Abstract: A LIDAR unit includes a housing defining a cavity. The LIDAR unit further include a plurality of emitters disposed on a circuit board within the cavity. Each of the emitters emits a laser beam along a transmit path. The LIDAR system further includes a first telecentric lens assembly positioned within the cavity and along the transmit path such that the laser beam emitted from each of the plurality of emitters passes through the first telecentric lens assembly. The LIDAR further includes a second telecentric lens assembly positioned within the cavity and along a receive path such that a plurality of reflected laser beams entering the cavity pass through the second telecentric lens assembly. The first telecentric lens assembly and the second telecentric lens assembly each include a field flattening lens and at least one other lens.

Abstract: Provided is a technique capable of moving a mobile body to an appropriate position and eliminating the mobile body. This mobile body control system is provided with: a false signal generation unit that generates a false signal for calculating a position different from the actual position of the mobile body on the basis of signal code information which the mobile body has received to calculate the position thereof; and a false signal transmission unit that transmits the generated false signal into a prescribed region.

Abstract: A system and method for determining a GNSS receiver position includes receiving a first and a second set of satellite observations; determining a first and second ambiguity set associated with a first and second transformation respectively; determining cross-validated ambiguities between the first and second ambiguity sets; and determining the GNSS receiver position based on at least one of the first or second ambiguity sets.

Abstract: The presence or absence of a preamble is detected with accuracy in a reception apparatus that receives a signal including a preamble. A reception section receives a subframe including a subframe preamble and a message and a frame including a frame preamble. A processing section performs a process of detecting the presence or absence of the subframe preamble according to whether or not a given relation holds between a reception timing of the subframe preamble and a reception timing of the frame preamble. A message decoding section extracts the message from the subframe and decodes the message in a case where the presence of the subframe preamble is detected.

Abstract: A ground antenna determines the current time and its own position from received signals that were transmitted by artificial earth satellites for communication. A high-gain multi-beam electrically-steered antenna is combined with a processing system to measure the angles between two or more satellites and determine the present distance to each satellite by the information broadcast on the TT&C channel. The knowledge of the angles and distances, as well as the trajectory of the satellites, can be combined with their locations as predicted by the satellite ephemeris data to triangulate the location of the receiver. This system is different from conventional GPS antennas because it does not require the cooperation of active communication with the satellites to derive a location estimate. The location is computed by the ground terminal, not by the satellite.

Abstract: Disclosed herein are methods, systems, and devices for monitoring cumulative radiation. In one embodiment, a device includes a photodiode; an integrating capacitor electrically coupled with the photodiode; a voltage discharge switch electrically coupled with the integrating capacitor; and amplifier circuitry electrically coupled with the photodiode and the integrating capacitor. The amplifier circuitry is configured to maintain a substantially zero bias voltage between an anode and a cathode of the photodiode monitoring the cumulative radiation. The integrating capacitor is configured to provide a delta voltage representative of radiation received since the beginning of a charge cycle of the integrating capacitor.

Abstract: A position-signal processing method for flat panel gamma imaging probe includes a modeling phase and a use phase. In the modeling phase, a weight direction for an imaging detector is defined, position centers and weight ratios of the imaging detector in the weight direction are utilized to obtain a distribution graph of the weight ratios to the position centers, and curve fitting is performed upon the distribution graph to obtain a position estimation curve. In the use phase, the position estimation curve is utilized to derive a position estimation value of a probe trigger event in a 2D crystal diagram, a position value of the probe in the 2D crystal diagram with respect to the position estimation value of the probe trigger event is obtained, and a crystal code is located in a crystal code look-up table for the position value of the probe in the 2D crystal diagram.

Abstract: A radiation detector includes a photodetector and a scintillator coupled thereto. The scintillator is formed of a scintillator material comprising an organic glass scintillator (OGS) material and at least one of a polymer additive or a plasticizer additive. The scintillator emits light when radiation is received at the scintillator, and the light is received by the photodetector. The radiation detector can further include a frame that has an interior cavity that holds the scintillator in position with respect to the photodetector, such that the light emitted by the scintillator is transmitted to the photodetector. The scintillator can be formed by casting amorphous scintillator material in the interior cavity of the frame. The frame can then be coupled to the photodetector to form the radiation detector.

Abstract: An X ray device, including an array substrate, a scintillator layer, a first adhesion layer, a function film, and a second adhesion layer, is provided. The scintillator layer is disposed on the array substrate. The first adhesion layer is disposed between the scintillator layer and the array substrate. The function film is disposed on the array substrate. The second adhesion layer is disposed between the function film and the array substrate. The function film covers the scintillator layer.

Abstract: An X-ray device, including a sensor panel and a flexible scintillator structure disposed on the sensor panel, is provided. A manufacturing method of the X-ray device is also provided.

Abstract: According to one embodiment, a radiation detector includes first and second resin members, a detection part, a wiring part, and a controller. The first resin member includes first and second partial regions, and a third partial region between the first and second partial regions. The second resin member includes fourth and fifth partial regions. The detection part is provided between the first and fourth partial regions. The detection part includes a first conductive layer, a second conductive layer provided between the first conductive layer and the fourth partial region, and an organic semiconductor layer provided between the first and second conductive layers. The wiring part is provided between the third and fifth partial regions. The wiring part includes first and second wiring layers. The controller is fixed to the second partial region. The controller is electrically connected with the first and second wiring layers.

Abstract: A radiation detector includes a p-i-n architecture including a p-type contact layer, an n-type contact layer, and an intrinsic layer between the p-type contact layer and the n-type contact layer. The intrinsic layer includes a thin film comprising a highly crystalline 2D layered perovskite material. The radiation detectors according to embodiments of the present disclosure generate high open circuit voltages, have good detecting photon density limits and high sensitivities, and can be self-powered.

Abstract: Detection of nuclear reactions are accomplished through use of a solid-state detector that uses a hexagonal boron nitride configuration. Metallized areas for the hexagonal boron nitride have a metallized top and bottom area that is pixelated.

Abstract: An apparatus and method are described for capturing images in visible light as well as other radiation wavelengths. In one embodiment, the apparatus comprises: a diffraction coded imaging system including a plurality of apertures arranged in a diffraction coded array pattern with opaque material blocking array elements not containing apertures; and a light- or radiation-sensitive sensor coupled to the diffraction coded imaging system array and positioned at a specified distance behind the diffraction coded imaging system array, the radiation-sensitive sensor configured to sense light or radiation transmitted and diffracted through the apertures in the diffraction coded imaging system array.

Abstract: A system, a method and an autonomous network for vibration monitoring, the system comprising a master station preset for recording vibrations at a master trigger threshold; a secondary station, the secondary station and the master station being time synchronized, a server in communication with the master and secondary stations; wherein, the master station is configured to transmit a master trig time to the server and to start recording vibrations when the master trigger threshold is exceeded; the server is configured to store the master trig time; the secondary station is configured to detect the master trig time stored by the server, and upon detecting the master trig time, to record vibrations; and wherein the master and secondary stations are configured to transmit respective recorded vibrations to the server and the server is configured to classify the recorded vibrations in relation to a preset seismic threshold.

Abstract: A multi-function acquisition device comprising a connector having two connection terminals, and an electronic circuit that comprises an acquisition circuit configured for enabling the digital conversion of analogic signals from a sensor, and the memorization of the digitized signals in a memory; a harvesting circuit configured for enabling the transmission of data stored in the memory to a harvesting device; a charging circuit configured for enabling the charging of a battery with the power provided by a powering device. A control unit controls the activation of the acquisition circuit, the activation of the harvesting circuit, and the activation of the charging circuit.

Abstract: Disclosed are methods, systems, and computer-readable medium to perform operations including: receiving seismic data acquired by at least one receiver of a geologic survey system configured to perform a geologic survey of a subterranean formation, wherein the seismic data is associated with reflected acoustic signals generated by at least one source of the geologic survey system; calculating a ground force signal by stacking the acoustic signals generated by the least one source; calculating, using the ground force signal, a time and depth variant quality factor (Q) of the subterranean formation; and compensating, based on the time and depth variant Q, attenuation in the seismic data.

Abstract: A method and system for estimating a full elastic tensor. The method may comprise taking a measurement for compressional wave sonic data and cross-dipole shear data with a sonic logging tool at a first location as cross-dipole data, processing the compressional wave sonic data to produce a compressional wave slowness (P), and processing the cross-dipole shear data to produce a fast horizontal polarized shear wave slowness (SH) and a slow quazi-vertical shear wave slowness (qSV) as a function of depth. The method may further comprise setting an initial guess for at least five constants of the full elastic tensor for Vertical Transversely Isotropy (VTI) symmetry, determining a modeled slowness surfaces from the full elastic tensor, and comparing the modeled slowness surfaces with measured values of the P, the SH, and the qSV. The method may be performed by a system comprising a sonic logging tool and an information handling system.

Abstract: A proximity sensor comprising: a loop comprising an outer surface and an inner surface, at least a portion of the inner surface being a reflective surface; a light emitter positioned to emit light onto the reflective surface; a light detector positioned to preferentially receive light emitted from the light emitter and reflected from the reflective surface; and a processor that is configured, responsive to a set of instructions stored in a memory, to determine a degree of proximity of an object to the inner surface of the loop responsive to a reduction in an intensity of light emitted from the light emitter that is received by the light detector.

Abstract: A separation assembly for use with handheld metal detectors. According to one aspect, the separation assembly is mounted to a handheld metal detector having a blade containing transmission and receiver components of the handheld metal detector. The separation assembly includes at least a first separation member formed of a nonferromagnetic material, and the first separation member is spaced a lateral separation distance from the blade of the handheld metal detector. The separation assembly may be incorporated as a permanent and integrated part of a handheld metal detector, or separately manufactured and installed on a handheld metal detector.

Abstract: An x-ray imaging apparatus includes an x-ray source module configured to output source x-rays, a pencil-beam-forming module having input and output ports, and a module engagement interface that enables a user to select aligned and non-aligned configurations of the source and pencil-beam-forming modules. In the aligned configuration, the pencil-beam-forming module is aligned with the source module to receive source x-rays at the input port and to output a scanning pencil beam through the output port toward a target. In the non-aligned configuration, the pencil-beam-forming module is not aligned with the x-ray source module to receive the source x-rays nor to output the pencil beam, but instead enables the source x-rays to form a stationary, wide-area beam directed toward the target. Example embodiments can be handheld, can enable both backscatter imaging and high-resolution transmission imaging using the same apparatus, and can be employed in finding and disarming explosive devices.

Abstract: In some embodiments, a method includes emitting, from a transmitter positioned in a wellbore formed in a subsurface formation, a pulse of neutrons into the subsurface formation and detecting gamma ray emissions at a near field and a far field generated in response to the pulse of neutrons being emitted into the subsurface formation. The method includes determining a single elemental decay for one chemical element of a number of chemical elements present in the subsurface formation based on the gamma ray emissions and determining at least one geophysical property of the subsurface formation based on the single elemental decay of the one chemical element.

Abstract: Systems and methods may utilize information collected by a pulsed-neutron logging tool along with modeling a characterization of a borehole to form a 3-stage correction algorithm. This algorithm may be used to find an oil, water, and gas holdup in the borehole. During operations, a pulsed neutron logging tool which emits neutrons to interact with nuclei inducing gamma radiation. The gamma radiation is detected into a response which may be correlated to the location of a holdup in a borehole by using the entire spectrum or ratios of selected peaks. In examples, a borehole density index may be implemented to complement the response and improve accuracy and measurement confidence.

Abstract: A power beaming system includes a power beam transmitter arranged to transmit the power beam, and a power beam receiver arranged to receive the power beam from the power beam transmitter. A power beam transmission source is arranged to generate a laser light beam for transmission by the power beam transmitter from a first location toward a remote second location. A beam-shaping element shapes the laser light beam, at least one diffusion element uniformly distributes light of the shaped laser light beam, and a projection element illuminates a power beam receiving element of predetermined shape with the shaped laser light beam. At the power beam receiver, a diffusion surface diffuses a portion the power beam specularly reflected from the power beam receiver.

Abstract: A method for ranking thermal reactivities for kinetics assignment in basin modeling may include obtaining information relating to various source rock samples. The method may include determining thermal reactivities of source rocks corresponding to the various source rock samples. The source rocks are at a same level of thermal maturity in an area of interest. The method may include ranking the thermal reactivities at different thermal maturities. The method includes comparing published, archived and measured kinetic parameters of source rocks in the area of interest. The method may include sorting kinetic parameters in organofacies of a source rock formation in terms of reactivity and maturity. The method may include assigning kinetic parameters derived from an immature source rock unit to mature source rock units in a source rock formation in a sedimentary basin. The method may include evaluating the reactivities to improve selection and assignment of the kinetic parameters in the basin modeling.

Abstract: Among other things, a dispensing device is described herein. A sensor component of the dispensing device includes an emitter (e.g., of an emitter array) in optical communication with a detector array for sensing objects disposed between the emitter and the detector array. An object detector is configured to identify a presence of an object between the emitter and the detector array based upon a readout signal generated by the detector array. A calibration component is configured to recalibrate the object detector responsive to determining that an obstruction is present between the emitter and the detector array. The recalibration allows the detector array and the emitter array to detect the presence of an object regardless of the obstruction. A material (e.g., soap, sanitizer, etc.) may be dispensed from the dispensing device responsive to detecting the presence of the object.

Abstract: Provided are methods, devices and non-transitory computer readable storage mediums to generate a more accurate weather forecast by utilizing actual observation of a weather event in a particular location and time. For example, the observation data may be received from a user device and contain information indicative of a weather event that the user observed. Alternatively, or additionally, the observation data may be automatically generated by one or more sensors placed in certain locations and transmitted to a central server automatically upon detecting an observation. The observation data may be used to predict a weather forecast of a location that corresponds to, or is otherwise related to the particular location in which the observed event occurred.

Abstract: Computerized method and system for estimating a rain attribute on microwave communications, the estimation being carried out by: obtaining quantized minimum and maximum levels of received signals and transmitted signals over a microwave link during a period; subtracting the quantized maximum level of received signals from the quantized minimum level of transmitted signals to provide a minimal attenuation value; subtracting the quantized minimal level of received signals from the quantized maximal level of transmitted signals to provide a maximal attenuation value; calculating an attenuation difference related to the period by subtracting the minimal attenuation value from the maximal attenuation value; calculating a bias compensated attenuation difference based on the attenuation difference, and bias value related to the microwave link; and calculating the rain attribute, including the average rain during the period, based on the bias compensated attenuation difference.

Abstract: Snow sensors, mechanisms, and methods for snow sensor reading, assemblies for use with snow sensors, such as snow removal systems and assemblies and related components, as well as component combinations and related methods.

Abstract: A sub-hogel configuration for a high-definition light field display that can be used in the design of optical device and three-dimensional light field display technology. Three-dimensional holographic pixels (hogels) composed of monochromatic sub-hogels and a designed metasurface act as a directional optical element for a light field display. The sub-hogel structure design and method is suited for an achromatic metasurface to provide directional pixels for multiple view light field colored displays.

Abstract: The present disclosure provides a structure having a low reflectance surface, wherein the structure comprises: a base plate; and a plurality of inclined rods protruding from a first face of the base plate and inclined relative to a normal line to the first face, wherein the inclined rods are spaced from each other. Travel paths of light beams in the structure may be longer along the inclined rods. As a result, a larger amount of light may be absorbed by the structure having a low reflectance surface. The amount of light-beams as reflected from the structure having a low reflectance surface may be significantly reduced.

Abstract: A surface treatment composition including a perfluoropolyether group-containing silane compound and a solvent, wherein a proportion of the perfluoropolyether group-containing silane compound based on a total amount of the perfluoropolyether group-containing silane compound and the solvent is in the range from 30 to 99% by mass.

Abstract: Disclosed herein is a lens comprising a central portion that comprises a first polymer; and a peripheral portion that comprises a second polymer; where the peripheral portion surrounds the central portion; and where the peripheral portion has a skeletal density that is greater than its bulk density. Disclosed herein too is a method of manufacturing a lens comprising injecting into a mold a molten polymer to produce the lens; where the lens comprises a central portion; and a peripheral portion; where the peripheral portion surrounds the central portion; and where the peripheral portion has a skeletal density that is greater than its bulk density.

Abstract: Systems and methods reduce temperature induced drift effects on a liquid lens used in a vision system. A feedback loop receives a temperature value from a temperature sensor, and based on the received temperature value, controls a power to the heating element based on a difference between the measured temperature of the liquid lens and a predetermined control temperature to maintain the temperature value within a predetermined control temperature range to reduce the effects of drift. A processor can also control a bias signal applied to the lens or a lens actuator to control temperature variations and the associated induced drift effects. An image sharpness can also be determined over a series of images, alone or in combination with controlling the temperature of the liquid lens, to adjust a focal distance of the lens.

Abstract: An imaging lens assembly includes a dual molded optical element, a plurality of imaging lens elements and a light blocking element. The dual molded optical element has an object-side surface and an image-side surface and includes a light transmitting portion and a light absorbing portion. The light transmitting portion includes an optical effective section. The light absorbing portion is located on at least one of the object-side surface and the image-side surface of the dual molded optical element, and a plastic material of the light absorbing portion and a plastic material of the light transmitting portion are different colors. The imaging lens elements are disposed in the inner space of the imaging lens assembly. The light blocking element is disposed adjacent to the light transmitting portion of the dual molded optical element.

Abstract: Embodiments of the present disclosure relate to methods for fabricating optical devices. One embodiment of the method includes disposing a structure material layer on a surface of a substrate and disposing a patterned photoresist over the structure material layer. The patterned photoresist has at least one device portion and at least one auxiliary portion. Each device portion and each auxiliary portion exposes unmasked portions of the structure material layer. The unmasked portions of structure material layer corresponding to each device portion and each auxiliary portion are etched. The etching the unmasked portions forms at least one optical device having device structures corresponding to the unmasked portions of at least one device portion and at least one auxiliary region having auxiliary structures corresponding to the unmasked portions of at least one auxiliary portion.

Abstract: A polarization-based generator of duality modulated electromagnetic radiation, and a related method, by which the duality ratio of the energy-based irradiance and wave-based intensity may be selectively altered. A linearly polarized coherent radiation beam is incident on a polarizer configuration. Relative angular alignment of the beam's polarization and the polarizer configuration selectively provides output beams ranging from totally energy-depleted radiation to significantly energy-enriched radiation.

Abstract: A polarizing plate and an optical display apparatus are provided. A polarizing plate includes: a polarizer; and a first retardation layer and a second retardation layer sequentially stacked on a lower surface of the polarizer, and the first retardation layer has a short wavelength dispersion of about 1 to about 1.03, a long wavelength dispersion of about 0.98 to about 1, and an in-plane retardation of about 180 nm to about 220 nm at a wavelength of 550 nm, the second retardation layer has a short wavelength dispersion of about 1 to about 1.1, a long wavelength dispersion of about 0.96 to about 1, and an in-plane retardation Re of about 70 nm to about 120 nm at a wavelength of 550 nm, and a ratio of out-of-plane retardation of the second retardation layer at a wavelength of 550 nm to thickness thereof is about ?33 nm/?m to about ?15 nm/?m.

Abstract: A display device includes an electronic part, a support part including a through hole overlapping the electronic part, a display part disposed above the support part and including a first area overlapping the through hole, and a second area non-overlapping the through hole, the second area being adjacent to the first area, a polarizing plate disposed above the display part and having a transmission axis parallel to a direction, and a pattern optical layer disposed on the polarizing plate and including first phase retardation parts having a first optical axis, and second phase retardation parts having a second optical axis orthogonal to the first optical axis.

Abstract: A light source module includes at least one light-emitting element, a first optical layer, a penetrating light selection layer, a second optical layer, a light splitting layer, and a wavelength conversion layer. The light-emitting element is configured to provide a beam with a wavelength falling within a first wavelength band. An exit angle at which the beam exits the first optical layer is greater than an incident angle at which the beam is incident to the first optical layer. The penetrating light selection layer may allow light with a wavelength falls within a second wavelength band to pass through and has corresponding transmittance for light with a wavelength falling within the first wavelength band and is incident at different incident angles. An exit angle at which the beam exits the second optical layer is less than an incident angle at which the beam is incident to the second optical layer.

Abstract: The present disclosure discloses a lighting device and a lamp apparatus. The lighting device includes a light source supply assembly and a curved light guide element. The light source supply assembly includes a fixing base and a light source module. The fixing base has two opposite first accommodating areas, and the light source module is disposed in at least one of the two first accommodating areas, two ends of the curved light guide element are inserted into the two first accommodating areas, and one end of the curved light guide element corresponding to the light source module has a light source introduction bump, the light source introduction bump has a light incident surface corresponding to the light source module, the light source module supplies a light source, the light source enters from the light incident surface and propagates along the curved light guide element.

Abstract: An optical film is disclosed. The optical film is divided into a main body and two extending portions arranged along a second direction by two imaginary lines which are extended along a first direction and parallel to each other, wherein the second direction is substantially perpendicular to the first direction. The main body is located between the two extending portions. Each of the extending portions has an abutting edge. A first length W0 of the main body along the first direction is greater than a second length W1 of the abutting edge along the first direction.

Abstract: A light emitting module includes a light guide plate including a first face, a second face opposing the first face, and a through part penetrating between the first face and the second face, a light emitting device disposed in the through part on a second face side, a light transmissive member disposed on the light emitting device in the through hole on a first face side and between the light emitting device and a lateral wall of the through part, and a first light reflecting member disposed between an upper face of the light emitting device and the light transmissive member while being in contact with the upper face of the light emitting device.

Abstract: Disclosed embodiments include an energy directing device having one or more energy relay elements configured to direct energy from one or more energy locations through the device. In an embodiment, surfaces of the one or more energy relay elements may form a singular seamless energy surface where a separation between adjacent energy relay element surfaces is less than a minimum perceptible contour. In disclosed embodiments, energy is produced at energy locations having an active energy surface and a mechanical envelope. In an embodiment, the energy directing device is configured to relay energy from the energy locations through the singular seamless energy surface while minimizing separation between energy locations due to their mechanical envelope. In embodiments, the energy relay elements may comprise energy relays utilizing transverse Anderson localization phenomena.

Abstract: Disclosed embodiments include an energy waveguide system having an array of waveguides and an energy inhibiting element configured to substantially fill a waveguide element aperture and selectively propagate energy along some energy propagation paths through the array of waveguides. In an embodiment, such an energy waveguide system may define energy propagation paths through the array of waveguides in accordance to a 4D plenoptic system. In an embodiment, energy propagating through the energy waveguide system may comprise energy propagation for stimulation of any sensory receptor response including visual, auditory, somatosensory systems, and the waveguides may be incorporated into a holographic display or an aggregated bidirectional seamless energy surface capable of both receiving and emitting two-dimensional, light field or holographic energy through waveguiding or other 4D plenoptic functions prescribing energy convergence within a viewing volume.

Abstract: An optical probe imaging system includes an optical probe having a multicore optical fiber. Distal optics image light propagating in the multicore optical fiber so as to generate a light pattern on a sample that is based on a relative position of the cores. A distal motor causes the light pattern to traverse a path across the sample. An optical receiver includes a first receiver receiving light that has traversed the path across the sample from one of the at least two cores and a second receiver receiving light that has traversed the path across the sample from the other of the cores, such that the first receiver and the second receiver detect light in parallel. A processor maps relative position of the cores at the distal facet based on signals generated by the receiver.

Abstract: Optical fiber filters and uses thereof are presented. In typical implementations, there is provided a FBG taking deleterious light out of a fiber core without reflecting it into the fiber core. It also allows the unhindered transmission of useful light at a wavelength outside of the spectral band covered by the deleterious light. The filter couples the incoming deleterious light to cladding modes propagating in the opposite direction without coupling the incoming useful light to core or cladding modes propagating in the opposite direction. The filter may for example be useful as a Raman or ASE filter in a laser cavity of other optical devices.

Abstract: Disclosed is a Chinese knot-like porous fiber core ultra-high birefringence THz optical fiber. The optical fiber comprises a substrate, claddings and fiber cores, wherein the claddings and the fiber cores are arranged in the substrate, and the fiber cores are embedded in the centers of the claddings; and the fiber core comprises a first fiber core region, a second fiber core region and a third fiber core region, the center of the first fiber core region 4 serves as the origin of coordinates, and the first fiber core region 4 is composed of six regular hexagon units with overlapped boundaries in the x-axis direction. In the present disclosure, the fiber core comprises a first fiber core region, a second fiber core region and a third fiber core region, and the three regions jointly form a fiber core region of a Chinese knot-like porous fiber core.

Abstract: A method of forming a tapered tip of a polarization-maintaining (PM) fiber includes inserting a tip of the PM fiber into a first etchant solution characterized by a first etching rate for the core of the PM fiber and a second etching rate for the stress members of the PM fiber, the second etching rate being lower than the first etching rate, withdrawing the tip of the PM fiber from the first etchant solution at a withdrawal rate, immersing the tip of the PM fiber in a second etchant solution for a time duration. The second etchant solution is characterized by a third etching rate for the core and a fourth etching rate for the stress members, the fourth etching rate being greater than the third etching rate. The method further includes withdrawing the tip of the PM fiber from the second etchant solution.

Abstract: Embodiments of the current disclosure include low moat volume single mode ultra-low loss optical fibers. In some embodiments, a single mode optical fiber includes a first core region; a second core region surrounding and directly adjacent to the first core region, wherein a volume V of the second core region is less than or equal to 14% ??m2; a cladding region surrounding the core region; and wherein the optical fiber has a cable cutoff of less than 1260 nm, a mode field diameter at 1310 nm of 8.6 microns to 9.7 microns, a mode field diameter at 1550 nm of 9.9 microns to 11 microns, and an attenuation at 1550 nm of less than or equal to 0.17 dB/km.