Abstract: A large-scale and high-precision absolute distance measurement system based on an all-fiber femtosecond laser, including: a first all-fiber femtosecond laser, a second all-fiber femtosecond laser, a fiber optic splitter, a first fiber optic circulator, a wavelength division multiplexer, an achromatic fiber collimator, a first fiber optic combiner, a second fiber optic combiner, a second fiber optic circulator, a semiconductor laser, a first photodetector, a second photodetector, and a data acquisition and processing module.

Abstract: A method for Time-of-Flight (ToF) sensing of a scene is provided. The method includes performing, by a ToF sensor, a plurality of first ToF measurements using a first modulation frequency to obtain first measurement values. A respective correlation function of each of the plurality of first ToF measurements is periodic and exhibits an increasing amplitude over distance within a measurement range of the ToF sensor. The method additionally includes determining a distance to an object in the scene based on the first measurement values.

Abstract: A pulsed optical beacon source is formed of a fiber-based amplifier including a preamplifer stage (responsive to a CW seed laser source) and a booster stage coupled to the output of the preamplifier stage. The pump input to at least one stage is pulsed and controlled in a manner that allows for the formation of a pulsed beacon output that is able to perform the PAT requirements of a beacon source, while also allowing for a low bit rate (e.g., a few Hz to a few kHz) upstream data signal to be sent between the beacon source and a target's optical receiver.

Abstract: The present disclosure is related to field of Fiber Feedback (FFB) technology, and provides a method and system for estimating the distance between a fiber end and a target. The method includes illuminating, by a Light Emitting, Transmitting and Detecting (LETD) system, the target with laser light of different wavelengths having low and high water absorption coefficients, using different laser light sources, as well as receiving a returned signal corresponding to the incident laser light of different wavelengths, and detecting the returned signal to measure intensity values of the returned signal of a specific wavelength. Using the measured intensity values, a processing unit may estimate distance between the fiber end and the target. The present disclosure enables accurate estimation of distance between a fiber end and the target. The present disclosure also provides a robust distance estimation technique which is compatible with different types of targets.

Abstract: A fiber support assembly includes: a first glass tube, wherein the first glass tube is attached to a microlens or lenslet of a microlens or lenslet array; a second glass tube at least partially disposed within the first glass tube; and a gain fiber disposed within the second glass tube, wherein the gain fiber has a first tapered end cap, and wherein the gain fiber with the first tapered end cap is aligned to the microlens or lenslet attached to the first glass tube. The fiber support assembly may further include: a pump fiber disposed within the second glass tube, wherein the pump fiber has a second tapered end cap; and a reflector configured to receive counter-pumping light from the pump fiber and direct the counter-pumping light to the first tapered end cap of the gain fiber.

Abstract: A counter high-energy laser system directs high-intensity laser radiation back to a threat laser in the form of an ultra-short optical pulse (USP). The retro-directed USP induces permanent internal optical damage in the threat laser, thus disabling the threat by exploiting the very high optical gain at the source of an incoming laser thereby causing an injected pulse to grow exponentially in energy and peak power within the threat laser optical train until it reaches a damaging threshold. The existing optical energy from the threat laser system and stored in the laser beam from threat system is exploited thereby enabling the size, weight, and power of the counter laser system to be significantly reduced. The wavelength of the counter pulse is automatically matched to the threat.

Abstract: LIDAR systems and methods of calibrating the LIDAR systems. The LIDAR system has a light source, a scanning unit, and a detection unit. The scanning unit has a first reflective component for redirecting a light beam from the light source, a second actuatable reflective component for redirecting the light beam from the first reflective component towards the environment, and an adjustment mechanism for adjusting a position of the first reflective component relatively to the second reflective component along two degrees of freedom. The method includes emitting a light beam towards the first reflective component, actuating the first and second reflective components amongst a first and second plurality of positions respectively, detecting a self-flashing beam and, in response to the detecting the self-flashing beam, adjusting the position of the first reflective component relative to the second reflective component along at least one of the two degrees of freedom.

Abstract: Disclosed are a system and a method for configuring an optical transmission system. A process may include arranging a first ruggedized repeater on or in a first object or structure. A second ruggedized repeater may be arranged on or in a second object or structure different from the first object or structure. A third ruggedized repeater may be arranged on or in a third object or structure different from the first and second objects or structures, wherein: (i) a first distance between the first ruggedized repeater and the second ruggedized repeater and (ii) a second distance between the second ruggedized repeater and the third ruggedized repeater are equal or nearly equal and based on signal loss.

Abstract: An optoelectronic sensor includes a plurality of light sources for generating transmission light, including at least a first and a second light source. The optoelectronic sensor includes transmission optics for projecting transmission light into the field of view and at least one detector for detecting transmission light reflected by the object. A photonic network has a plurality of irradiation points to each of which transmission light, in particular in each case of exactly one light source, can be supplied. The transmission light exits into the transmission optics and ultimately exits into the field of view. A plurality of irradiation points that are arranged directly next to one another or that are directly adjacent are in this respect configured to irradiate transmission light into partial fields of view, in particular different partial fields of view and/or a plurality of partial fields of view arranged next to one another or are adjacent.

Abstract: To provide a distance and velocity measurement apparatus that can be adopted preferably in a LiDAR or a sensor for a robot, wherein the apparatus can prevent deterioration of SN ratio even in a case where an object in an external environment vibrates. A LiDAR 20 according to the present embodiment includes a first laser apparatus 1a, a second laser apparatus 1b, a polarization-maintaining type optical fiber 2, a WDM filter 6, an optical fiber coupler 3a, an optical amplifier 11, an input/output unit 4, an optical scanner 5, a second optical fiber coupler 3b, a balanced photodetector 7, and a square-law detector 9. Further, a delay line 10 composed of a polarization-maintaining optical fiber is provided on the local port 2b.

Abstract: Systems and methods for optical amplifier failure prediction using Machine Learning (ML), such as for an Erbium-Doped Fiber Amplifier (EDFA), are described. A method include obtaining a plurality of inputs from an optical amplifier associated with an optical network; analyzing the plurality of inputs with a trained machine learning model; obtaining an estimate of a total pump current of the optical amplifier as an output of the trained machine learning model; and comparing the estimate of a total pump current to a measured total pump current of the optical amplifier. The steps can include determining a health of the optical amplifier based on the comparing.

Abstract: Techniques for improving gain equalization in C- and L-band (“C+L”) erbium-doped fiber amplifier (EDFAs) are provided. For example, the C- and L-band amplification sections of a C+L EDFA may be separated and configured in a parallel arrangement or a serial arrangement. For both the parallel and serial arrangements, the C- and L-band amplification sections may share a common gain flattening filter (GFF) or each amplification section may include and employ a separate GFF. Moreover, in some examples, an “interstage” L-band GFF may be located before or upstream of the L-band amplification section such that the L-band optical signal is gain-equalized or flattened prior to the L-band amplification section amplifying the L-band.

Abstract: An apparatus includes a first photonic crystal fiber. The first photonic crystal fiber includes a first dispersion at a pump wavelength. The first photonic crystal fiber includes a zero dispersion. The pump wavelength is within 100 nm of the zero dispersion. The first dispersion is normal. The first photonic crystal fiber includes a first mode field diameter at the pump wavelength. The apparatus also includes a second photonic crystal fiber coupled to the first photonic crystal fiber and outputs a broadband spectrum. The second photonic crystal fiber includes a second dispersion at the pump wavelength. The second dispersion is anomalous. The second dispersion is negative, and the first dispersion is positive. The second photonic crystal fiber includes a second mode field diameter at the pump wavelength. The second mode field diameter is smaller than the first mode field diameter.

Abstract: A carrier medium is designed as a waveguide on which a coupling region and a decoupling region are provided. The coupling region is designed to couple light, which has been emitted from a light source and reflected on an object in the surroundings, into the carrier medium. The coupled reflected light is then transmitted to the decoupling region by internal reflection, and the reflected light is decoupled again at the decoupling region and is transmitted to the at least one sensor device, which is designed as a time-of-flight camera device. The sensor device provides the detected light in the form of sensor data, describing the propagation time of the light reflected on the object, to an analysis device that obtains object data, which describes the position of the object.

Abstract: An optical reception device includes: an optical demultiplexer that has an input port and output ports, and configured to demultiplex a wavelength-multiplexed signal light input from the input port into a signal light for each wavelength and output the signal light from each of the output ports; a multi-wavelength light output circuit configured to output a wavelength light for each wavelength included in the wavelength-multiplexed signal light to the input port of the optical demultiplexer; and a processor configured to control the optical demultiplexer and the multi-wavelength light output circuit, wherein the optical demultiplexer includes symmetric Mach-Zehnder interferometers that each have a pair of arms of different lengths, and adjustors respectively that adjust optical phases in the asymmetric Mach-Zehnder interferometers, the asymmetric Mach-Zehnder interferometers are connected to each other in a tree-like shape so as to connect the input port and the output ports.

Abstract: A method including emitting, by a light emitter, a first light pulse at a first time; activating a first light detector and a second light detector with different fields of view, emitting, by the light emitter, a second light pulse at a second time; receiving return light by the first light detector or the second light detector at a third time; and determining, based on the return light being detected by the first light detector or the second light detector, whether the return light is based on the first light pulse or the second light pulse when the first light pulse and second light pulse are simultaneously traversing an environment for a period of time.

Abstract: Disclosed are a control method and an optical fiber amplifier. The optical fiber amplifier is configured to execute the control method. The method comprises: initially adjusting a target gain on the basis of a first offset gain to obtain the post-initial-adjustment target gain; when the actual power of the pump laser reaches target power determined on the basis of the post-initial-adjustment target gain, obtaining, on the basis of a first signal optical power and a second signal optical power, a second offset gain and a first offset slope through calculation; adjusting again the post-initial-adjustment target gain according to the second offset gain to obtain a adjusted target gain; and adjusting a target slope according to the first offset slope to obtain a adjusted target slope. This solution can provide high precision control for the gain and the slope of the optical fiber amplifier.

Abstract: An optical sensor comprises a light-emitting element configured to emit light in a region where an object is present; a light-receiving element configured to receive reflected light from the object; a generation unit configured to generate a histogram indicating a relationship between a time from emission of the light by the light-emitting element to reception of the reflected light by the light-receiving element and an intensity of the reflected light received by the light-receiving element; a first calculation unit configured to calculate skewness of the histogram; and a second calculation unit configured to calculate a distance between the optical sensor and the object with reference to the histogram and the skewness.

Abstract: Apparatus for providing optical radiation (9), which apparatus comprises; a first seed source (1) for providing first seeding radiation (11); a second seed source (2) for providing second seeding radiation (12); a coupler (3) connected to the first seed source (1) and the second seed source (2) for coupling the first seeding radiation (11) and the second seeding radiation (12) together; and at least one amplifier (4) for amplifying the first seeding radiation (11) and the second seeding radiation (12).

Abstract: An EDFA may include an input photodiode configured to generate a control signal based on an input signal. The EDFA may include a blind stage configured to generate an amplified signal based on the control signal and the input signal. The EDFA may include a non-blind stage configured to generate an output signal based on the amplified signal within the blind stage, the control signal, and a feedback signal. The EDFA may include a filter configured to generate a filtered signal based on the output signal. The EDFA may include an output photodiode configured to generate the feedback signal based on the filtered signal. The EDFA may include an alarm device. A signal within the non-blind stage may be generated based on the feedback signal and the control signal. The alarm device may be configured to generate an alarm signal when the signal exceeds a threshold value.