Abstract: Systems and methods for GNSS anti-jamming using interference cancellation are described herein. In certain embodiments, a system includes an antenna that receives signals, wherein the signals comprise a weak portion associated with one or more GNSS satellites and a strong interference portion from an interfering signal source. The system also includes a GNSS anti-jammer. The GNSS anti-jammer includes an interference isolator that receives the received signals and provides an estimated strong interference portion as an output. The GNSS anti-jammer also includes a summer that subtracts the estimated strong interference portion from the received signals to create a summed signal. Further, the GNSS anti-jammer includes a local noise remover that removes noise generated by the interference isolator from the summed signal, wherein the local noise remover is a processor that digitally removes the noise. Further, the system includes a GNSS receiver coupled to receive the summed signal from the processor.

Abstract: Proposed is a GPS error correction method performed through comparison of three-dimensional HD-maps in a duplicate area, and more particularly, a method that can calculate a correction value for a GPS error by comparing three-dimensional HD-maps of a corresponding duplicate area when the duplicate area is generated on a GPS route in the process of acquiring raw data to be used in a HD-map for autonomous driving. Particularly, in the method, an accurate correction value for the GPS error can be calculated by comparing three-dimensional point cloud data acquired by utilizing basically installed LiDAR, an Inertial Measurement Unit (IMU) and the like, without using expensive equipment such as a plurality of high-precision GPS receivers, stereo cameras or the like.

Abstract: A method for performing in a positioning, navigation, tracking, frequency-measuring, or timing system is provided.

Abstract: A traffic radar system comprises a first radar transceiver, a second radar transceiver, a speed determining element, and a processing element. The first radar transceiver transmits and receives radar beams and generates a first electronic signal corresponding to the received radar beam. The second radar transceiver transmits and receives radar beams and generates a second electronic signal corresponding to the received radar beam. The speed determining element determines and outputs a speed of the patrol vehicle. The processing element is configured to receive a plurality of digital data samples derived from the first or second electronic signals, receive the speed of the patrol vehicle, process the digital data samples to determine a relative speed of at least one target vehicle in the front zone or the rear zone, and convert the relative speed of the target vehicle to an absolute speed using the speed of the patrol vehicle.

Abstract: Aspects described herein may allow for vehicle tracking. Systems and methods described herein may allow a vehicle to automatically detect the presence of a physical marker at a parking space. An image of the physical marker may be processed to determine the location of the vehicle, which may be stored and/or output for display.

Abstract: A method, implemented by a computer, for determining a position of a personal mobility device (PMD) comprises: estimating a position of a PMD based on a first wireless signal; determining whether the PMD is within an intermediate area between a first area and a second area, based on an estimated position of the PMD; determining whether the PMD moves to the second area, by using both the first wireless signal and a second wireless signal; and determining position of the PMD by using any one of the first wireless signal and the second wireless signal based on a movement of the PMD to the second area.

Abstract: It is provided a method, comprising measuring, during a period, a first time of arrival (TOA) of a first signal from a first satellite, a second TOA of a second signal from a second satellite, and a third TOA of a third signal from a third satellite; reporting, after the period has elapsed, the first TOA along with the first cell identifier and a first parameter enabling to derive a transmit time of the first signal, the second TOA along with the second cell identifier and a second parameter enabling to derive a transmit time of the second signal, and the third TOA along with the third cell identifier and a third parameter enabling to derive a transmit time of the third signal, wherein the first TOA is measured within a set first interval in the period; the second TOA is measured within a set second interval in the period; the second interval does not overlap the first interval.

Abstract: A relay point generation method includes: predicting a state of a target at a next moment; establishing a search range around the target according to the state of the target at the next moment; performing sampling within the search range, to obtain at least two location sampling points; and determining a relay point of the UAV at the next moment according to the state of the target at the next moment and the at least two location sampling points.

Abstract: System for detecting a person on an underground, which is provided with passive RFID tags (1) in a predetermined pattern, while the person is provided with a sensor module (2), which is adapted to determine the position thereof relative with respect of to the RFID tags and, preferably, the direction and/or the acceleration and/or the inclination thereof. The sensor module and/or further processing means are arranged to calculate the position of the sensor module by means of triangulation calculation. The tag pattern is formed by a regular pattern of tag clusters (4), each being formed by two tag strips, oriented in a T-shape with respect to each other. Of the T-shaped clusters, the first tag strip has an even identification code and the other tag strip has an odd Identification code. The RFID tags are applied to construction foil, which is positioned under the top layer of a floor.

Abstract: A MIMO radar sensor includes: an antenna arrangement including first and second arrays, in each of which a respective plurality of antennas are offset relative to one another in a first direction, the first and second arrays being offset from each other in a second direction that is perpendicular to the first direction, the antennas of the first and second arrays being more strongly focused in the second direction than in the first direction in each case, and, in each of at least one of the first and second antenna arrays, at least two of the antennas of the respective array being offset from one another in the second direction and the antennas of the respective array being symmetrically arranged relative to an axis running in the second direction; a high frequency element; and a control and evaluation device for evaluating output from the high frequency element regarding the antennas.

Abstract: A method for calibrating a phased array including an antenna array comprising a plurality of antenna elements, comprising the steps: measuring with a probe a first antenna element pattern of a first antenna element of the plurality of antenna elements; performing a spherical near-field to far-field transformation of the first antenna element pattern; transforming the far-field first antenna element pattern to a plane-wave spectrum; back transforming the plane-wave far-field first antenna element pattern to a reference point within the near-field of the antenna array; normalizing the first antenna element pattern according to, at least, the value at the phase center of the plane-wave near-field first antenna element pattern; and calibrating the first antenna element based, at least in the part, on the normalized first antenna element pattern.

Abstract: A number of measurements of an input spectrum is determined based on a scan mirror speed of the LiDAR system and a predetermined accuracy threshold in the number of measurements of the input spectrum. A set of signals are sampled at the LiDAR system and the set of signals are converted to a frequency domain to generate a set of sampled signals in the frequency domain. The set of signals are received consecutively over time. A set of first functions are created based on the set of sampled signals. The set of first functions are averaged to generate a second function. The second function represents a power spectrum density estimate of the set of signals. A peak value of the second function is detected to determine range and velocity information related to a target based on a corresponding frequency of the peak value of the second function.

Abstract: A sensor device has a metal sensor housing with a housing base coupled to a frame base of a metal optical frame. A device mounting plate is orthogonal to the frame base. A securing device secures an optical communication device to the device mounting plate. A barrel mounting channel has first and second sidewalls, each extending obliquely to the frame base and defining a linear translation pathway along the frame base for a metal lens barrel. A fastener secures the metal lens barrel to the first and second sidewalls. A glass lens is in contact with three protrusions extending outward from an inner annular surface of the lens barrel. The optical communication device is configured to be in optical communication with the lens and is secured in a particular position in a translation plane mutually defined by the device mounting plate and the optical communication device.

Abstract: A light detection and ranging (LIDAR) system includes a first optical source to generate a first optical beam, a first collimating lens to collimate the first optical beam, a first prism wedge of a first prism wedge pair to redirect the first optical beam, and a first focusing lens to focus the first optical beam on a front surface of a second prism wedge of the first prism wedge pair, the second prism wedge to direct the first optical beam toward an output lens.

Abstract: The embodiments described herein provide systems and methods that can facilitate increased detector sensitivity and reliability in a scanning laser device. Specifically, the systems and methods utilize detectors with multiple sensors that are configured to receive reflections of laser light pulses from objects within a scan field. These multiple sensors are configured to receive these reflections through the same optical assembly used to scan the laser light pulses out to the scan field. Furthermore, the multiple sensors are configured to at least partially cancel the effects of back reflections from within the optical assembly itself. The cancellation of the effects of back reflections from within the optical assembly can improve the sensitivity of the detector, particularly for the detection of low energy reflections of laser pulses from within the scan field.

Abstract: A lidar device having an integrated optics that has a beam deflecting unit having an optical phase array that has a multiplicity of antennas that are set up to emit electromagnetic radiation at a prespecified angle of radiation. The angle of radiation covers a prespecified field of view of the lidar device. The angle of radiation has a first angle of radiation subregion, in which electromagnetic radiation is emitted having a polarization A, and has a second angle of radiation subregion, in which electromagnetic radiation is emitted having a polarization B.

Abstract: Various technologies described herein pertain to a vertically stacked lidar assembly of an autonomous vehicle. The vertically stacked lidar assembly includes a first lidar sensor system configured to spin about an axis and a second lidar sensor system configured to spin about the axis. The first lidar sensor system is vertically stacked above the second lidar sensor system in the vertically stacked lidar assembly. Moreover, the first lidar sensor system and the second lidar sensor system are coaxially aligned. Redundancy is provided by the vertically stacked lidar assembly including the first lidar sensor system and the second lidar sensor system.

Abstract: Systems and methods for performing optical distance measurement are provided. In one aspect, a system for measuring a distance to an object comprises a light emitter configured to emit an outbound light pulse, and a light sensor configured to receive a returning light pulse reflected from the object and output an analog pulse signal representing the returning light pulse. The system also comprises a field-programmable gate array (FPGA) coupled to the light sensor. The FPGA is configured to convert the analog pulse signal to a plurality of digital signal values, and generate a plurality of time measurements corresponding to the plurality of digital signal values. The system also comprises a controller configured to calculate the distance to the object based on the plurality of digital signal values and the plurality of time measurements.

Abstract: There is provided a time of flight sensor. The time of flight sensor includes a light receiving element PD, a first signal line TRGO and a second signal line TRG180, a first transistor TGA in electrical communication with the light receiving element, the first transistor comprising a first gate in electrical communication with the first signal line TRGO, a second transistor TGB in electrical communication with the light receiving element, the second transistor comprising a second gate in electrical communication with the second signal line TRG180, and a control circuit P200 comprising at least one comparator 102A, 102B, wherein the control circuit is in electrical communication with the first and second signal lines TRGO, TRG180. The transistors TGA and TGB of the pixel circuit P100 are turned on and off so that any one of the transistors TGA and TGB is turned on, and the electric charges generated by the photodiode PD are selectively accumulated at the floating diffusion FDA and the floating diffusion FDB.

Abstract: Various embodiments of the present technology may provide methods and apparatus for region of interest histogramming. The apparatus may use a state machine in conjunction with a memory to generate a first histogram having a fixed number of bins over a first range and generate a second histogram having the fixed number of bins over a region of interest selected based on the first peak of the first histogram.

Abstract: A method for processing a point cloud generated by a light detection and ranging system, includes: receiving a first measurement generated by the light detection and ranging system; retrieving a plurality of second measurements that are adjacent to the first measurement; calculating a first parameter by using distances of the first measurement and the plurality of the second measurements, the first parameter indicating a degree of continuum of the first measurement relative to the plurality of the second measurements; and determining whether the first measurement represents a measurement of noises by using the first parameter.

Abstract: Improved calibration of a vehicle sensor based on static objects detected within an environment being traversed by the vehicle is disclosed. A first sensor such as a LiDAR can be calibrated to a global coordinate system via a second pre-calibrated sensor such as a GPS IMU. A static object present in the environment is detected such as signage. A type of the detected object is determined from static map data. Point cloud data representative of the static object is captured by the first sensor and a first transformation matrix for performing a transformation from a local coordinate system of the first sensor to a local coordinate system of the second sensor is iteratively redetermined until a desired calibration accuracy is achieved. Transformation to the global coordinate system is then achieved via application of the first transformation matrix followed by a second known transformation matrix.

Abstract: Various aspects of the subject technology relate to a lidar validation system. The lidar validation system is configured to acquire one or more lidar point clouds from a lidar unit, wherein the lidar unit comprises one or more lasers, and wherein each point cloud is a representation of a scene according to a laser in the lidar unit, the scene comprising a fiducial target. The lidar validation system is configured to generate, based on points in the one or more point clouds, a target cloud that correspond to the fiducial target, perform a rigid body processing to minimize a sum of distances from each point in the target cloud to the fiducial target, and generate lidar validation measurements based on the distances from each point in the target cloud to the fiducial target.

Abstract: A light detection and ranging (LiDAR) system includes a first optical source and a second optical source configured to emit respectively a first optical beam and a second optical beam that have opposite polarizations. The LiDAR system further includes a beam combining component to combine the first optical beam and the second optical beam into a single spatial mode optical beam and a first beam splitting component to split the single spatial mode optical beam into a plurality of single spatial mode optical beams.

Abstract: A multi-modal sensor system includes: an underlying sensor system; a polarization camera system configured to capture polarization raw frames corresponding to a plurality of different polarization states; and a processing system including a processor and memory, the processing system being configured to control the underlying sensor system and the polarization camera system, the memory storing instructions that, when executed by the processor, cause the processor to: control the underlying sensor system to perform sensing on a scene and the polarization camera system to capture a plurality of polarization raw frames of the scene; extract first tensors in polarization representation spaces based on the plurality of polarization raw frames; and compute a characterization output based on an output of the underlying sensor system and the first tensors in polarization representation spaces.

Abstract: Disclosed sensors, sensor controllers, and sensor control methods enhance transducer performance using a model-based equalization method that can be performed in the field. One illustrative method for operating a piezoelectric-based sensor includes: sensing a response of a piezoelectric transducer as a function of frequency; deriving parameter values of an equivalent circuit for the piezoelectric transducer from the response; using a squared magnitude of the equivalent circuit's transfer function to determine a system level selectivity; and adapting at least one operating parameter of the sensor based on the system level selectivity. One illustrative controller for a piezoelectric transducer includes: a transmitter that drives the piezoelectric transducer; a receiver that senses a response of the piezoelectric transducer; and a processing circuit coupled to the transmitter and to the receiver to calibrate the transducer using the foregoing method.

Abstract: A radiation position detector includes: a photodetector array constituted of unit-sized unit photodetectors; a scintillator array constituted of a plurality of tetragonal scintillator elements optically connected to the photodetector array, wherein scintillator units are each constituted of a pair of unit scintillators whose individual cross-sectional size of plane facing to right receiving surface is ¼ of the size of the unit photodetector, where at least part of which is optically connected on a surface side opposite to the right receiving surface, the scintillator units being each arranged so as to be positioned over two of the unit photodetectors; and a position evaluation unit configured to identify the scintillator unit by the presence or absence of a signal and furthermore identify one of the unit scintillators of the scintillator unit on the basis of a strength of the signal, to obtain a two-dimensional radiation detection position.

Abstract: A semiconductor device may include a plurality of single-photon avalanche diodes. The single-photon avalanche diodes may be arranged in microcells. Each microcell may be a split microcell with first and second independent microcell segments. Each microcell segment in the split microcell may have a respective single-photon avalanche diode that is coupled to an output line. The single-photon avalanche diode of each microcell segment may also be coupled to a respective resistor that is used to quench avalanches in the single-photon avalanche diode. Splitting the microcell may reduce the recovery time of each microcell. The segments of the split microcell may be positioned close together, even if susceptible to optical crosstalk. Intra-microcell isolation structures may be formed between the microcell segments. Inter-microcell isolation structures may be formed around a perimeter of the split microcell. The intra-microcell and inter-microcell isolation structures may be different.

Abstract: A guided pairing method includes generating a singles list by detecting a plurality of singles at a plurality of detector elements in a detector array, the plurality of singles falling within a plurality of detection windows; for each detection window of the plurality of detection windows in the singles list having exactly two singles of the plurality of singles, determining the line of responses (LORs) for each of the two singles of the plurality of singles; for each detection window of the plurality of detection windows in the singles list having more than two singles of the plurality of singles, determining all coincidences possible based on the more than two singles; generating a weight for said each coincidence of the coincidences based on the determined LORs for said each of the two singles of the plurality of singles; and pairing the more than two singles based on the generated weight for said each coincidence of the coincidences.

Abstract: A PET imaging system includes a gantry having a patient tunnel and a first detector unit and a second detector unit housed inside the gantry, each including a plurality of detector elements in a helical arrangement around an axial axis of the imaging system. Each of the detector elements in the second detector unit is spaced apart from a corresponding detector element in the first detector unit by an axial gap. Each detector element has an axial position. Each of the first and second detector units has its detector elements arranged so that a set of the detector elements is positioned such that each detector element in the set is offset from an adjacent detector element in the detector unit such that a maximum difference between axial positions of detector elements in each detector unit is less than or equal to the axial gap.

Abstract: A seismic source apparatus, configured to be maneuvered by a vehicle over terrain.

Abstract: A three-dimensional target motion analysis method using a line array sensor performed by a three-dimensional target motion analysis apparatus is proposed. The method may include acquiring a first conic angle between a target and the three-dimensional target motion analysis apparatus from the line array sensor at a predetermined first time point. The method may also include acquiring first attitude information including an attitude angle, a position, and a depth of the three-dimensional target motion analysis apparatus at the first time point. The method may further include analyzing a three-dimensional motion of the target by estimating a three-dimensional position of the target at the first time point based on the first conic angle and the first attitude information.

Abstract: Metal detectors are disclosed herein containing integrated positional tracking unit (20) containing the sensors and processors which provide the detection of the real-time positions of the search head (11) on the ground during metal target (1) searching process, by optical flow technique as (X, Y) points on an image frame at X, Y coordinate plane, following the verification and if required, correction of the parameters of height from the ground, horizontal and axial motions, angular position, focus distance, light quantity and quality; image processing/display unit (30), a shaft mount display and/or a screen, generating the image of the target (1) metal by matching the metal data received from the detector signal processing system (12), thereby from the search head (11) and the location and position data received from the integrated positional tracking unit (20), on a position/image matrix and presenting such image to the user visually.

Abstract: A foreign object detector includes detection coils between a transmitter coil in a transmitter device and a receiver coil in a receiver device, a power supply circuit that supplies AC power having a predetermined frequency to each detection coil through a feeder coil located to be electromagnetically coupled to each detection coil, and a detection circuit that detects, while power to be transmitted to the receiver coil is being supplied to the transmitter coil, a criteria voltage to be a criterion for foreign object detection output from each detection coil at a start of power supply from the power supply circuit and outputs a signal to stop power supply to the transmitter coil in response to the criteria voltage for any detection coil deviating from a predetermined range. The transmitter device transmits power to the receiver device contactlessly.

Abstract: Described is a precipitation observation apparatus including a bottom plate on which a precipitation gauge and a snowfall observation apparatus are provided; a determining unit which determines a state of a precipitation; a control unit which controls at least one of the precipitation gauge and the snowfall observation apparatus to measure the precipitation based on state information of the precipitation; and a calculating unit which calculates at least one of a rainfall amount, a snowfall amount, and a precipitation amount based on measurement information of the precipitation.

Abstract: Provided are a device for measuring the amount of snowfall and a method of controlling the same, the device including a bottom plate, a graduated ruler extending upward from the bottom plate, an image capturing unit configured to capture an image of the graduated ruler and an upper portion of snow deposited on the bottom plate by using an image capturing device, a measurement unit configured to measure the amount of snowfall based on information on the captured image, and a movement unit configured to move the device for measuring the amount of snowfall so that a position of the bottom plate moves from a first position to a second position.

Abstract: A method for forming in particular reflection-reducing nanostructures (5) on a preferably polished surface (3) of a crystalline, in particular ionic, substrate (1) for transmission of radiation in the FUV/VUV wavelength range. The method includes: providing a surface (3, 7), which surface is not oriented along a lattice plane having a minimum surface energy, on the substrate (1) or on a layer (6) applied to the substrate (1) by a coating method, in particular vacuum vapor deposition, and introducing an energy input (E) into the surface (7) for rearranging the surface (7) to form the nanostructures (5), wherein the energy input (E) is generated by irradiating the surface (7) with electromagnetic radiation (4). Also, an optical element for transmission of radiation in the FUV/VUV wavelength range.

Abstract: An optical lens assembly including a first lens element, a second lens element and a third lens element is provided. A periphery region of a light incident surface of the first lens element is concave. The second lens element has positive refracting power, and an optical axis region of a light incident surface of the second lens element is concave. A periphery region of a light exit surface of the third lens element is concave, and an optical axis region of a light incident surface of the third lens element is convex. The lens elements of the optical lens assembly only include the first lens element to the third lens element, and a thickness of the first lens element along an optical axis is greater than or equal to a sum of two air gaps from the first lens element to the third lens element along the optical axis.

Abstract: The present disclosure discloses an optical imaging system including, sequentially from an object side to an image side along an optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. Each of the first lens to seventh lens has refractive power. An object-side surface of the first lens is concave, and an image-side surface thereof is concave; an object-side surface of the second lens is convex, and an image-side surface thereof is convex; and an object-side surface of the third lens is concave, and an image-side surface thereof is convex. An effective focal length f4 of the fourth lens and a total effective focal length f of the optical imaging system satisfy ?2.0<f4/f<?1.5. Half of a maximal field-of-view Semi-FOV of the optical imaging system satisfies Semi-FOV?55°.

Abstract: A photographing optical lens assembly includes seven lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The first lens element has negative refractive power. The third lens element has positive refractive power. The fourth lens element has negative refractive power. The sixth lens element has an image-side surface being convex in a paraxial region thereof. The seventh lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The image-side surface of the seventh lens element has at least one critical point in an off-axis region thereof. There is an air gap in a paraxial region between all adjacent lens elements of the seven lens elements.

Abstract: The present disclosure discloses a camera lens assembly including, sequentially from an object side to an image side along an optical axis, a first lens having refractive power; a second lens having positive refractive power and a convex image-side surface; a third lens having negative refractive power, a convex object-side surface and a concave image-side surface; a fourth lens having negative refractive power; a fifth lens having refractive power and a convex image-side surface; and a sixth lens having refractive power, a convex object-side surface and a concave image-side surface. Half of a maximum field-of-view Semi-FOV of the camera lens assembly and a combined focal length f23 of the second lens and the third lens satisfy: 4.00 mm<tan2(Semi-FOV)*f23<10.00 mm.

Abstract: A lens module includes a first lens, a second lens, and a third lens comprising a convex object-side surface and a convex image-side surface. The lens module also includes a fourth lens including a concave object-side surface and a concave image-side surface, a fifth lens including a concave object-side surface, and a sixth lens including an inflection point formed on an image-side surface thereof. The first to sixth lenses are sequentially disposed from an object side to an image side.

Abstract: An optical photographing system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element has an image-side surface being convex in a paraxial region thereof. The third lens element has positive refractive power. The fourth lens element has an object-side surface being concave in a paraxial region thereof. The fifth lens element with positive refractive power has two surfaces being both aspheric. The sixth lens element has an image-side surface being concave in a paraxial region thereof, wherein the surfaces of the sixth lens element are both aspheric, and the image-side surface of the sixth lens element includes at least one convex shape in an off-axial region thereof.

Abstract: An optical imaging lens may include a first, a second, a third, a fourth, a fifth, a sixth, a seventh, and an eighth lens elements positioned in an order from an object side to an image side. Through designing concave and/or convex surfaces of each lens elements, the optical imaging lens may provide improved imaging quality and optical characteristics, reduced length of the optical imaging lens and increased field of view while the optical imaging lens may satisfy at least one inequality.

Abstract: Zoom digital cameras comprising a Wide sub-camera and a folded fixed Tele sub-camera. The folded Tele sub-camera may be auto-focused by moving either its lens or a reflecting element inserted in an optical path between its lens and a respective image sensor. The folded Tele sub-camera is configured to have a low profile to enable its integration within a portable electronic device.

Abstract: Aspect ratio modifying imaging systems and methods are provided. In one example, an infrared imaging device includes at least one lens element configured to transmit electromagnetic radiation associated with a portion of a scene. The portion has a first aspect ratio. The electromagnetic radiation includes mid-wave and/or long-wave infrared light. The at least one lens element has a freeform surface having no translational symmetry and no rotational symmetry. The infrared imaging device further includes a detector array configured to receive image data associated with the electromagnetic radiation from the at least one lens element and generate, based on the image data, an image. The image data has a second aspect ratio different from the first aspect ratio. Each of the first and second aspect ratios is a ratio of a size along a first direction and a size along a second direction orthogonal to the first direction.

Abstract: A projection lens includes a first lens group, a second lens group and an aperture stop. The first lens group is disposed between a reduced side and a magnified side. The second lens is disposed between the first lens group and the magnified side. The second lens group has a light incident surface, a reflective surface and a light emitting surface, the light incident surface faces the first lens group, the light emitting surface faces a projection surface, the light incident surface, the light emitting surface and the first lens group are disposed at a single side of the reflective surface, and at least one of the light incident surface, the reflective surface and the light emitting surface is a freeform surface. The aperture stop is disposed between the first lens group and the second lens group. Moreover, a projection apparatus including the projection lens is also provided.

Abstract: A zoom relay system includes an optical element for receiving light from an object. The zoom relay system is adapted to generate an image of the object on an image plane. The system includes a single varifocal lens group positioned along an optical axis. The varifocal lens group includes at least one lens for providing magnification and a varifocal freeform lens including two lens plates. The lens plates are configured to be disposed along a dimension transverse to the optical axis, such that, when the varifocal lens group is moved along the optical axis to adjust the magnification, the lens plates of the varifocal freeform lens are displaced in the transverse dimension relative to each other to provide compensation, such that, when the magnification is changed, a distance between the object and the image plane remains constant.

Abstract: An optical system internally has an intermediate imaging position that is conjugated to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, respectively. The optical system includes a magnification optical system having a first lens element and a second lens element positioned on the magnification side with respect to the intermediate imaging position; and a relay optical system having a plurality of lens elements, positioned on the reduction side with respect to the intermediate imaging position. The first lens element and the second lens element are positioned in this order from the magnification side, and the second lens element has a positive power. The optical system satisfies: 23<|f2/fw|<1000, wherein f2 is a focal length of the second lens element, and fw is a focal length of an entirety of the optical system at a wide-angle end.

Abstract: Disclosed herein are device and method for performing a total internal reflection scattering (TIRS) measurement to a sample slide. The device comprises a first reflective plate having a first opening; a second reflective plate having second and third openings and disposed on top of the first reflective plate thereby forming a slot therebetween for accommodating the sample slide, wherein the first opening of the first reflective plate is disposed directly underneath the second opening of the second reflective plate; a white light source disposed in the space formed by the third opening of the second reflective plate and configured to emit a white light into the slot; and a first blackout layer disposed on top of the third opening thereby covering the white light source and keeping the emitted white light from leaking. When the sample slide is inserted into the slot, the white light source illuminates the sample slide so as to achieve the TIRS measurement to the sample slide.