Abstract: An optical device may include a lens system. The optical device may include a first scanning component to receive an optical beam and to scan the lens system with the optical beam. The optical device may include a second scanning component to receive the optical beam from the lens system and to scan a field of view with the optical beam, where the lens system is positioned between the first scanning component and the second scanning component. The lens system may include a beam expander.

Abstract: A LIDAR device for a vehicle includes an integrated chip. The integrated chip includes a substrate layer, a cladding layer, a waveguide, a scattering array, and a reflector layer. The cladding layer is disposed on the substrate layer to form an interface with the substrate layer. The waveguide is disposed within the cladding layer and configured to route an infrared optical field. The scattering array is disposed within the cladding layer between the waveguide and the interface and perturbs the infrared optical field and scatters the infrared optical field into a first beam propagating toward a surface of the cladding layer and into a second beam propagating towards the interface. The reflector layer is disposed within the cladding layer between the waveguide and the surface of the cladding layer to reflect the first beam towards the interface.

Abstract: Embodiments of the disclosure provide an apparatus for emitting laser light and a system and method for detecting laser light returned from an object. The system includes a transmitter and a receiver. The transmitter includes one or more laser sources, at least one of the laser sources configured to provide a respective native laser beam having a wavelength above 1,100 nm. The transmitter also includes a wavelength converter configured to receive the native laser beams provided by the laser sources and convert the native laser beams into a converted laser beam having a wavelength below 1,100 nm. The transmitter further includes a scanner configured to emit the converted laser beam to the object in a first direction. The receiver is configured to detect a returned laser beam having a wavelength below 1,100 nm and returned from the object in a second direction.

Abstract: A distance information acquisition device includes: a light emitter which emits light according to an emission pulse indicating emission; a solid-state imaging element which performs exposure according to an exposure pulse indicating exposure; an emission/exposure controller which generates a timing signal indicating a plurality of pairs of the emission pulse and the exposure pulse having a time difference that is different in each of the plurality of pairs; and a multipath detector which obtains a sequence of received light signals from the solid-state imaging element by the emission and the exposure that correspond to each of the plurality of pairs, compares the obtained sequence of received light signals and reference data created in advance as a model of a sequence of received light signals in a multipath-free environment, and determines the presence or absence of multipath according to a difference in a comparison result.

Abstract: Methods, apparatus, and systems related to light detection and ranging (LIDAR) are described. In one example aspect, a LIDAR apparatus includes a light emitter configured to generate, according to a first electrical pulse signal, a pulse light signal. The first electrical pulse signal comprises a first set of non-uniformly spaced pulses. The apparatus includes a receiver configured to convert returned light signals from the object into electrical signals and a filtering subsystem in communication with the receiver, configured to receive the electrical signals from the receiver and remove a point from a set of points representing at least a partial surface of the object as noise by determining whether there is a coherence between the point and corresponding neighboring points of the point along at least a first direction and a second direction of the set of points.

Abstract: In one example, a LIDAR device includes a light sources that emits light and a transmit lens that directs the emitted light to illuminate a region of an environment with a field-of-view defined by the transmit lens. The LIDAR device also includes a receive lens that focuses at least a portion of incoming light propagating from the illuminated region of the environment along a predefined optical path. The LIDAR device also includes an array of light detectors positioned along the predefined optical path. The LIDAR device also includes an offset light detector positioned outside the predefined optical path. The LIDAR device also includes a controller that determines whether collected sensor data from the array of light detectors includes data associated with another light source different than the light source of the device based on output from the offset light detector.

Abstract: A method for detecting a degradation in a distance-measuring system (1.1), comprising the following method steps: transmitting a transmission signal (1.2), acquiring a received signal back-scattered from an object, determining the distance (a) from the object using the received signal, and determining a degree of degradation based on the determined distance (a) from the object and/or the received signal strength of the received signal.

Abstract: A sonar system includes a towfish comprising a first body linked to a second body, the first body being elongate along a longitudinal axis and comprising a plurality of acoustic transmitters distributed along the longitudinal axis, the sonar system comprising a cable linked to the second body and via which a surface carrier ship is intended to tow the towfish, the first body being mounted to pivot, with respect to the second body, about an axis of rotation so that, the first body can switch, by pivoting with respect to the second body about the axis of rotation, from an operational position to a capture position; the axis of rotation being substantially an axis of movement of the towfish, the longitudinal axis being substantially vertical in the operational position of the first body and being substantially horizontal in the capture position of the first body, when the towfish is totally submerged and towed by the carrier ship.

Abstract: The present technology relates to nanomaterials and methods of their use, and more specifically to methods and structures using nanomaterials to fiducially measure radiation dosing.

Abstract: An apparatus, system, and method for real-time dosimetry. An electron beam irradiation system includes one or more detectors. The detectors have coils that, when an electron travels by a sensor pad in the detector, the electron induces a current into the coils. The current is detected and the electron is counted. The number of electrons counted at the one or more detectors is compared to the number of electrons leaving an electron gun, giving a dosage of the workpiece being irradiated.

Abstract: Disclosed herein is a radiation detector, comprising a first pixel; a first reflector; and a first scintillator, wherein the first reflector is configured to guide essentially all photons emitted by the first scintillator into the first pixel. The first reflector is configured to reflect photons emitted by the first scintillator toward the first reflector. The first scintillator is essentially completely enclosed by the first reflector and the first pixel.

Abstract: Disclosed herein is a method of recovering performance of a radiation detector, the radiation detector comprising: a radiation absorption layer configured to absorb radiation particles incident thereon and generate an electrical signal based on the radiation particles; an electronic system configured to process the electrical signal, the electronic system comprising a transistor, the transistor comprising a gate insulator with positive charge carriers accumulated therein due to exposure of the gate insulator to radiation; the method comprising: removing the positive charge carriers from the gate insulator by establishing an electric field across the gate insulator.

Abstract: A seismic observation device includes an input unit receiving input of time-series data of measurement values of a vibration, a processing target determination unit determining a time period of the time-series data that is a processing target, and a type determination unit acquiring a likelihood of classifying a cause of the vibration indicated in the time-series data in the time period into each of types of cause.

Abstract: A method for generating a geophysical image of a subsurface region includes defining a computational sub-volume for the geophysical image including a predetermined number of seismic traces of a plurality of seismic traces and a predetermined number of samples per each one of the plurality of seismic traces, generating a data matrix corresponding to a first sub-volume of the subsurface region based on the defined computational sub-volume, the data matrix comprising the predetermined number of samples for the predetermined number of traces of a portion of a seismic dataset corresponding to the first sub-volume. The method also includes estimating a coherence between the predetermined number of traces of the data matrix by performing a sum of a variance of the predetermined number of samples of the data matrix, and assigning the estimated coherence to a location in the geophysical image.

Abstract: A method for determining an internal multiple attenuated seismic image is disclosed. The method includes obtaining a seismic dataset composed of a plurality of seismic traces and for each seismic trace determining an internal multiple trace based, at least in part, on a nested truncated correlation and a bounded convolution of the seismic trace with itself. The method further includes determining an internal multiple attenuated seismic trace based, at least in part, on subtracting the internal multiple trace from the seismic trace and combining the internal multiple attenuated seismic trace to form the internal multiple attenuated seismic image. A system including a seismic source, a plurality of seismic receivers, and a seismic processor for executing the method is disclosed.

Abstract: A submersible node and a method and system for using the node to acquire data, including seismic data is disclosed. The node incorporates a buoyancy system to provide propulsion for the node between respective landed locations by varying the buoyancy between positive and negative. A first acoustic positioning system is used to facilitate positioning of a node when landing and a second acoustic positioning system is used to facilitate a node transiting between respective target landed locations.

Abstract: A wellbore system includes a logging unit having a retrievable logging cable coupled to a downhole tool within a wellbore and a depth correlation unit in the downhole tool that provides current depth data for the wellbore through the retrievable logging cable for recording of a current depth by the logging unit. The wellbore system also includes a distributed acoustic sensing unit that includes a seismic processing unit and a seismic profiling unit connected to a separate optical cable of the retrievable logging cable having distributed acoustic sensing channels, wherein an assignment of the distributed acoustic sensing channels along the separate optical cable is determined by an offset distance between the current depth of a formation reference region within the wellbore and a previous reference depth of the formation reference region within the wellbore. A distributed acoustic sensing method is also included.

Abstract: A method for correlating data comprises acquiring a first sequence signal and a second sequence signal, wherein the first sequence signal comprises at least a first data point including a first set of components and the second sequence signal comprises at least a second data point including a second set of components; acquiring a first set of user picks and a second set of user picks, wherein the first and the second sets of user picks each contain a respective first and second correspondence between a component in the first set of components and a component in the second set of components; combining the first and second sets of user picks with the first and second sequence signals to create a first hyper-complex signal and a second hyper-complex signal; and performing signal alignment on the first and second hyper-complex signals.

Abstract: A carrier for installing an RFID tag in a utility marker tube provides a centering plate fitting against an upper edge of the tube and oriented and positioned either by inner tube walls and/or the outer tube wall periphery to locate a downwardly extending transducer support tab holding the transducer within the tube. The centering plate may be held in place by a separate or integrated cap retaining the centering plate while sealing the tube against environmental contamination.

Abstract: Discriminating between a cable locating signal and a false cable locating signal is described. A reference signal, which contains a locating signal frequency impressed on it, is transmitted in a way which provides for detection of a phase shift between the locating signal and the false locating signal. Based on the phase shift, a receiver is used to distinguish the locating signal from the false locating signal.

Abstract: The present invention relates to a system for detecting illicit objects contained in a piece of luggage, characterized in that it comprises a carriage defining a housing (60) for receiving a piece of luggage and examination means (100, 200, 300) placed at the inlet of the housing (60) such that the introduction of the piece of luggage into the housing (60) induces a relative displacement between the piece of luggage and at least one of the examination means (200) and thus an automatic scanning of the piece of luggage by the examination means (200).

Abstract: An underground investigation device includes a transmission unit configured to transmit a pulse wave, a reception unit configured to receive a reflected signal, a memory configured to store time waveform data of the reflected signal, a storage device having a larger capacity than a capacity of the memory, a control unit configured to transfer the time waveform data from the memory to the storage device, and a signal processing unit configured to generate underground investigation data based on the time waveform data in the storage device. The reception unit sets a measurement span for sampling the reflected signal by using, as a trigger, transmission of the pulse wave or reception of a reflected signal resulting from reflection by a ground surface, samples the reflected signal in the measurement span, and stores the time waveform data in the memory. The control unit transfers the time waveform data from the memory to the storage device after the measurement span.

Abstract: A method of determining wettability may include: measuring an electrical property of a drilling fluid; and correlating the electrical property to wettability.

Abstract: Hydrocarbon wells include a wellbore, a fracture that extends from the wellbore, and an electromagnetic contrast material positioned within the fracture. The hydrocarbon wells also include a downhole electromagnetic transmitter, which is configured to direct an electromagnetic probe signal incident upon the electromagnetic contrast material, and a downhole electromagnetic receiver, which is configured to receive an electromagnetic resultant signal from the electromagnetic contrast material. Methods for monitoring fracture morphology of a fracture that extends from a wellbore of a hydrocarbon well include flowing an electromagnetic contrast material into a fracture and generating an electromagnetic probe signal. The methods also include modifying the electromagnetic probe signal with the electromagnetic contrast material to generate an electromagnetic resultant signal. The methods further include receiving the electromagnetic resultant signal and determining the morphology of the fracture.

Abstract: In an embodiment, a method includes receiving a first measurement of gamma rays via a detector during a first period of time, receiving a second measurement of gamma rays via the detector during a second period of time, removing the second measurement from the first measurement to produce an inelastic spectrum, determining a spectral slope from the inelastic spectrum, determining a scaling factor based on the spectral slope, determining a spectral shape associated with the detector, determining a detector-induced spectrum by applying the scaling factor to the spectral shape, and removing the detector-induced spectrum from the inelastic spectrum to produce a clean inelastic spectrum.

Abstract: Embodiments of the present disclosure are directed towards a method for improving neutron interpretations in a subsurface formation. Embodiments may include estimating mineral concentrations and kerogen concentrations at one or more depths in the subsurface formation and determining kerogen properties at one or more depths in the subsurface formation. Embodiments may further include calculating mineral properties at one or more depths in the subsurface formation and calculating a neutron-based log response to a rock matrix based upon, at least in part, the kerogen properties and the mineral properties at one or more depths in the subsurface formation by subtracting.

Abstract: A nuclear logging tool has a housing, one or more neutron sources, one or more shields, and two or more detectors disposed about the housing. Each of the one or more neutron sources is configured to generate neutrons in pulses or continuously and each of the two or more detectors is operable to detect neutrons and gamma rays. The two or more detectors include a first detector disposed at a first distance from a first neutron source and a second detector disposed at a second distance from the first neutron source. The first distance is shorter than the second distance. The first distance and the second distance is measured in the longitudinal direction of the housing. Each shield is operable to absorb neutrons and gamma rays and is disposed inside the housing between one of the one or more neutron source and one of the one or more detectors.

Abstract: A gravimeter probe includes a spring structure, a proof mass, movable comb fingers, fixed comb fingers, and an outer frame. A fixed end of the spring structure is arranged on the outer frame and a free end thereof is connected to the proof mass. The movable comb fingers are arranged on upper and lower surfaces of the proof mass, and the fixed comb fingers are correspondingly arranged on the outer frame. Each of the movable comb fingers and the fixed comb fingers has a special-shaped comb finger structure. The special-shaped comb finger structure includes a comb finger bottom portion and a comb finger top portion, and the width of the comb finger bottom portion is smaller than the width of the comb finger top portion.

Abstract: A method to estimate a depth profile of a weathering layer in a subterranean formation of a field is disclosed. The method includes obtaining gravity survey data of the field, generating an equivalent source density profile based on the gravity survey data, wherein the equivalent source density profile describes a set of equivalent gravitational sources to substitute rock layers of the subterranean formation, generating an equivalent source gravity response based on the equivalent source density profile, wherein the equivalent source gravity response excludes a gravity contribution from the weathering layer, calculating a separated weathering layer gravity response based on a difference between the gravity survey data and the equivalent source gravity response, wherein the separated weathering layer gravity response corresponds to the gravity contribution from the weathering layer, and generating a modeled weathering layer depth profile based on the separated weathering layer gravity response.

Abstract: A method may include obtaining dielectric log data regarding a geological region of interest. The method may further include generating sponge core data of the geological region of interest using a neural network model and the dielectric log data. The neural network model may be trained using various dielectric logs from various well sources. The method may further include determining, using the sponge core data, an amount of hydrocarbons in the geological region of interest.

Abstract: Systems and methods for modeling petroleum reservoir properties using a gridless reservoir simulation model are provided. Data relating to geological properties of a reservoir formation is analyzed. A tiered hierarchy of geological elements within the reservoir formation is generated at different geological scales, based on the analysis. The geological elements at each of the different geological scales in the tiered hierarchy are categorized. Spatial boundaries between the categorized geological elements are defined for each of the geological scales in the tiered hierarchy. A scalable and updateable gridless model of the reservoir formation is generated, based on the spatial boundaries defined for at least one of the geological scales in the tiered hierarchy.

Abstract: A method may include obtaining grid model data for a geological region of interest and well data for various wells in the geological region of interest. A well among the wells may correspond to a simulated well network in a reservoir simulation. The method may further include determining, based on the grid model data and the well data, a first simulation solution for a first constraint rate equation decoupled from the simulated well network and using a first search method. The method may further include determining, based on the grid model data, the well data, and the first simulation solution, a second simulation solution for a second constraint rate equation coupled to the simulated well network and using a second search method. The method may further include performing, based on the grid model data, and the second simulation solution, the reservoir simulation.

Abstract: Techniques for creating a replacement for optical elements with diffractive planar components based on metasurfaces are provided. In one example, a substantially flat optical component for lensing incoming electromagnetic radiation having at least one wavelength and a first phase into outgoing electromagnetic radiation having a second phase is provided.

Abstract: An article that includes: an inorganic oxide substrate having opposing major surfaces; and an optical film structure disposed on a first major surface of the substrate, the optical film structure comprising one or more of a silicon-containing oxide, a silicon-containing nitride and a silicon-containing oxynitride and a physical thickness from about 50 nm to less than 500 nm. The article exhibits a hardness of 8 GPa or greater measured at an indentation depth of about 100 nm or a maximum hardness of 9 GPa or greater measured over an indentation depth range from about 100 nm to about 500 nm, the hardness and the maximum hardness measured by a Berkovich Indenter Hardness Test. Further, the article exhibits a single-side photopic average reflectance that is less than 1%.

Abstract: A substrate is provided with an abrasion resistance antireflection coating. The coated substrate includes a multilayer antireflection coating on at least one side. The coating has layers with different refractive indices, wherein higher refractive index layers alternate with lower refractive index layers. The layers having a lower refractive index are formed of silicon oxide with a proportion of aluminum, with a ratio of the amounts of aluminum to silicon is greater than 0.05, preferably greater than 0.08, but with the amount of silicon predominant relative to the amount of aluminum. The layers having a higher refractive index include a silicide, an oxide, or a nitride.

Abstract: Anti-reflective article includes a layer defining an anti-reflective surface. The anti-reflective surface includes a series of alternating micro-peaks and micro-spaces extending along an axis. The surface also includes a series of nano-peaks extending along an axis. The nano-peaks are disposed at least on the micro-spaces and, optionally, the micro-peaks. The article may be disposed on a photovoltaic module or skylight to reduce reflections and resist the collection of dust and dirt.

Abstract: An anti-glare film is prepared which have a ratio R/V of a scattered specular reflection intensity R to a total V of scattered reflection intensity being from 0.01 to 0.12 and an absolute value of a chromaticity b* of transmitted light being 3 or less. The anti-glare film includes a transparent substrate layer, and an anti-glare layer formed on at least one surface of the transparent substrate layer. The anti-glare layer may be a cured product of a curable composition including one or more types of a polymer component and one or more types of a curable resin precursor component, and in particular, at least two components selected from a polymer component and a curable resin precursor component can be phase separated through liquid phase spinodal decomposition. This anti-glare film can achieve non-coloring properties and anti-glare properties in a compatible manner.

Abstract: A camera optical lens is provided. The camera optical lens includes, from an object side to an image side, a first lens, a second lens having a positive refractive power, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens. The camera optical lens satisfies following conditions: 1.80?f1/f?3.20; and 1.50?d11/d12?8.00, where f1 denotes a focal length of the first lens, d11 denotes an on-axis thickness of the sixth lens, and d12 denotes an on-axis distance from an image side surface of the sixth lens to an object side surface of the seventh lens. The camera optical lens according to the present disclosure meets design requirements for large aperture, wide angle and ultra-thinness while achieving good optical performance.

Abstract: Disclosed is a camera optical lens, comprising, from an object side to an image side in sequence: a first lens having a negative refractive power; a second lens having a positive refractive power; a third lens having a positive refractive power; a fourth lens having a negative refractive power; a fifth lens having a positive refractive power; and a sixth lens having a negative refractive power; wherein, the camera optical lens satisfies: ?4.50?f1/f??2.20; 2.00?f2/f?5.50; ?20.00?(R3+R4)/(R3?R4)??2.50; and 3.00?d9/d10?10.00; where, f denotes a focus length of camera optical lens; f1 and f2 denote focus lengths of first and second lens respectively; d9 denotes an on-axis thickness of fifth lens; d10 denotes an on-axis distance from an image side surface of fifth lens to an object side surface of sixth lens; R3 and R4 denote central curvature radii of an object side surface and an object side surface of second lens respectively.

Abstract: There is provided an optical system including: a first lens having positive refractive power and having a convex object-side surface; a second lens having positive refractive power; a third lens having refractive power; a fourth lens having refractive power; a fifth lens having refractive power; a sixth lens having refractive power; and a seventh lens having negative refractive power and having a concave image-side surface, wherein the first to seventh lenses are sequentially disposed from an object side, whereby an aberration improvement effect may be increased and a high degree of resolution may be realized.

Abstract: An optical imaging system includes a first lens having an object-side surface that is convex; a second lens having a refractive power and a refractive index of 1.65 or more; a third lens having a refractive power; a fourth lens having a refractive power and an object-side surface that is convex; a fifth lens having a refractive power; a sixth lens having a positive refractive power; and a seventh lens having an object-side surface that is convex, wherein the first lens through the seventh lens are sequentially disposed in numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system, and two or more of the first lens and the third lens through the seventh lens have a refractive index of 1.6 or more.

Abstract: An imaging lens system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, sequentially disposed at intervals from an object side of the imaging lens system. The imaging lens system satisfies 1.5<Nd5<1.6, 30<V5<50, and TTL/2IH<0.730, where Nd5 is a refractive index of the fifth lens, V5 is an Abbe number of the fifth lens, TTL is a distance from an object side surface of the first lens to an imaging plane, and 21H is a diagonal length of the imaging plane.

Abstract: An optical imaging system includes a first lens having a positive refractive power and a concave object-side surface, a second lens having a positive refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, and a fifth lens having a positive refractive power and a concave image-side surface. The first through fifth lenses are sequentially disposed in ascending numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens having a negative refractive power, a fifth lens having a negative refractive power, a sixth lens, and a seventh lens having a positive refractive power. The first lens to seventh lens are sequentially disposed in a direction from an object side toward an imaging plane.

Abstract: An image capturing optical lens 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 with positive refractive power has a convex object-side surface. The second lens element has refractive power. The third lens element with refractive power has a concave image-side surface. The fourth lens element has refractive power, and at least one surface thereof is aspheric. The fifth lens element with negative refractive power has a concave object-side surface and a convex image-side surface, and the surfaces thereof are aspheric. The sixth lens element with refractive power has a convex object-side surface, and an image-side surface changing from concave at a paraxial region thereof to convex at a peripheral region thereof, and the surfaces are aspheric.

Abstract: An optical imaging system includes a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element from an object side to an image side in order along an optical axis. The first lens element to the fifth lens element each include an object-side surface and an image-side surface. The object-side surface of the second lens element has a convex portion in a vicinity of a periphery of the second lens element. The image-side surface of the third lens element has a convex portion in a vicinity of a periphery of the third lens element. The image-side surface of the fifth lens element has a concave portion in a vicinity of the optical axis, and the image-side surface of the fifth lens element has a convex portion in a vicinity of a periphery of the fifth lens element.

Abstract: A wide-angle optical system includes a pair of front side lens units, an optical member, and a pair of rear side lens units. Each of the pair of front side lens units has a negative refractive power. The optical member has a pair of inclined surfaces and a bottom surface, and the pair of inclined surfaces is disposed such that a line of intersection is formed on an object side. Each of the pair of rear side lens units includes a positive lens, and in the pair of rear side lens units, two axes of rotational symmetry are parallel. With respect to two light rays, intersection and reflection occur at the optical member, and the intersection and the reflection occur after the two light rays are transmitted through the pair of inclined surfaces and before two light rays are transmitted through the bottom surface.

Abstract: An optical fingerprint sensing module includes an image sensing device, a light source and a light shielding structure. The image sensing device is configured to sense light transmitted from a fingerprint of a finger on a display panel. The image sensing device includes a light sensing plane having a first geometric center. The light source includes a light emitting plane having a second geometric center. The first geometric center is separated from the second geometric center by a distance from 2 mm to 20 mm. The light shielding structure is disposed between the image sensing device and the light source. In examples, the optical fingerprint sensing module further includes a field angle controller to constrain light pass there through with a field angle of 5-60 degrees. A display device including an optical fingerprint sensing module is disclosed herein as well.

Abstract: A photographing optical lens assembly includes seven lens elements, which are, in order from an object side to an image side along an optical path: 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 with positive refractive power has an image-side surface being convex in a paraxial region thereof. The fifth lens element has an object-side surface being concave in a paraxial region thereof. The sixth lens element has an object-side surface being convex in a paraxial region thereof. The seventh lens element has an image-side surface being concave in a paraxial region thereof and having at least one convex critical point in an off-axis region thereof.

Abstract: An imaging lens consisting of, in order from an object side to an image side: a first lens group; a second lens group that has a positive refractive power; and a third lens group that has a negative refractive power, wherein the first lens group includes, successively in order from a position closest to the object side to the image side, two negative lenses and a positive lens, the second lens group includes a positive lens and a negative lens, during focusing from an object at infinity to a closest object, the first lens group remains stationary with respect to an image plane, and the second lens group moves along an optical axis, and assuming that a focal length of the first lens group is f1, and a focal length of the second lens group is f2, Conditional Expression (1) is satisfied: ?0.5<f2/f1<0.5 (1).