Abstract: A lidar system with a pulsed laser diode configured to produce an optical seed pulse of light at an operating wavelength between approximately 1400 nm and approximately 1600 nm. The lidar system may also include an optical amplifier configured to amplify the optical seed pulse to produce an eye-safe output optical pulse that is emitted into a field of view. The optical amplifier may produce an amount of amplified spontaneous emission (ASE) associated with the output optical pulse. The lidar system may include an optical filter configured to filter the output optical pulse to reduce the associated ASE. The lidar system may also include a receiver configured to detect at least a portion of the output optical pulse reflected or scattered from the field of view.

Abstract: A lidar system with a light source to emit a pulse of light into a field of view and a receiver to detect a return pulse of light which is reflected or scattered by a target in the field of view. The receiver may include an avalanche photodiode to generate an electrical-current pulse corresponding to the return pulse and a transimpedance amplifier to produce a voltage pulse that corresponds to the electrical-current pulse. A voltage amplifier may amplify the voltage pulse and a comparator may produce an edge signal when the amplified voltage pulse exceeds a threshold. A time-to-digital converter may determine a time interval based on an emission time of the pulse of light and based on the edge signal. A processor may determine a distance to the target using the time interval.

Abstract: A lidar system with a light source to emit a pulse of light into a field of view and a receiver to detect a return pulse of light which is reflected or scattered by a target in the field of view. The receiver may include an avalanche photodiode to generate an electrical-current pulse corresponding to the return pulse and a transimpedance amplifier to produce a voltage pulse that corresponds to the electrical-current pulse. A voltage amplifier may amplify the voltage pulse and a comparator may produce an edge signal when the amplified voltage pulse exceeds a threshold. A time-to-digital converter may determine a time interval based on an emission time of the pulse of light and based on the edge signal. A processor may determine a distance to the target using the time interval.

Abstract: Hybrid laser systems include fiber amplifiers using tapered waveguides and solid-state amplifiers. Typically, such systems represent a technically simple and low cost approach to high peak power pulsed laser systems. The tapered waveguides generally are provided with an active dopant such as a rare earth element that is pumped with one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section. A seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode. The waveguide taper permits amplification to higher peak power values than comparable small mode area fibers. The fiber amplified beam is then directed to a solid state amplifier, such as a thin disk or rod-type laser amplifier.

Abstract: An apparatus for producing coherent, pulsed ultraviolet light with pulse durations that range between 1 ps and 1 ?s includes one or more source lasers in the visible or near-infrared frequency range. The apparatus also includes one or more FC stages, at least one of the one or more FC stages including a nonlinear FC device and one or more optical elements. The optical elements include a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component. The FC device includes a huntite-type aluminum double borate nonlinear optical material configured to produce FC light having a wavelength between 190 and 350 nm and a composition given by RAl3B4O12, where R comprises one or a plurality of elements {Sc, La, Y, Lu}. The nonlinear optical material is characterized by an optical transmission greater than 70% over the wavelength range of 190 to 350 nm.

Abstract: An apparatus for producing coherent pulsed light with a fiber-based master oscillator/fiber amplifier architecture includes a fiber-coupled mode-locked laser source. The fiber-coupled mode-locked laser source is configured to provide pulses having a pulse duration of less than 1 ns. The apparatus also includes a fiber-coupled amplitude modulator optically coupled to the fiber-coupled mode-locked laser source. The fiber-coupled amplitude modulator is capable of gate durations greater than 1 ns. The apparatus further includes a saturated fiber power amplifier optically coupled to the fiber-coupled amplitude modulator.

Abstract: Hybrid laser systems include fiber amplifiers using tapered waveguides and solid-state amplifiers. Typically, such systems represent a technically simple and low cost approach to high peak power pulsed laser systems. The tapered waveguides generally are provided with an active dopant such as a rare earth element that is pumped with one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section. A seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode. The waveguide taper permits amplification to higher peak power values than comparable small mode area fibers. The fiber amplified beam is then directed to a solid state amplifier, such as a thin disk or rod-type laser amplifier.

Abstract: An apparatus for producing coherent, pulsed ultraviolet light with pulse durations that range between 1 ps and 1 ?s includes one or more source lasers in the visible or near-infrared frequency range. The apparatus also includes one or more FC stages, at least one of the one or more FC stages including a nonlinear FC device and one or more optical elements. The optical elements include a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component. The FC device includes a huntite-type aluminum double borate nonlinear optical material configured to produce FC light having a wavelength between 190 and 350 nm and a composition given by RAl3B4O12, where R comprises one or a plurality of elements {Sc, La, Y, Lu}. The nonlinear optical material is characterized by an optical transmission greater than 70% over the wavelength range of 190 to 350 nm.

Abstract: An apparatus for producing coherent, pulsed ultraviolet light with pulse durations that range between 1 ps and 1 ?s includes one or more source lasers in the visible or near-infrared frequency range. The apparatus also includes one or more FC stages, at least one of the one or more FC stages including a nonlinear FC device and one or more optical elements. The optical elements include a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component. The FC device includes a huntite-type aluminum double borate nonlinear optical material configured to produce FC light having a wavelength between 190 and 350 nm and a composition given by RAl3B4O12, where R comprises one or a plurality of elements {Sc, La, Y, Lu}. The nonlinear optical material is characterized by an optical transmission greater than 70% over the wavelength range of 190 to 350 nm.

Abstract: An apparatus for producing coherent, continuous wave, ultraviolet light, includes one or more source lasers in the visible or near-infrared frequency range. The apparatus also includes one or more frequency conversion stages. Each of the one or more frequency conversion stages includes one or more reflectors, an optical resonator, one or more waveguide components, or one or more fiber optic components. At least one of the one or more frequency conversion stages includes a huntite-type aluminum double borate nonlinear optical material to produce light having a wavelength between 190 and 350 nm. The huntite-type aluminum double borate material has a composition given by MAl3B4O12, where M is one or a plural combination of elements {Sc, La, Y, or Lu}.

Abstract: A fiber laser with reduced stimulated Brillouin scattering includes a spool having a height and characterized by an induced temperature gradient with the height. The fiber laser also includes a fiber wrapped on the spool and characterized by a signal power increasing along the length of the fiber. The induced temperature gradient is a function of the signal power along the fiber.

Abstract: A fiber laser system includes a master oscillator configured to generate linear polarized infrared laser radiation with wavelengths of 1015-1085 nm, pulses with durations of 100 ps to 10 ns, pulse train repetition rates of 1 kHz to 10 MHz, spectral bandwidth less than 0.5 nm, and a predominately single spatial mode and a polarization-maintaining optical isolator optically coupled to the master oscillator. The fiber laser system also includes a fiber amplifier system optically coupled to the optical isolator and including a power amplifier configured to amplify the laser radiation transmitted through the optical isolator. The power amplifier includes a polarization-maintaining, large-mode-area, multiple-clad Yb-doped gain fiber having a core, an inner cladding, and at least an outer cladding, one or more diode pump lasers emitting pump light of a nominal wavelength of 976 nm, and a pump coupler configured to couple the pump light into the gain fiber.

Abstract: A fiber laser system includes a predominately single spatial mode, linearly polarized master oscillator providing a set of optical pulses and a polarization-maintaining optical isolator optically coupled to the master oscillator. The fiber laser system also includes a fiber amplifier optically coupled to the optical isolator and including a power amplifier comprising a double clad gain fiber, one or more pump lasers, and a pump coupler. The fiber laser system further includes a pulse compression stage optically coupled to the fiber amplifier. The pulse compression stage includes a volume holographic phase grating. Moreover, the fiber laser system includes a nonlinear frequency conversion stage optically coupled to the pulse compression stage.

Abstract: An apparatus for producing coherent, pulsed ultraviolet light with pulse durations that range between 1 ps and 1 ?s includes one or more source lasers in the visible or near-infrared frequency range. The apparatus also includes one or more FC stages, at least one of the one or more FC stages including a nonlinear FC device and one or more optical elements. The optical elements include a reflector, a focusing element, a polarization-controlling optic, a wavelength separator, or a fiber optic component. The FC device includes a huntite-type aluminum double borate nonlinear optical material configured to produce FC light having a wavelength between 190 and 350 nm and a composition given by RAl3B4O12, where R comprises one or a plurality of elements {Sc, La, Y, Lu}. The nonlinear optical material is characterized by an optical transmission greater than 70% over the wavelength range of 190 to 350 nm.

Abstract: An apparatus for producing coherent pulsed light with a fiber-based master oscillator/fiber amplifier architecture includes a fiber-coupled mode-locked laser source. The fiber-coupled mode-locked laser source is configured to provide pulses having a pulse duration of less than 1 ns. The apparatus also includes a fiber-coupled amplitude modulator optically coupled to the fiber-coupled mode-locked laser source. The fiber-coupled amplitude modulator is capable of gate durations greater than 1 ns. The apparatus further includes a saturated fiber power amplifier optically coupled to the fiber-coupled amplitude modulator.

Abstract: An apparatus for producing coherent, continuous wave, ultraviolet light, includes one or more source lasers in the visible or near-infrared frequency range. The apparatus also includes one or more frequency conversion stages. Each of the one or more frequency conversion stages includes one or more reflectors, an optical resonator, one or more waveguide components, or one or more fiber optic components. At least one of the one or more frequency conversion stages includes a huntite-type aluminum double borate nonlinear optical material to produce light having a wavelength between 190 and 350 nm. The huntite-type aluminum double borate material has a composition given by MAl3B4O12, where M is one or a plural combination of elements {Sc, La, Y, or Lu}.

Abstract: A fiber laser system includes a master oscillator configured to generate linear polarized infrared laser radiation with wavelengths of 1015-1085 nm, pulses with durations of 100 ps to 10 ns, pulse train repetition rates of 1 kHz to 10 MHz, spectral bandwidth less than 0.5 nm, and a predominately single spatial mode and a polarization-maintaining optical isolator optically coupled to the master oscillator. The fiber laser system also includes a fiber amplifier system optically coupled to the optical isolator and including a power amplifier configured to amplify the laser radiation transmitted through the optical isolator. The power amplifier includes a polarization-maintaining, large-mode-area, multiple-clad Yb-doped gain fiber having a core, an inner cladding, and at least an outer cladding, one or more diode pump lasers emitting pump light of a nominal wavelength of 976 nm, and a pump coupler configured to couple the pump light into the gain fiber.

Abstract: A fiber laser with reduced stimulated Brillouin scattering includes a spool having a height and characterized by an induced temperature gradient with the height. The fiber laser also includes a fiber wrapped on the spool and characterized by a signal power increasing along the length of the fiber. The induced temperature gradient is a function of the signal power along the fiber.

Abstract: A feature detection apparatus includes a reflective imaging system, a transmissive imaging system, and memory for generating an image of a workpiece. The reflective imaging system generates a first bit image of a surface of the workpiece. The transmissive imaging system generates a second, different bit image of the density of the workpiece. The two images are then combined in memory into a more complete image that contains data describing the surface and interior of the workpiece. The apparatus also includes a filter for enhancing the combined bit image so that physical features of the workpiece are accurately detected. The filter is constructed to perform the following steps. For detecting a feature of interest, the filter determines a mean, standard deviation, and normal distribution of the image's pixel intensities.

Abstract: This invention includes an optical characterization method capable of determining various characteristics of samples that preferably include naturally-occurring color deviations. In the preferred embodiment, this method is used in connection with food products and, particularly, potato products such as french fried potatoes. The method of this invention overcomes such disadvantages by generating from the RGB pixel values a sample-based color space that corresponds to the naturally-occurring color deviations of the samples. Preferably, the method includes generating HSI pixel values that correspond to the RGB pixel values and are defined with respect to an HSI color space having hue, saturation, and intensity coordinates. The sample-based representation of the color characteristics of the samples is determined on a pixel-by-pixel basis. As a result, color grades for the samples can be assigned according to the distribution of pixels within the sample-based representation.