Seeder for use with a fiber laser for generating an arbitrary shaped pulse, comprising an amplified spontaneous emission (ASE) source, a spectral filter and an arbitrary waveform generator (AWG) modulator, the ASE source for generating a continuous wave (CW) broadband pulse, the spectral filter being coupled with the ASE source for narrowing the CW broadband pulse, and the AWG modulator being coupled with the spectral filter for shaping the narrowed CW broadband pulse to an arbitrary pulse shape.

A distributed feedback laser, including: an output end including an active region including a grating including a λ/4 phase-shift region; and a non-output end including a reflecting region including a grating with uniform period. The length of the active region is smaller than or equal to 200 μm. The end facet of the output end of the laser is coated with an anti-reflection film.

An amplifier assembly may include a first heat sink plate that includes a first channel, a second heat sink plate that includes a second channel, and an amplifier rod disposed in the first channel and the second channel. The second heat sink plate may be connected with the first heat sink plate such that the first channel and the second channel align. The amplifier rod may be connected to the first heat sink plate and the second heat sink plate by a non-eutectic solder.

A laser transmitter assembly for use in a Coherent Doppler Wind Lidar (“CDWL”) system includes a telescope/scanner assembly, a receiver, and a master oscillator crystal and a power amplifier crystal each constructed of Ho:YAG. The crystals are end-pumped to transmit an output beam through the telescope/scanner assembly with a high repetition rate of 200-300 Hz and 35 mJ of energy. As part of the CDWL system, a pump laser end-pumps the master oscillator and power amplifier crystals using a pump beam having a nominal wavelength of 1.905 μm. A seed laser transmits a seeding beam into the master oscillator crystal at a nominal wavelength of 2.0965 μm. The telescope/scanner assembly transmits the generated laser beam through an atmosphere toward a scene of interest, collects a backscattered return signal, and communicates the backscattered return signal to the receiver during operation of the CDWL system.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument. The mode-locked laser can produce sub-50-ps optical pulses at a repetition rates between 200 MHz and 50 MHz, rates suitable for massively parallel data-acquisition. The optical pulses can be used to generate a reference clock signal for synchronizing data-acquisition and signal-processing electronics of the portable instrument.

Provided is a laser device capable of realizing the increased output and increased repeatability even when the surface roughness of the gain medium is large. The laser device includes: an excitation light source; a condensing optical system that condenses excitation light outputted from the excitation light source; a gain medium that receives the excitation light condensed by the condensing optical system and outputs emission light; a transparent member that has a smaller surface roughness than the gain medium and transmits the emission light outputted from the gain medium; a supersaturated absorber having a transmittance that increases as the emission light transmitted through the transparent member is absorbed; and a resonator that causes the emission light to resonate between the gain medium and the supersaturated absorber with the transparent member being interposed therebetween, wherein a dielectric multilayer film that reflects the excitation light and transmits the emission light is coated on the surface of the transparent member on the gain medium side.

Provided is a single-crystal fiber including a waveguide structure for a wavelength to be subjected to optical amplification, in which at least one end of the single-crystal fiber is planar, an angle θ between a normal to a facet of the single-crystal fiber and an optical axis of the single-crystal fiber satisfies a relationship of θ=90°−tan.sup.−1(n.sub.2/n.sub.1), where n.sub.1 represents a refractive index of a medium of a space that uses the single-crystal fiber, and n.sub.2 represents a refractive index of the single-crystal fiber for a guided light beam having a polarization direction parallel with a plane that includes the normal to the facet and the optical axis, and a diameter Dx in an X-direction and a diameter Dy in a Y-direction of a cross-section of the single-crystal fiber perpendicular to the optical axis satisfies a relationship of (n.sub.2/n.sub.1)0.9≤Dx/Dy≤(n.sub.2/n.sub.1)1.1.

An amplifier assembly may include a first heat sink plate that includes a first channel, a second heat sink plate that includes a second channel, and an amplifier rod disposed in the first channel and the second channel. The second heat sink plate may be connected with the first heat sink plate such that the first channel and the second channel align. The amplifier rod may be connected to the first heat sink plate and the second heat sink plate by a non-eutectic solder.

A planar waveguide amplifier includes a planar waveguide including a flat plate-like core; a first cladding provided on a first principal face of the core; and a second cladding provided on a second principal face of the core, and signal light and pumping light travel into the planar waveguide so that the signal light and the pumping light propagate inside the core in such a manner that optical paths of the signal light and the pumping light overlap each other, and in a zig-zag manner, and the core is an amplification medium containing a rare-earth element serving as an active ion of a three-level system, and absorbs the signal light on the basis of a reduction in intensity of the pumping light.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument. The mode-locked laser can produce sub-50-ps optical pulses at a repetition rates between 200 MHz and 50 MHz, rates suitable for massively parallel data-acquisition. The optical pulses can be used to generate a reference clock signal for synchronizing data-acquisition and signal-processing electronics of the portable instrument.