A laser system having a multi-pass amplifier system which includes at least one seed source configured to output at least one seed signal having a seed signal wavelength, at least one pump source configured to output at least one pump signal, at least one multi-pass amplifier system in communication with the seed source and having at least one gain media, a first mirror, and at least a second mirror therein, the gain media device positioned between the first mirror and second mirror and configured to output at least one amplifier output signal having an output wavelength range, the first mirror and second mirror may be configured to reflect the amplifier output signal within the output wavelength range, and at least one optical system may be in communication with the amplifier system and configured to receive the amplifier output signal and output an output signal within the output wavelength range.

A mode-lockable ring oscillator includes a gain element for amplifying an optical pulse into an amplified pulse, a nonlinear optical element for broadening the amplified pulse into a first spectrally-broadened pulse, a first optical filter for filtering the first spectrally-broadened pulse into a first filtered pulse, a passive nonlinear optical element for broadening the first filtered pulse into a second spectrally-broadened pulse, and a second optical filter for filtering the second spectrally-broadened pulse into a second filtered pulse. The first and second optical filters have passbands that partially overlap such that the ring cavity can lase CW. With these spectrally overlapping passbands, the mode-lockable ring oscillator can directly initiate single-pulse mode-locking by modulating pump power that pumps the gain element. After this modulation has stopped, the mode-lockable ring oscillator maintains this single-pulse mode-locking while the passbands remain spectrally overlapped.

In some implementations, a device may apply a modulation to an electrical current to derive a modulated electrical current. The device may supply the modulated electrical current to an optical pump source for an optical amplifier to cause the optical pump source to emit light based on the modulated electrical current. The device may generate a signal based on an optical power of the light emitted by the optical pump source. The device may filter the signal with respect to a feedback signal that is to result from the modulated electrical current to derive a filtered signal. The device may process the filtered signal to identify whether the feedback signal is present in the filtered signal based on a power indicated by the filtered signal. Whether the feedback signal is present indicates a state of the optical pump source.

A method for providing spectral beam combining (SBC) including generating a plurality seed beams each having a central wavelength and a low fill factor profile, where the wavelength of all of the seed beams is different; amplifying the seed beams; causing the amplified beams to expand as they propagate so as to be converted from the low fill factor profile to a high fill factor profile where the high fill factor profile tapers to a lower value at a perimeter of each beam; causing a wavefront of the converted beams to flatten to provide a plurality of adjacent SBC beams having different wavelengths with minimal overlap and a minimal gap between the beams; collimating the SBC beams; and directing the collimated SBC beams onto an SBC element that spatially diffracts the individual beam wavelengths and directing the beams in the same direction as a combined output beam.

A Raman fiber laser includes a pump light source, a reflective end mirror, a wavelength division multiplexer, a Raman gain fiber, and an output end mirror. The output end mirror is an ultra-low reflectance fiber Bragg grating. The reflective end mirror is connected to a reflective end of the wavelength division multiplexer. The pump light source is connected to an input end of the wavelength division multiplexer. One end of the Raman gain fiber is connected to a common end of the wavelength division multiplexer, and the other end of the Raman gain fiber is connected to the ultra-low reflectance fiber Bragg grating. The laser of the present invention can reduce loss of laser light at the reflective end mirror, thereby increasing laser light optical conversion efficiency and output power, and simultaneously achieving high time domain stability and extremely low coherence.

A semiconductor laser device includes: a support base having a plurality of mounting surfaces arranged in a first direction, wherein heights of the mounting surfaces from a reference plane that is parallel to the first direction decrease stepwise or gradually along the first direction; a first semiconductor laser element secured to a first mounting surface; a second semiconductor laser element secured to a second mounting surface; a first slow-axis collimator lens secured to the first mounting surface, the first slow-axis collimator lens being located at a position at which the first laser light is incident; a second slow-axis collimator lens directly or indirectly secured to the second mounting surface, the second slow-axis collimator lens being located at a position at which the second laser light is incident; and a first sealing cover that defines an inner space in which the first and second semiconductor laser elements are held.

A laser system is provided. The laser system comprises: a seed laser configured to produce a sequence of seed light pulses, wherein the sequence of seed light pulses are produced with variable time intervals in a sweep cycle; a pump laser configured to produce pump light having variable amplitude in the sweep cycle; and a control unit configured to generate a command to the pump laser to synchronize the pump light with the sequence of seed light pulses.

An optical fiber amplifier compatible with a small form-factor pluggables (SFP+) package includes a housing, and a circuit device and an optical path device that are disposed in the housing, where the housing includes a structure compatible with an SFP+ package and is provided with an accommodation space; both the circuit device and the optical path device are located in the accommodation space, and the optical path device is located below the circuit device; the circuit device is provided with a card edge connector, and the card edge connector can be exposed outside the housing. The optical fiber amplifier compatible with an SFP+ package has a compact internal space. The amplifer has an appearance compatible with a standard SFP+ package. An electrical interface pin also meets a requirement of an existing SFP+ package, and dynamic plugging and plug-and-play can be satisfied.

An ultraviolet laser apparatus includes: a semiconductor laser that emits an excitation laser light; a fiber laser medium to which the excitation laser light enters from the semiconductor laser and that causes laser oscillation; and an external resonator that: converts a wavelength of a laser light oscillated in the fiber laser medium, and outputs an ultraviolet region continuous wave of at least 0.1W.

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.