Methods and systems for surface structuring to increase emissivity of one or more samples comprising: generating electromagnetic radiation from a femtosecond fiber laser, wherein the electromagnetic radiation comprises a wavelength, a pulse repetition rate, a pulse width, a pulse energy, and an average power; coupling the electromagnetic radiation from the femtosecond fiber laser to an autofocusing scanner, wherein the autofocusing scanner is configured to scan and focus the electromagnetic radiation onto the one or more samples; and using a computer to adjust the pulse repetition rate and the pulse energy of the femtosecond fiber laser and to control the autofocusing scanner to scan and focus the electromagnetic radiation onto the one or more samples to fabricate micro spikes onto the surface of the one or more samples in order to increase the emissivity of the one or more samples. Other embodiments are described and claimed.

The inventive Device is comprising a laser rangefinder for determining the distance along a laser axis between the device and a target object. The laser rangefinder is comprising a pumping laser and a thulium and/or holmium doped fiber laser with a thulium and/or holmium doped fiber section and two Bragg gratings arranged on both sides of the thulium and/or holmium doped fiber section of the thulium and/or holmium doped fiber laser wherein the thulium and/or holmium doped fiber laser is pumped by the pumping laser and configured to emit laser light with a wavelength in the range of 1900 nm to 2150 nm. The inventive device has an improved applicability.

A broadband optical amplifier for operation in the 2 μm visible wavelength band is based upon a single-clad Tm-doped fiber amplifier (TDFA). A compact pump source uses a combination of low-power laser diode with a fiber laser to provide a multi-watt pump beam without needing to include thermal management and/or pump wavelength stability components. The broadband optical amplifier is therefore able to be relatively compact device with fiber coupled output powers of >0.5 W CW, high small signal gain, low noise figure, and large OSNR, important for use as a versatile wideband preamplifier or power booster amplifier.

A Raman fiber laser source is configured with a feeding fiber delivering MM pump radiation to an inner cladding of double-clad MM Raman fiber laser. The MM pump beam radiation has a sufficient power to produce Raman scattering in the MM Raman fiber converting the pump radiation to a MM signal radiation at a Raman-shifted wavelength λram which is longer than a wavelength λpump of the pump radiation. The Raman laser source further has a pair of spaced reflectors defining therebetween a resonator for the signal radiation at a 1.sup.st Stokes wavelength and flanking at least part of the MM core of the Raman fiber which is provided with a central core region which is doped with impurities for enhancing Raman process. The reflectors and central core region are dimensioned to correspond to the fundamental mode of the MM signal radiation which is output from the Raman fiber with an M.sup.2 factor ≤1.1 and in a power range between a few kW and tens of kW.

A lidar system comprising with a light source, an optical link, and a sensor head. The light source can include a seed laser to produce pulses of light and an optical preamplifier to amplify the pulses of light. The optical link can convey amplified pulses of light to the sensor head remotely located from the light source. The sensor head can include an optical booster amplifier, a scanner to scan amplified output pulses of light across a field of regard, and a receiver to detect pulses of light scattered by a target located a distance from the sensor head.

An on-chip ultra-narrow linewidth laser and a method for obtaining a single-longitudinal mode ultra-narrow linewidth optical signal are provided in the present invention. The on-chip ultra-narrow linewidth laser includes a laser generating gain unit for generating a broad-spectrum initial optical signal and performing wavelength filtering on the generated optical signal, and also includes a distributed scattering feedback unit for performing linewidth compression on the optical signal; the laser generating gain unit is connected with the distributed scattering feedback unit, so that the optical signal generated by the laser generating gain unit is subjected to wavelength filtering and then output to the light guide component of the distributed scattering feedback unit to scatter to form an optical signal with a narrower linewidth to achieve linewidth compression, and the optical signal returning along the original path and fed back to the optical signal of the laser generating gain unit is subjected to gain amplification and wavelength filtering once again, repeating until achieving a steady state so as to obtain a single-longitudinal mode ultra-narrow linewidth optical signal. The laser can obtain a steady single-longitudinal mode ultra-narrow linewidth optical signal, and is simple in structure and small in volume.

A modular and scalable high-power fiber laser system is configurable to generate 1 kW or more of laser output, and includes one or more separable pump modules separately disposed from each other, each pump module including a plurality of fiber-coupled component pump sources optically combined by one or more fiber-based pump module pump combiners, each pump module providing one or more pump module fiber outputs, and a gain module separately disposed from the one or more separable pump modules and including one or more gain module pump fiber inputs optically coupled to corresponding ones of the pump module fiber outputs, and including a gain fiber optically coupled to the one or more gain module pump fiber inputs, the gain fiber configured to generate a gain module fiber output power scalable in relation to the number and power of said pump module fiber outputs coupled to the gain fiber.

Disclosed is a system and method for remote sensing, surface profiling, object identification, and aiming based on two-photon population inversion and subsequent photon backscattering enhanced by superradiance using two co-propagating pump waves. The present disclosure enables efficient and highly-directional photon backscattering by generating the pump waves in properly pulsed time-frequency modes, proper spatial modes, with proper group-velocity difference in air. The pump waves are relatively delayed in a tunable pulse delay device and launched to free space along a desirable direction using a laser-pointing device. When the pump waves overlap in air, signal photons will be created through two-photon driven superradiant backscattering if target gas molecules are present. The backscattered signal photons propagate back, picked using optical filters, and detected. By scanning the relative delay and the launching direction while the signal photons are detected, three-dimensional information of target objects is acquired remotely.

A fiber laser is configured with a double clad fiber with a core doped with ions of Erbium (Er.sup.+3) and Ytterbium (Yb.sup.+3). At least two spaced apart high and low reflection mirrors flank the core and define a resonant cavity therebetween. The fiber laser further includes a pump laser outputting light in a 1.02-1.06 μm wavelength range which is coupled into the Yb:Er doped double clad fiber.

A fiber amplifier includes a double clad fiber with a core doped with ions of Erbium (Er.sup.+3) and Ytterbium (Yb.sup.+3), and a pump laser generating radiation at a pump wavelength in a 1.02-1.06 wavelength range, a pump laser outputting light in a 1.02-1.06 μm wavelength range coupled into the Yb:Er doped double clad fiber.

The disclosed fiber laser and fiber amplifier each have a significantly higher lasing threshold in the 1 μm wavelength range than the threshold of the known schematics operating at a 9xx nm pump wavelength.

In an example, an apparatus to tandem pump a fiber laser or fiber amplifier may include a combiner; a power amplifier or a power oscillator, or a combination thereof, coupled to an output of the combiner; a seed laser to output light to the power amplifier or the power oscillator, or the combination thereof, via the combiner; and a tandem pump to generate light of a pump source signal, wherein the light of the pump source signal is output to the combiner to cladding pump the power amplifier or the power oscillator, or the combination thereof. Other embodiments may be disclosed and/or claimed.