of the invention are particularly useful as lenses for eyeglasses, especially for sports glasses.

Abstract: An exemplary monolithic stabilized monolithic transmissive active optical device, such as an electroabsorption modulator (EAM), a variable optical attenuator (VOA), or a semiconductor optical amplifier (SOA), with an output optical tap, is formed from: a substrate; a waveguide layer; a semiconductor layer. The waveguide layer is coupled to the substrate and includes an active medium, which interacts with a predetermined wavelength of light, and is responsive to an electric signal. The electric signal is applied between the substrate and the semiconductor layer. The waveguide layer includes an output optical tap section and an active section adjacent to the output optical tap section. These sections include portions of the active medium. Further embodiments of the present invention incorporate temperature as well as bias control to improve performance of exemplary monolithic transmissive active optical devices.

Abstract: A method of fabricating a poled fiber and a dispersion compensator. The method including patterning to cover an etching-resistant material on the body portions of the cladding and on one end or both ends of the optical fiber excluding the portions to be grooved in the longitudinal direction, etching the bare portions of the cladding excluding the portions covered with the etching-resistant material, evaporating electrodes on the etched portions and applying a voltage to the electrodes, and inducing periodic poling generating optical phenomenon of the second-order nonlinearity to the optical fiber through the patterned electrodes. The compensator including a periodic poled fiber to generate a phase conjugate wave of a difference frequency between a pump light and a signal light received from a fiber coupler, and a filter to pass the phase conjugate wave coming out from the periodic poled fiber.

Abstract: Drive circuitry to provide a DC bias voltage and a high frequency modulation current to an electroabsorption modulator (EAM), including a high frequency modulation current source, a coupling capacitor, and a first DC lead. The drive circuitry may include termination circuitry. One lead of the high frequency modulation current source is electrically coupled to the first semiconductor type contact of the EAM and the other lead of the high frequency modulation current source is electrically coupled to an AC ground. The coupling capacitor includes a first electrode electrically coupled to the second semiconductor type contact of the EAM, a second electrode electrically coupled to the AC ground, and a dielectric layer between the electrodes. The first DC lead is electrically coupled to the EAM-side capacitor electrode and configured to be coupled to a first DC potential.

Abstract: An optical modulator having a good reflection characteristic over a broad band is provided, with a small semiconductor chip area, by use of a semiconductor chip on which a semiconductor optical modulator is mounted. A typical example of the optical modulator has a structure in which a semiconductor chip provided with an electro-absorption semiconductor optical modulator comprising an electrode of traveling wave modulator is mounted on a dielectric substrate provided with a transmission line, and the characteristic impedance of at least a part of the transmission line is set to be greater than the output impedance of a modulator driver circuit and the impedance of an optical modulator portion. By this, a broad band optical modulator with excellent reflection characteristic can be provided by use of a semiconductor chip which is small in area.

Abstract: A broadband optical spectrum generating apparatus 20 includes an ultra-short pulse fiber laser 22 that generates pulsed light having a pulse width in a unit of picosecond to femtosecond, and a broadband optical spectrum-generating optical fiber 24 that is connected with the ultra-short pulse fiber laser 22 via a lens 26 and has a non-linear coefficient of not less than 10 [W−1m−1] at a wavelength of the pulsed light and a magnitude of chromatic dispersion of not greater than 2 [ps/km/nm]. The pulsed light emitted from the ultra-short pulse fiber laser 22 is converted into a relatively flat super continuum over a broad band of approximately 1200 nm to 2000 nm by chromatic dispersion in the course of transmission through the broadband optical spectrum-generating optical fiber 24.