Abstract: The present invention relates, in general terms, to X-ray detecting films and uses thereof. The present invention also relates to methods of fabricating the X-ray detecting films. In particular, the X-ray detecting film comprises persistent luminescent nanoparticles dispersed within a flexible polymer matrix, wherein the persistent luminescent nanoparticles are dispersed in the flexible polymer matrix at a concentration of about 0.1% to about 100%.

Abstract: A nanocrystal scintillator that contains a thin-film layer of perovskite-based quantum dots coated on a substrate layer. The quantum dots each have a formula of CsPbXaY3-a, CH3NH3PbX3, or NH2CH?NH2PbX3, in which each of X and Y, independently, is Cl, Br, or I, and a is 0-3. The substrate layer is an aluminum substrate, a fluoropolymer substrate, a fiber optic plate, a ceramic substrate, or a rubber substrate. Also disclosed are an ionizing radiation detector and an ionizing radiation imaging system containing such a nanocrystal scintillator.

Abstract: A nanocrystal scintillator that contains a thin-film layer of perovskite-based quantum dots coated on a substrate layer. The quantum dots each have a formula of CsPbXaY3-a, CH3NH3PbX3, or NH2CH?NH2PbX3, in which each of X and Y, independently, is Cl, Br, or I, and a is 0-3. The substrate layer is an aluminum substrate, a fluoropolymer substrate, a fiber optic plate, a ceramic substrate, or a rubber substrate. Also disclosed are an ionizing radiation detector and an ionizing radiation imaging system containing such a nanocrystal scintillator.

Abstract: The present invention provides a spectroscopic system having a first tunable filter module, a second tunable filter module, an optical detector and a signal processing unit. The first tunable filter module includes a first tunable filter and corresponding control unit. The second tunable filter module includes a second tunable filter and corresponding control unit. The second tunable filter is configured in series with the first tunable filter, and the second tunable filter is selected so that the free spectral range of the second tunable filter matches the half-peak width of the first tunable filter. The optical detector is configured to receive wide wavelength bands of electromagnetic radiation transmitted through the first tunable filter and the second tunable filter and to generate one or more electrical signals indicative of electromagnetic radiation intensity as a function of wavelength.

Abstract: The present invention is related to a Fourier-transform spectrometer arrangement comprising a first polarizer, a birefringent plate, a pair of birefringent wedges, a second polarizer, a photo detector, and a control unit. According to the invention, the cross sections of the two birefringent wedges of the birefringent wedge pair are similar triangles, the first wedge is fixed, the second wedge is capable of linearly movement along the side, the optic axes of the pair of birefringent wedges are parallel to each other and orthogonal to the optic axis of the birefringent plate, the polarization of the first polarizer is in 45 degrees with the optical axis of the birefringent plate, the polarization of the first polarizer is also in 45 degrees with the optical axis of the pair of birefringent wedges, the polarization of the second polarizer is parallel, or orthogonal, to the polarization of the first polarizer.

Abstract: A polarization imaging apparatus measures the Stokes image of a sample. The apparatus consists of an optical lens set, a first variable phase retarder (VPR) with its optical axis aligned 22.5°, a second variable phase retarder with its optical axis aligned 45°, a linear polarizer, a imaging sensor for sensing the intensity images of the sample, a controller and a computer. Two variable phase retarders were controlled independently by a computer through a controller unit which generates a sequential of voltages to control the phase retardations of the first and second variable phase retarders. A auto-calibration procedure was incorporated into the polarization imaging apparatus to correct the misalignment of first and second VPRs, as well as the half-wave voltage of the VPRs. A set of four intensity images, I0, I1, I2 and I3 of the sample were captured by imaging sensor when the phase retardations of VPRs were set at (0,0), (?,0), (?,?) and (?/2,?), respectively.

Abstract: A polarization imaging apparatus measures the Stokes image of a sample. The apparatus consists of an optical lens set, a first variable phase retarder (VPR) with its optical axis aligned 22.5°, a second variable phase retarder with its optical axis aligned 45°, a linear polarizer, a imaging sensor for sensing the intensity images of the sample, a controller and a computer. Two variable phase retarders were controlled independently by a computer through a controller unit which generates a sequential of voltages to control the phase retardations of the first and second variable phase retarders. A auto-calibration procedure was incorporated into the polarization imaging apparatus to correct the misalignment of first and second VPRs, as well as the half-wave voltage of the VPRs. A set of four intensity images, I0, I1, I2 and I3 of the sample were captured by imaging sensor when the phase retardations of VPRs were set at (0,0), (?,0), (?,?) and (?/2,?), respectively.

Abstract: A polarization imaging apparatus measures the Stokes image of a sample. The apparatus consists of an optical lens set 11, a linear polarizer 14 with its optical axis 18, a first variable phase retarder 12 with its optical axis 16 aligned 22.5° to axis 18, a second variable phase retarder 13 with its optical axis 17 aligned 45° to axis 18, a imaging sensor 15 for sensing the intensity images of the sample, a controller 101 and a computer 102. Two variable phase retarders 12 and 13 were controlled independently by a computer 102 through a controller unit 101 which generates a sequential of voltages to control the phase retardations of VPRs 12 and 13. A set of four intensity images, I0, I1, I2 and I3 of the sample were captured by imaging sensor 15 when the phase retardations of VPRs 12 and 13 were set at (0,0), (?,0), (?,?) and (?/2,?), respectively Then four Stokes components of a Stokes image, S0, S1, S2 and S3 were calculated using the four intensity images.

Abstract: A polarization imaging apparatus measures the Stokes image of a sample. The apparatus consists of an optical lens set 11, a linear polarizer 14 with its optical axis 18, a first variable phase retarder 12 with its optical axis 16 aligned 22.5° to axis 18, a second variable phase retarder 13 with its optical axis 17 aligned 45° to axis 18, a imaging sensor 15 for sensing the intensity images of the sample, a controller 101 and a computer 102. Two variable phase retarders 12 and 13 were controlled independently by a computer 102 through a controller unit 101 which generates a sequential of voltages to control the phase retardations of VPRs 12 and 13. A set of four intensity images, I0, I1, I2 and I3 of the sample were captured by imaging sensor 15 when the phase retardations of VPRs 12 and 13 were set at (0,0), (?,0), (?,?) and (?/2,?), respectively Then four Stokes components of a Stokes image, S0, S1, S2 and S3 were calculated using the four intensity images.

Abstract: An electro-optic Q-switch for generating sequence of laser pulses was disclosed. The Q-switch comprises a quadratic electro-optic material and is connected with an electronic unit generating a radio frequency wave with positive and negative pulses alternatively.

Abstract: An electro-optic Q-switch for generating sequence of laser pulses was disclosed. The Q-switch comprises a quadratic electro-optic material and is connected with an electronic unit generating a radio frequency wave with positive and negative pulses alternatively.

Abstract: An optical switch for switching an incoming light signal to one of a number of output ports in a polarization independent manner. The optical switch includes a walk-off device, and a compensator which compensates for walk-off distance variations of two polarized beams, with orthogonal polarization directions, associated with the walk-off device.

Abstract: An optical switch for switching an incoming light signal to one of a number of output ports in a polarization independent manner. The optical switch includes a walk-off device, and a compensator which compensates for walk-off distance variations of two polarized beams, with orthogonal polarization directions, associated with the walk-off device.

Abstract: A coupler which couples a light signal from an input port to two more output ports. The coupler includes a multifaceted prism which separates an incoming light signal into selective portions and deflects these portions in different directions to the respective output ports. A lens is positioned between the output ports and the prism to focus the light signal from the prism to the output ports.

Abstract: An apparatus and method for filtering an optical input is disclosed. In an illustrative embodiment, an optical input is split into polarization components along separate paths. The polarization components are then fed into a first electro-optic device that includes a set of electrodes across which a voltage is applied to adjust a wavelength transmission characteristic of the device. A section of the first device positioned between the electrodes preferably has a birefringence that is adjusted depending on the voltage applied across the electrodes. The adjusted components of the optical input are thereafter combined to produce an optical output. Accordingly, the optical input can be attenuated based on the voltage applied to electrodes of the first electro-optic device.

Abstract: An apparatus and method for filtering an optical input is disclosed. In an illustrative embodiment, an optical input is split into polarization components along separate paths. The polarization components are then fed into a first electro-optic device that includes a set of electrodes across which a voltage is applied to adjust a wavelength transmission characteristic of the device. A section of the first device positioned between the electrodes preferably has a birefringence that is adjusted depending on the voltage applied across the electrodes. The adjusted components of the optical input are thereafter combined to produce an optical output. Accordingly, the optical input can be attenuated based on the voltage applied to electrodes of the first electro-optic device.

Abstract: A polarization transformer includes at least one plate of transparent polycrystalline material which has an optical axis oriented perpendicular to a propagation direction of incident radiation having a first polarization state. The plate includes electrodes for applying an electric field across a plane of the plate perpendicular to the propagation direction so as to provide controlled phase change such that the polarization of radiation transmitted through the polarization transformer is transformed from the first polarization state to a second polarization state. The plate in a preferred embodiment comprises a ferroelectric complex oxide such as lead lanthanum zirconate titanate (PLZT) material. Such a material provides devices that have very fast response (on the order of microseconds) and low insertion loss.

Abstract: An optical modulator is provided to control the intensity of a transmitted or reflected light. In a transmission mode, a separator splits arbitrarily polarized light into two polarization rays and one is made to travel a separate path from the other. A recombiner causes the two rays to recombine at an output unless an electro-optic phase retarder changes the polarization of the two rays, in which case, both of them miss the output by an amount which is a function of the voltage on the retarder. A normally-off version with low polarization mode dispersion is obtained by changing the orientation of the recombiner. A normally-on version with low polarization mode dispersion is obtained with a passive polarization direction rotator. Similar results can be obtained in a reflection mode where the input and output are on the same side of the modulator. Versions using a GRIN lens are particularly suited to modulation of light out of and back into fiber-optic cables.

Abstract: An optical modulator is provided to control the intensity of a transmitted or reflected light. In a transmission mode, a separator splits arbitrarily polarized light into two polarization rays and one is made to travel a separate path from the other. A recombiner causes the two rays to recombine at an output unless an electro-optic phase retarder changes the polarization of the two rays, in which case, both of them miss the output by an amount which is a function of the voltage on the retarder. A normally-off version with low polarization mode dispersion is obtained by changing the orientation of the recombiner. A normally-on version with low polarization mode dispersion is obtained with a passive polarization direction rotator. Similar results can be obtained in a reflection mode where the input and output are on the same side of the modulator. Versions using a GRIN lens are particularly suited to modulation of light out of and back into fiber-optic cables.

Abstract: In a device having a fiber-optic cables, one that is normally an input and one that is normally an out output for light transmission through the device, a first polarization sensitive deflector encompassing the normal input beam and a second polarization sensitive deflector encompassing the normal output beam is followed by a polarization interchanger that interchanges the polarization of beams traveling from the input to the output and leaves unchanged the polarization of beams traveling from the output to the input. This is, in turn, followed by a third polarization sensitive deflector encompassing the input beam and a fourth polarization sensitive deflector encompassing the output beam. Lastly, a lens having a reflector on the side opposite the input and output fibers reflects light beams from the input to the output and conversely.