Abstract: The present invention relates to a light source apparatus that has a base structure capable of generating SC light and further having a structure that enables the shaping of the spectral waveform of the SC light, power adjustment of the SC light, or adjustment of the frequency of repetition of the pulse train that contains the SC light. For example, a light source apparatus that enables shaping of spectral waveforms comprises a seed light source that emits seed light which is a pulse train or continuous light; an optical fiber that generates SC light from the seed light, and spectrum shaping means for completely or partially changing the spectral waveform of the SC light. The shaping of the spectral waveform changes the maximum power of the seed light by changing the optical coupling efficiency of the seed light source and optical fiber, for example, thereby suitably deforms the spectrum of the SC light.

Abstract: The present invention relates generally to the field of synthetic crystal, and more particularly, this invention relates to doped low-temperature phase barium metaborate single crystal, growth method and frequency-converter. Molten salt method was adopted. The single crystal completely overcome the shortcomings of BBO with strong deliquescence, almost no deliquescence; its frequency doubling effect and optical damage threshold has improved greatly compared with the BBO; its hardness increased significantly, the single crystal with Shore hardness of 101.3 and Mohs hardness of 6, however, BBO with Shore hardness of 71.2 and Mohs hardness of 4. From the UV-Vis region transmittance curves tests, the cut-off wavelength of the single crystal is 190 nm, wavelength of absorption onset is 205 nm. BBSAG is widely applied in the fields of laser and nonlinear optics, and in terms of frequency-converter of ultraviolet and deep-ultraviolet due to its excellent properties better than BBO.

Abstract: A wavelength conversion laser device includes a laser light source which emits a laser beam, two reflective surfaces which reflect therefrom a laser beam, a wavelength converter provided between the two reflective surfaces, which converts a laser beam into a wavelength-converted laser beam, and condensing optics which condense the laser beams to be injected between the two reflective surfaces, wherein at least one of the two reflective surfaces has a curvature for reflecting a laser beam to be re-injected into the wavelength converter between the two reflective surfaces repeatedly while forming multi paths of laser beams injected into the wavelength converter at different incident angles, and the condensing optics are arranged to disperse beam waists of the laser beams in the wavelength converter, which reciprocate between the two reflective surfaces.

Abstract: The present invention relates to a display system based on photon energy up-conversion.

Abstract: Unconventional twisted ?-electron system electro-optic (EO) chromophores/compounds, compositions and related device structures. Crystallographic analysis of several non-limiting chromophores reveals, for instance, large ring-ring dihedral twist angles and a highly charge-separated zwitterionic structure in the ground state, in both solution phase and solid-state.

Abstract: A device for generating or receiving electromagnetic radiation in a frequency range from 10 GHz to 100 THz is provided. The device includes a housing and a wave guide fiber leading into the housing. The wave guide fiber is adapted for guiding pulsed laser light with a first central wavelength. Within the housing, a terahertz converter is provided for generating or receiving the electromagnetic radiation in the terahertz range. The device also includes a frequency converter for converting the light exiting from the wave guide fiber to a second central wavelength being arranged between the end of the wave guide fiber and the terahertz converter in such a way that the terahertz converter is impinged by the frequency converted light.

Abstract: The invention relates to a photo-detector comprising a light sensitive element (101) and a wavelength converter (103) arranged in front of the light sensitive element, the wavelength converter being configured to convert light of a first wavelength into light of a second wavelength and to direct the light of the second wavelength to the light sensitive element. The advantage is that a stable reading across the entire visible spectrum may be provided.

Abstract: A pump probe measuring device (1) includes an ultrashort optical pulse laser generator (11) for generating a first ultrashort optical pulse train, which becomes a pump light, and a second ultrashort optical pulse train, which becomes a probe light, a delay time adjusting unit (15) for adjusting a delay time between ultrashort optical pulse trains, a first pulse picker and a second pulse picker (13, 14) for accepting each of the first and the second ultrashort optical pulse trains and allowing only one pulse to be transmitted at an arbitrary repetition periodicity, thus reducing the effective repetition frequency of the optical pulses, a delay time modulation unit (10) for periodically changing a position through which pulses are transmitted by the first and the second pulse pickers (13, 14), an irradiation optical system (16) for applying pump light and probe light to a sample (19), a measuring unit (20) for detecting probe signals from a sample (19), and a lock-in amplifier (18).

Abstract: A wavelength conversion light source apparatus includes a fundamental wave light source configured to emit a fundamental wave, a nonlinear crystal configured to convert a wavelength of the fundamental wave by being irradiated with the fundamental wave and making the fundamental wave pass therethrough, and a movement unit configured to place the nonlinear crystal thereon and continuously move the nonlinear crystal within a plane, where a phase matching condition is not violated, so that a passage path of the fundamental wave passing through the nonlinear crystal is changed.

Abstract: A wavelength conversion element having an improved property-maintaining life and a method for manufacturing the wavelength conversion element are provided. A wavelength conversion element 10a has an optical waveguide 13. The wavelength of incoming light 101 input from one end 13a of the optical waveguide 13 is converted and outgoing light 102 is output from the other end 13b of the optical waveguide 13. The wavelength conversion element includes a first crystal 11 composed of AlxGa(1-x)N (0.5?x?1); and a second crystal 12 having the same composition as that of the first crystal. The first and second crystals 11 and 12 form a domain-inverted structure in which a polarization direction is periodically reversed along the optical waveguide 13, and the domain-inverted structure satisfies quasi phase matching conditions with respect to the incoming light 101. At least one of the first and second crystals has a dislocation density of 1×103 cm?2 or more and less than 1×107 cm?2.

Abstract: The present invention relates to a white light source, and particularly to a white light source with crystal fiber and a method for color temperature tuning thereof. The white light source of the present invention comprises a pumping source for providing a first-color light, and a gradient index lens for coupling the first-color light into a crystal fiber. The crystal fiber absorbs a portion of the first-color light and generates a second-color light and a third-color light, and a white light with high color rendering index can be obtained. The crystal fiber is made of a first rare earth element oxide and a second rare earth element oxide co-doped yttrium aluminum garnet. The color temperature of the white light can be tuned by adjusting the position of the focus of the pumping light on the end section of the crystal fiber.

Abstract: In a wavelength conversion element in which a periodic poled crystal that converts an input laser light into a laser light of a predetermined wavelength is provided on a thick-film resistance substrate including a heating unit, a heat spreader having a predetermined thermal conductivity, which equalizes a temperature distribution of the periodic poled crystal, is provided between the thick-film resistance substrate and the periodic poled crystal, and the thick-film resistance substrate and the heat spreader, and the heat spreader and the periodic poled crystal are adhered by an adhesive member having a predetermined thermal conductivity.

Abstract: The present invention provides a quantum optical data storage protocol, whose storage time is lengthened by spin population decay time from several minutes to several hours.

Abstract: An optical antenna assembly including multiple optical antenna elements, each of the optical antenna elements are arranged in a regular pattern and carried by a supporting body. The regular pattern of the plurality of optical antenna elements is nonuniform. Certain ones of the optical antenna elements are configured to respond to the one or more waves of light.

Abstract: An integrated device includes an optical element and an electrical element that are implemented on a substrate. The optical element and the electrical element are bonded by surface-activated bonding technology to a bonding portion that is formed on the substrate and made of metal material.

Abstract: An optical wavelength conversion element includes a cesium-lithium-borate crystal processed into a 10-mm long optical element cut in an orientation that allows a fourth harmonic of a Nd:YAG laser to be generated. A transmittance (Ta) at 3589 cm?1 in an infrared transmission spectrum of the optical element is used as an index that indicates a content of water impurities in the crystal and is independent of a polarization direction. An actual measurement of the transmittance Ta is at least 1%, without taking into account loss at an optically polished surface of the crystal. A wavelength conversion device, a ultraviolet laser irradiation apparatus, a laser processing system, and a method of manufacturing an optical wavelength conversion element are also described.

Abstract: A light emitting apparatus has a radiation source for emitting short wavelength radiation. A down conversion material receives and down converts at least some of the short wavelength radiation emitted by the radiation source and back transfers a portion of the received and down converted radiation. An optic device adjacent the down conversion material at least partially surrounds the radiation source. The optic device is configured to extract at least some of the back transferred radiation. A sealant substantially seals a space between the radiation source and the optic device.

Abstract: Semiconductor light converting constructions are disclosed. The semiconductor light converting construction includes a first semiconductor layer for absorbing at least a portion of light at a first wavelength; a semiconductor potential well for converting at least a portion of the light absorbed at the first wavelength to light at a longer second wavelength; and a second semiconductor layer that is capable of absorbing at least a portion of light at the first wavelength. The first semiconductor layer has a maximum first index of refraction at the second wavelength. The second semiconductor layer has a second index of refraction at the second wavelength that is greater than the maximum first index of refraction.

Abstract: A solid state lighting device including a light source capable of emitting white light including a blue spectral component and having a deficiency in a spectral region, and an optical component that is positioned to receive at least a portion of the light generated by the light source, the optical component comprising an optical material for converting at least a portion of the blue spectral component of the light to one or more predetermined wavelengths such that light emitted by the solid state lighting device includes light emission from the light source supplemented with light emission at one or more predetermined wavelengths, wherein the optical material comprises quantum confined semiconductor nanoparticles. Also disclosed is lighting fixture, a cover plate for a lighting fixture and a method.

Abstract: A light emitting apparatus has a radiation source for emitting short wavelength radiation. A down conversion material receives and down converts at least some of the short wavelength radiation emitted by the radiation source and back transfers a portion of the received and down converted radiation. An optic device adjacent the down conversion material at least partially surrounds the radiation source. The optic device is configured to extract at least some of the back transferred radiation. A sealant substantially seals a space between the radiation source and the optic device.

Abstract: A new blue extended super continuum light source is claimed. When pulses of partly coherent monochromatic “pump” radiation of essentially constant amplitude is propagating through a microstructure fibre medium within a region of anomalous dispersion of the medium, then, provided the medium has a finite nonlinear coefficient of the index of refraction, the pump pulse is subject to a modulation instability. This instability results in the generation and exponential growth of sidebands, the two closest to the “pump” frequency being the dominant ones. The modulation frequency is proportional to the square root of the power in the carrier wave. In the time domain this leads to that the interaction between the medium and the radiation results in contraction of the width of the amplitude peaks, which results in formation of a train of narrow pulses with Tera Hertz repetition rate.

Abstract: A wavelength-specific optical switch combines one or more tunable filters and bandblock reflectors such that the absorption or reflection of selected wavelength bands in the optical spectrum (visible, near infrared, or near ultraviolet) can be switched on and off. The wavelength switch is programmable, multifunctional, general-purpose, solid-state optical filter. The wavelength switch may serve as a tunable notch or bandblock filter, a tunable bandpass filter, a tunable highpass or lowpass filter, or a tunable band reflector. The wavelength switch has particular, but not exclusive, application in optics as a filter, band reflector, and as a means of isolating particular wavelengths or wavelength bands from a collimated light stream for transmission to, or rejection from, a sensor.

Abstract: A method for operating a wavelength-converted light source includes directing a pump beam having a fundamental wavelength from the laser source into an input facet of the wavelength conversion device such that a wavelength-converted output beam is emitted from an output facet of the wavelength conversion device in the field of view of an optical detector. A physical property of the wavelength conversion device is varied within individual ones of a succession of consecutive speckle reduction intervals having durations less than the integration time of the optical detector. The physical property of the wavelength conversion device is varied by an amount that is sufficient to change in a phase-matched (PM) wavelength of the wavelength conversion device. The fundamental wavelength of the pump beam is thereafter adjusted based on the change in the PM wavelength to maintain an efficiency of the wavelength conversion in the wavelength conversion device.

Abstract: A voltage is applied on an interdigitated electrode provided on one main face of a single-domain ferroelectric single crystal substrate to form a periodic domain inversion structure. The interdigitated electrode is then removed. The optical waveguide is then formed in the substrate. An optical intensity center P1 of the optical waveguide is kept away from a location P0 of the end of the interdigitated electrode.

Abstract: The present invention relates to a device for modifying, e.g. narrowing the wavelength range of a spectrum of light.

Abstract: A novel phase-coded aperture, associated imaging system, and design method is disclosed. The optical imaging system includes a coded-aperture followed optically by a detector array and includes an image processor. A diffraction pattern in the form of a band-limited uniformly redundant array is formed on the detector array when focusable radiation from a point source in object space is modulation by the transmission function of the coded-aperture. Since diffraction effects cannot be ignored in the optical regime, an iterative phase retrieval method is used to calculate the phase-coded aperture transmission function. Correlation type processing can be applied for the image recovery.

Abstract: An optical circuit is described which may include an SOA-MZI circuit providing an output signal; and a polarization filtering device (PFD) configured to receive the output signal of the SOA-MZI and to provide at least one signal at the output of the PFD.

Abstract: A device comprising a conversion channel including: a first end configured to accept ambient electromagnetic radiation, the ambient electromagnetic radiation having an initial frequency, a second end configured to allow the ambient electromagnetic radiation to exit, and at least two opposing walls connecting the first end and the second end, wherein the at least two opposing walls include one or more crystals, the at least two opposing walls being separated by at least one-half of a wave length; wherein when the ambient electromagnetic radiation interacts with the one or more crystals of the at least two opposing side walls, the initial frequency of the ambient electromagnetic radiation being repeatedly increased to an optimal frequency is provided.

Abstract: A method and system for remotely imaging a magnetic field within an atom cloud is provided. An atom sample held in a magneto-optical trap is released, and the released atom cloud is illuminated by a Raman beam. Resonant atoms having certain velocities will absorb photon momenta from the Raman beam. The velocities of those resonant atoms will change in response to the absorbed momenta, causing a change in the travel distance of those atoms as compared with non-resonant atoms. The atom cloud is imaged by an imaging device such as a CCD camera and the presence of the resonant atoms is shown in the images as bright lines in the atom cloud. The distance traveled by the resonant atoms and therefore the separation of the lines in the image is a function of the magnetic fields in the atom cloud.

Abstract: A wavelength conversion device includes a supporting body, a wavelength conversion substrate of a Z-plate of a ferroelectric single crystal with a periodic domain inversion structure formed therein and having a thickness “T” of 10 ?m or more and 100 ?m or less, a buffer layer provided on a bottom face of the wavelength conversion substrate, and an organic resin adhesive layer adhering the supporting body and buffer layer with a thickness of 0.6 ?m or more and 2.0 ?m or less.

Abstract: A nonlinear optical crystal having a chemical formula of YiLajAlkB16O48, where 2.8?i?3.2, 0.8?j?1.2, i and j sum to about four, and k is about 12 is provided. The nonlinear optical crystal is useful for nonlinear optical applications including frequency conversion. Nonlinear optical crystals in a specific embodiment are characterized by UV blocking materials (e.g., some transition metals and lanthanides) at concentrations of less than 1,000 parts per million, providing high transmittance over portions of the UV spectrum (e.g., 175-360 nm).

Abstract: A sample of nonlinear optical material for use in a nonlinear optical device contains a grating comprising alternating regions of inverted and non-inverted nonlinear coefficient of the material, with the regions separated by boundaries positioned such that the grating can provide quasi-phase matching of a selected nonlinear optical interaction, and compensate for phase mismatch arising from the Gouy phase shift of one or more focused optical beams involved in the interaction. The boundary positions can be calculated for second harmonic generation or optical parametric generation and oscillation.

Abstract: An imaging system is provided that includes a optical pulse generator for providing an optical pulse having a spectral bandwidth and includes monochromatic waves having different wavelengths. A dispersive element receives a second optical pulse associated with the optical pulse and disperses the second optical pulse at different angles on the surface of the dispersive element depending on wavelength. One or more focal elements receives the dispersed second optical pulse produced on the dispersive element. The one or more focal element recombine the dispersed second optical pulse at a focal plane on a specimen where the width of the optical pulse is restored at the focal plane.

Abstract: Lasers configured for intracavity harmonic generation of second and higher order harmonic laser beam energy include mode-matching optics, such as a curved mirror, for recycling an unused portion of an intermediate harmonic laser beam energy (e.g., second harmonic laser beam energy) to improve higher order harmonic laser beam energy generation efficiency (e.g., third or higher order harmonic laser beam energy generation efficiency) without sacrificing beam quality of the higher order harmonic laser beam energy. The curved mirror may be positioned out of a resonant laser cavity of the laser. A radius of curvature and a position of the curved mirror are selected so that a beam radius and a beam divergence of the recycled second harmonic laser beam energy are essentially the same as a beam radius and a beam divergence of incoming second harmonic laser beam energy everywhere along a beam path of the incoming second harmonic laser beam.

Abstract: A light source including a light emitting unit, a nonlinear medium, and a resonant grating. The light emitting unit is arranged to emit a first light into the nonlinear medium. The nonlinear medium is arranged to generate a second light such that an optical frequency of the second light is higher than an optical frequency of the first light. The resonant grating is arranged to stabilize an optical frequency of the first light by providing optical feedback to the light emitting unit.

Abstract: A method for aligning an optical package includes applying a dither waveform and an advancement waveform to a drive mechanism. The optical package includes a semiconductor laser operable to emit an output beam with a first wavelength, a wavelength conversion device operable to convert the output beam to a second wavelength, adaptive optics configured to optically couple the output beam into a waveguide portion of an input facet of the wavelength conversion device, and a drive mechanism coupled to the adaptive optics and configured to adjust a position of the output beam. The dither waveform oscillates the adaptive optics back and forth in first and second directions to oscillate the output beam on the input facet. The advancement waveform advances the adaptive optics in an adjustment direction. Rising and falling edge times of the dither waveform are greater than rising and falling edge times of the advancement waveform.

Abstract: An optical antenna collects, modifies and emits energy at light wavelengths. Linear conductors sized to correspond to the light wavelengths are used. Nonlinear junctions of small dimension are used to rectify an alternating waveform induced upon the conductors by the lightwave electromagnetic energy. The optical antenna and junctions are effective to produce harmonic energy at light wavelengths. The linear conductors may be comprised of carbon nanotubes that are attached to a substrate material, which may then be connected to an electrical port.

Abstract: The invention relates to a broadband Terahertz (THz) radiation generation and detection system and method. THz radiation is generated by optical rectification of an ultrashort pump pulse of a first wavelength having a duration in the picosecond- or sub-picosecond range in a first nonlinear optical crystal. The THz radiation is detected by electro-optic sampling or another appropriate method of a probe beam having a second wavelength in a second nonlinear optical crystal. According to the invention, at least one of the following conditions is fulfilled: a) the first wavelength is different from the second wavelength; b) the material of the first nonlinear optical crystal is different from the material of the second nonlinear optical crystal.

Abstract: A first laser beam 1a and a second laser beam 1b are incident on a difference frequency mixing unit, and the two laser beams are overlapped in the difference frequency mixing unit, thereby generating a terahertz wave whose frequency is a frequency difference between the two laser beams. Each laser beam has a spatial spread in a frequency gradient direction, and a spatial frequency distribution of each laser beam is a distribution in which a magnitude of a frequency gradually increases in the frequency gradient direction. Accordingly, a frequency difference between the two laser beams is equal in each position in an overlapping region of the two laser beams. A terahertz wave of a single frequency is generated from this overlapping region. By spatially shifting the first laser beam and the second laser beam with respect to each other in the frequency gradient direction, the frequency difference in the overlapping region is changed, so that the single frequency is changed.

Abstract: To provide a terahertz beam scanning apparatus and method that can scan a terahertz beam at high speed over a wide angle. The terahertz beam scanning apparatus includes: a laser device 12 that generates a first laser beam 1 and a second laser beam 2 having different wavelengths; a laser optical system 14 that focuses the first laser beam 1 and the second laser beam 2 on a same common focal point 14b; and a terahertz generator 16 that is located at the common focal point and generates a terahertz beam 4 by difference frequency mixing. The laser optical system 14 is configured to be capable of changing a relative incidence ?i between the first laser beam and the second laser beam to the terahertz generator.

Abstract: In a photon pair generating apparatus for generating a pair of correlated photons by hyper-parametric scattering, a light-shaping section irradiates an optical resonator with two beams of light of equal wavelength from different directions, and the optical resonator is configured to emit two correlated photons of different wavelengths in one direction as a pair of correlated photons. This makes it possible to provide a photon pair generating apparatus capable of achieving generation of a pair of correlated photons by a simpler configuration.

Abstract: Master oscillator power amplifier (MOPA) apparatus includes two seed-pulse sources coupled to a single fiber amplifier including one or more stages of amplification. One of the seed-pulse sources is a single-mode source generating pulses having a duration selectively variable between about 0.1 ns and 10 ns. The other seed-pulse source is a multi-mode source generating pulses having a duration selectively variable between about 1 ns and 10 ?s. Selectively operating one or the other of the seed-pulse sources provides that the apparatus can deliver pulses selectively variable in a range between about 0.1 ns and 10 ?s.

Abstract: A light emitting apparatus has a radiation source for emitting short wavelength radiation. A down conversion material receives and down converts at least some of the short wavelength radiation emitted by the radiation source and back transfers a portion of the received and down converted radiation. An optic device adjacent the down conversion material at least partially surrounds the radiation source. The optic device is configured to extract at least some of the back transferred radiation. A sealant substantially seals a space between the radiation source and the optic device.

Abstract: A two-dimensional image display device using a Yb-doped clad pump fiber which is a rare-earth-doped fiber as a laser activation substance, whereby a peak of a fluorescence spectrum can be significantly increased as compared with a case of using an oxide crystal, and a variation width of an oscillation wavelength can be increased. Further, since the rare-earth-doped fiber is used as a fiber amplifier without providing laser mirrors at both ends thereof, control for a resonator length, which has been required in a conventional device (wherein an oxide crystal is used as a laser medium), is dispensed with, and thereby high-speed wavelength control is achieved, resulting in reduction in speckle noise when it is mounted on a two-dimensional image display device.

Abstract: A wavelength conversion laser light source includes a fundamental wave laser light source (1) to generate a fundamental wave; a first mirror and a second mirror (4, 5), arranged so as to oppose each other; a wavelength conversion element (3) which is arranged between the first mirror and the second mirror and converts the wavelength of the fundamental wave; and a temperature control portion (8) to control the temperature of the wavelength conversion element.

Abstract: The present invention relates to an apparatus and method for simultaneously generating terahertz wave and supercontinuum, and a spectroscopy method using the apparatus and method, in which terahertz wave and supercontinuum can be efficiently and simultaneously generated by a single device after taking into consideration the problems of conventional methods in which terahertz wave and supercontinuum were generated by separate devices. The apparatus for simultaneously generating terahertz wave and supercontinuum, includes a terahertz wave generation unit for generating a terahertz wave, and a supercontinuum generation unit for generating a supercontinuum based on nonlinear effect, wherein the terahertz wave and the supercontinuum are simultaneously generated using a single input light signal.

Abstract: A method of inducing a periodic variation of nonlinearity value in a sample of ferroelectric material comprises arranging a pair of electrodes on opposite faces of the sample, one electrode defining a desired pattern of nonlinearity variation, applying a pre-bias voltage across the sample for a predetermined time using the electrodes, the pre-bias voltage being less than the coercive field of the ferroelectric material; and after the predetermined time, applying a current-controlled poling voltage across the sample using the electrodes, to produce domain inversion in the sample according to the desired pattern of nonlinearity variation. The pre-bias voltage may be 75% of the coercive field or more, and applied for a pre-determined time between 1 and 100 seconds.

Abstract: An efficient broadband crystal for wavelength conversion, the crystal being a quasi-phase matched non-linear crystal, having an aperiodic poled structure, each period being tuned, and wherein said tuning varies adiabatically along a length of said crystal from a first end wherein said tuning is a strong negative mismatch to a second end wherein said tuning is a strong positive mismatch or vice versa. The crystal is able to provide efficient wavelength conversion over a range of frequencies.

Abstract: Two, three dimensional color displays having uniform dispersion of red, green and blue visible light emitting micron particles. Pumping at approximately 976 nm can generate green and red colors having an approximately 4% limit efficiency. One source can generate three colors with approximately limit efficiency. Modulators, scanners and lens can move and focus laser beams to different pixels forming two dimensional color images. Displays can be formed from near infrared source beams that are simultaneously split and modulated with micro electro mechanical systems, spatial light modulators, liquid crystal displays, digital micromirrors, digital light projectors, grating light valves, liquid crystal silicon devices, polysilicon LCDs, electron beam written SLMs, and electrically switchable bragg gratings. Pixels containing: Yb,Tm:YLF can emit blue light, Yb,Er(NYF) can emit green light, and Yb,Er:KYF and Yb,Ef:YF3 can emit red light.

Abstract: Methods and compositions for using an up-conversion phosphor as an emitting material in a reflective displays and Polymer compositions for display mediums, and blue green red (BRG) display mediums. Roles of the pumping duration and character on the temperature and the efficiency of the up-conversion process in (Ytterbium, Erbium or Thulium) co-doped fluoride crystals are set forth. Methods, compositions and display mediums for using up-conversion phosphors in both reflective and transmissive displays in which the substrate and pixel shapes are designed to maximally remove heat deposited in the emitting material and thereby improve the efficiency of up conversion.