Abstract: Solid state lasers are disclosed herein. An example laser disclosed herein includes a monolithic body having a first end and a second end. The monolithic body includes a first reflector disposed on the first end, a second reflector disposed on the second end, and a solid state gain medium and a Q-switch disposed between the first reflector and the second reflector. The example laser also includes a pump source to cause a population inversion in the solid state gain medium to cause the monolithic body to output a laser pulse. Various applications of the solid state laser are also disclosed herein.

Abstract: In some embodiments, methods, apparatus, and systems may operate to determine downhole tool standoff using a nuclear tool and photon activity, and to correct acoustic measurements using the standoff.

Abstract: A direction determination device for determining a direction of a source of ionizing radiation relative to the direction determination device includes at least two radiation detection devices with longitudinally designed detection volumes, the at least two radiation detection devices are arranged at an angle relative to one another. A first radiation detection device is designed as a symmetry-maintaining angle-dependent radiation detection device. A second radiation detection device is designed as a symmetry-breaking angle-dependent radiation detection device.

Abstract: A sensor for a laser may contain an at least partially transparent plastic with a fluorescent material that receives laser light at one frequency and creates light inside the transparent plastic with a second, different frequency. The light at the second frequency may travel through the plastic to an electronic sensor mounted against the transparent plastic. The sensor may be several feet in length or longer and still detect a single impinging Class I or Class II laser beam. In systems where the position of the laser may be known, a set of linear gain coefficients may be determined to calibrate the electronic sensor, as the signal strength of a received signal may decay with the distance from the electronic sensor to the location where the laser beam impinges the plastic element.

Abstract: A method for detecting azimuthal angle of a heat source includes a preparing step and a detecting step. The preparing step includes: detecting a unit period (Tc) by rotating a target positioning portion through one circle, and aligning the target positioning portion with an aligning member. The detecting step includes: driving the target positioning portion to rotate. The position of the aligning member defines an initial azimuthal position. When an infrared signal emitted from the external heat source is transmitted into an infrared sensor via the target positioning portion, a transmitting time is defined as a time point (Ts) of the heat source, and an angle between the target positioning portion and the initial azimuthal position is defined as an azimuthal angle (?x) of the heat source, in which ?x=(Ts/Tc)×360°.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: A diagnostic imaging system includes a plurality of radiation detectors (20) configured to detect radiation events emanating from an imaging region. The system includes a calibration phantom (14) configured to be disposed in the imaging region spanning substantially an entire field of view and to generate radiation event pairs that define lines-of-response, wherein the calibration phantom is thin such that each LOR intersects the calibration phantom along its length, the thickness of the phantom being smaller than the length of the LORs. A calibration processor (24) receives input of the radiation detectors and calculates an incidence angle independent crystal delay Ti for each detector. The calibration processor (24) constructs a first look-up table for the timing correction of each LOR and a second look-up table for the angle depth of interaction correction for each crystal by combining Ti and ?i.

Abstract: The invention concerns a method for determining the depth of an interaction in a pixellated gamma radiation detector characterized in that it comprises the following steps: —detecting first photons on the detector (10); —measuring the arrival time (Tpc) of said first photons on the detector (10) for a central pixel; —measuring the arrival time (Tpa) of the first photons in a pixel adjacent to said central pixel; —comparing the time (Tpa) with the time (Tpc) in order to estimate the depth of interaction (Z) owing to the different light propagation speeds in adjacent pixels; —integrating the radiation emitted over the whole of the emission of a crystal of the detector in order to determine the energy of the interaction; and —recording the integral of the energy emitted by this detection. The invention further concerns a pixellated gamma radiation detector for implementing the above method.

Abstract: A system for acquisition of tomographic measurement data from measurement signals (S) of positron emission tomography (PET) or single-photon emission computed tomography (SPECT) detectors, the system comprising: a front-end electronic assembly (2) configured to convert the measurement signals (S) into digital and analog signals (DAS); a measurement electronics assembly (3) comprising time to digital converter (TDC) modules (31) configured to determine times (T) of pulses in digital signals (DS).

Abstract: A method includes detecting currently existing dose rates while a worker is performing an operation within a Radiologically Controlled Area (RCA) and visually outputting to the worker a dosage rate map of ionizing radiation within the RCA. The visual output can be visually depicted on a display that is worn by the worker during the operation and that is situated in proximity to the worker's eye. The position of the worker within the RCA can be stored in conjunction with the measured dose rate as detected by a dosimeter worn by the worker at such position, potentially also with a time stamp. These data can then be employed to generate the dosage rate map of the RCA that shows the various dose rates at various locations within the RCA and that can be visually output for viewing by the worker or other personnel outside the RCA.

Abstract: A semiconductor sensor system, in particular a bolometer, includes a substrate, an electrode supported by the substrate, an absorber spaced apart from the substrate, a voltage source, and a current source. The electrode can include a mirror, or the system may include a mirror separate from the electrode. Radiation absorption efficiency of the absorber is based on a minimum gap distance between the absorber and mirror. The current source applies a DC current across the absorber structure to produce a signal indicative of radiation absorbed by the absorber structure. The voltage source powers the electrode to produce a modulated electrostatic field acting on the absorber to modulate the minimum gap distance. The electrostatic field includes a DC component to adjust the absorption efficiency, and an AC component that cyclically drives the absorber to negatively interfere with noise in the signal.

Abstract: Noise of signals in an image sensor is reduced. A pixel circuit generates a reset signal of a predetermined initial voltage and an exposure signal of a signal voltage according to an exposure amount of light in order. An analog-digital conversion unit performs a reset sampling process of converting the reset signal into a first digital signal at a predetermined reset sampling interval and an exposure sampling process of converting the exposure signal into a second digital signal at an exposure sampling interval that does not exceed twice the predetermined reset sampling interval in order. A detection unit detects the light based on the first digital signal and a second digital signal.

Abstract: Accurate radioactive surface contamination measurement, regardless of the size of the hand of the subject, is obtained with a radiation monitor having a hand monitoring section including a first detecting unit that may be fixed and a second detecting unit that may be movable arranged opposite one another, an insertion opening connected to an insertion space defined between the units into which the hand is inserted, and a displacing mechanism that displaces the first detecting unit and the second detecting unit relatively to each other into closer proximity upon insertion of the hand. The hand monitoring section detects radioactive rays emitted from radioactive materials attracted to the hand of the subject with one of the palm of the hand or the back of the hand being made to face the fixed detecting unit side and the other being made to face the movable detecting unit side.

Abstract: A positron emission tomography (PET) detector assembly is provided. The PET detector assembly includes a plate having a first side and an opposite second side, the plate being fabricated from a thermally conductive material. The PET detector assembly also includes multiple PET detector units coupled to the first side of the plate. The PET detector assembly further includes a readout electronics section coupled to the second side of the plate, wherein, during operation, the readout electronics section generates heat that is transferred to the plate. The plate comprises a heat pipe disposed within the plate and configured to extract the heat from the plate and to transfer the heat away from the plate.

Abstract: An apparatus for high resolution positron emission tomography (PET) imaging. The apparatus includes at least a first detector and a second detector arranged to detect gamma rays traveling from a target area, the first detector and the second detector being a detector pair. There is at least one collimator for filtering gamma rays reaching the first and second detectors. The collimator defines respective passages filtering gamma rays reaching the respective first and second detectors, the passages being defined to filter for only gamma ray pairs traveling from the target area at a predetermined range of angles with respect to each other, the predetermined range of angles being in the range of 180°-?E, where ?E is less than 1° and greater than 0°.

Abstract: The present disclosure describes structured light projection in which a structured light projector includes a light emitter and a compound patterned mask. The mask includes a spacer substrate that is transparent to a wavelength of light emitted by the light emitter. On a first side of the spacer substrate is a first reflective surface having apertures therein to allow light to pass through. Lenses are arranged to focus light, produced by the light emitter, toward the apertures in the first reflective surface. A second reflective surface on a second side of the spacer substrate opposite the first side has apertures therein to allow light passing through the spacer substrate to exit the compound patterned mask.

Abstract: A method and system for analyzing a core sample from a wellbore, where the analysis takes place in the field and proximate the wellbore. The system includes trailers adjacent one another. One of the trailers can include a unit for scanning the core sample and obtaining information within the sample. Other trailers can include units that further analyze the core, such as by grinding, laser spectroscopy, and Raman spectroscopy. The core sample scanning involves a computerized tomography (CT) scan, where a length of core is analyzed in the scanning unit. The unit includes a manipulator system for moving the core sample through a rotating scan source in the scanning unit.

Abstract: A method and apparatus are provided for generating a thermal image of a target. The method comprises: at one or more electro-magnetic transducers, receiving long wave infra-red (LWIR) radiation emitted from the target; illuminating the electro-magnetic transducers with radiation being transmitted wavelengths that belong to Near Infra-Red (NIR) band and/or that belong to the visible (VIS) band; converting at least part of the radiation received as LWIR radiation to energy at the NIR band and/or at the VIS band; and generating a thermal image based on the energy retrieved after converting at least part of the LWIR radiation received, to energy at the NIR band and/or at the VIS band, and wherein receiving the LWIR radiation and illuminating the electro-magnetic transducers, are carried out simultaneously.

Abstract: A method of preparation and optical analysis of a solid sample by multiple internal reflection infrared spectroscopy comprising: obtaining a least one substrate that is transparent to infrared light and comprises at least a main front face and a main rear face; producing at least one solid sample on the main front face of the substrate; installing around at least one part of the sample an element comprising a chamber having an aperture that opens onto the solid sample and defines a leaktight interaction zone (Zi) in relation to the outside of the chamber; feeding the chamber with a fluid with controlled parameters to control the environment in the leaktight interaction zone; sending an infrared light beam through the substrate; and recovering the beam after it has undergone multiple internal reflections in the substrate.

Abstract: An embodiment of the present invention provides a continuous-wave terahertz generation and detection device using a photomixing technique, the device including: first and second light source units configured to output continuous-wave laser light sources, which have single wavelength and different frequencies, to generate optical signals; a first electro-optic phase modulator configured to shift a frequency of the optical signal generated by the first light source unit, and a second electro-optic phase modulator configured to shift a frequency of the optical signal generated by the second light source unit; a first optical amplifier configured to receive and amplify the optical signal whose frequency is shifted by the first electro-optic phase modulator and the optical signal generated by the second light source unit, and a second optical amplifier configured to receive and amplify the optical signal whose frequency is shifted by the second electro-optic phase modulator and the optical signal generated by the