Provided is a carbon isotope analysis device including a carbon dioxide isotope generator provided with a combustion unit that generates gas containing carbon dioxide isotope from carbon isotope, and a carbon dioxide isotope purifying unit; a spectrometer including optical resonators having a pair of mirrors, and a photodetector that determines intensity of light transmitted from the optical resonators; and a light generator including a single light source, a first optical fiber that transmits first light from the light source, a second optical fiber that generates second light of a longer wavelength than the first light, the second optical fiber splitting from the first optical fiber and coupling therewith downstream, a first amplifier on the first optical fiber, a second amplifier on the second optical fiber, different in band from the first amplifier, and a nonlinear optical crystal.

A method for preventing feedback light of a laser, includes fusion-splicing a target fiber to an output fiber of a laser, so that laser lights generated by the laser are output from the target fiber. A refractive index of a core of the output fiber of the laser is less than a refractive index of a core of the target fiber. When a feedback light of a laser light of the laser is reversely transmitted to a fusion-splicing surface through the target fiber, total reflection occurs due to a refractive index difference on the fusion-splicing surface, so that the feedback light is transmitted along the transmission direction of the laser light, and is prevented from entering the output fiber along the reverse direction of the laser light and further entering the laser's resonant cavity to damage the laser component or burn out the gain fiber.

Mid-infrared-transparent optical fiber products with enhanced resistance to OH diffusion are disclosed, which may be used fiber laser oscillator and amplifiers systems. In one embodiment, an optical fiber product may include optical fiber configured for propagation of mid-infrared radiation toward a light-radiating endface of or coupled to the optical fiber, and a diffusion barrier disposed on the light-radiating endface and configured for allowing the mid-infrared radiation emanating from the light-radiating endface to pass therethrough and for preventing OH diffusion therethrough toward the light-radiating endface. In another embodiment, an optical fiber product may include an optical fiber for propagation of mid-infrared radiation and an endcap coupled to the optical fiber for receiving therefrom the mid-infrared radiation and radiating out the mid-infrared radiation, the endcap being made of an endcap material that has no or a low amount of fluoride and that is less permeable to OH diffusion than the fiber-optic material.

A laser system based on nonlinear pulse compression and a LMA optical fiber therefor are provided. The LMA optical fiber is configured to amplify seed light pulses and promote the onset of nonlinear spectral broadening. The LMA optical fiber includes a first section having constant core and cladding diameters and receiving and supporting propagation of the light pulses in multiple transversal modes. The first section is configured to suppress high order modes propagating therealong. The LMA optical fiber further includes a tapered second section receiving the fundamental mode from the first section, the core and cladding diameters increasing gradually along said second section so as to provide an adiabatic transition of the fundamental mode. The LMA optical fiber further includes an optional third section having constant core and cladding diameters. Dispersive compression of the light pulses outputted by the LMA optical fiber provides excellent beam quality and high peak powers.

A fiber includes a core and cladding, both of which may have temperature dependent indices of refraction. The materials and size of the core and cladding may be selected such that as the temperature of the core and/or cladding is heated above room temperature, the fiber transitions from supporting multimode optical waveguiding to supporting single mode waveguiding.

Systems and methods include a radiation source configured to generate a first waveform, a first separator configured to separate the first waveform into linearly polarized second and third waveforms, a first modulator configured to modulate at least one of a phase and a polarization of the second waveform to generate a fourth waveform, a second modulator configured to modulate at least one of a phase and a polarization of the third waveform to generate a fifth waveform, a first combiner configured to combine the fourth and fifth waveforms to generate a sixth waveform, an amplifier configured to amplify the sixth waveform to generate a seventh waveform, a second separator configured to separate the seventh waveform into a plurality of amplified waveforms, and beam directing optics configured to direct the plurality of amplified waveforms to form an output waveform at a target location.

An optical fiber includes a core that propagates a light that includes a wavelength of 1060 nm. The light propagates in the core at least in an LP01 mode and an LP11 mode. A difference between a propagation constant of the light in the LP01 mode and a propagation constant of the light in the LP11 mode is 2000 rad/m or smaller. The expression

[00001]$L\frac{.Math.M^2}{-2.Math.3.Math.7.Math.21.Math.0^{-6}.Math.+4.8.Math.1.Math.91.Math.0^{-3}}$

is satisfied, where L is a length, M.sup.2 is a beam quality of light, M.sup.2 is a deterioration amount of the beam quality of light due to propagation in the optical fiber.

A method for generating a single-cavity dualcomb or multicomb for laser spectroscopy, the method comprising the steps of providing a laser system comprising a pump source, a gain medium, and a resonator having a spectral filter; spectrally filtering, by the spectral filter, light in the resonator and attenuating, in particular blocking, by the spectral filter, one or more wavelength bands at least one of which being located completely within the gain bandwidth of the laser system such that two or more at least partially separated spectral regions are provided; mode-locking the two or more at least partially separated spectral regions.

A medical laser apparatus, including: an energy guide; a first energy source configured to generate energy for treating a target tissue through the energy guide; a second energy source configured to emit first and second aiming beams to a target tissue through the energy guide, the second aiming beam having at least one characteristic different from the first aiming beam; and a controller comprising hardware, the controller being configured to: receive a signal indicating an illumination mode from at least two illumination modes used by an endoscope to illuminate the target tissue; and control the second energy source to output the first or second aiming beam based on the indicated illumination mode.

A controller: performing one or more iterations of a first process, the first process including: selecting at least one variable operating parameter of a laser light source of a lithotripsy device; determining a value of each of a plurality of base settings of the at least one variable operating parameter selected; and performing, in order, for the each of the plurality of base settings: setting the at least one variable operating parameter selected to the value of the each of the plurality of base settings; and controlling the laser light source to output laser light based on the value of the each of the plurality of base settings set; selecting one of the plurality of base settings; and performing one or more iterations of a second process, the second process including controlling the laser light source based on the one of the plurality of base settings selected.