The optical amplifier has an inhomogeneously broadened gain material capable of generating a plurality of ensemble gains. A first optical filter and a second optical filter are provided in the photonic integrated circuit. The apparatus has a first laser cavity which includes the optical amplifier, the first optical filter optically coupled to each other and at least two mirrors. The apparatus has a second laser cavity which includes the optical amplifier, the second optical filter optically coupled to each other and at least two mirrors. The first optical filter is tunable to a respective first ensemble gain generated by the optical amplifier and the second filter is tunable to a respective second ensemble gain generated by the optical amplifier; and the second ensemble gain is different from the first ensemble gain. A laser source and an optical transmitter are also disclosed.

A method of inducing light losses at a parasitic wavelength in a fiber laser system includes providing a wavelength discriminator (WD) spaced from and between feeding and process fibers or from the end output of the feeding fiber so as to induce losses of light at parasitic wavelength. The device implementing the disclosed method is configured with a laser source, the delivery fiber and WD spaced at a distance between the surface to be treated and the end of the delivery fiber, wherein the WD receives the parasitic light over free space and is configured as a dichroic filter inducing losses to the light at the parasitic wavelength.

To prevent an output decrease of laser light due to impurities formed in a Q switch. A laser machining device includes a Q-switch housing section configured by housing a Q switch and a first mirror and a wavelength converting section including a housing in which a transmission window section capable of transmitting a fundamental wave is formed, the wavelength converting section being configured by airtightly housing, with an internal space surrounded by the housing, at least a first wavelength conversion element, a second wavelength conversion element, and a second mirror. A resonator forming a resonant optical path passing through the transmission window section is configured by the first mirror in the Q-switch housing section and the second mirror in the wavelength converting section.

A laser apparatus includes: an optical fiber through which a laser beam propagates; a resin that fixes the optical fiber; a sound sensor that detects a sound produced by the resin that shrinks when a power of light propagating through the optical fiber decreases from its peak value; a storage that stores a threshold relating to a sound produced when the resin shrinks; and a comparison determination part. The comparison determination part compares a detected value representative of the sound detected by the sound sensor to the threshold stored in the storage and determines that the resin has been degraded when the detected value exceeds the threshold.

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 of inducing light losses at a parasitic wavelength in a fiber laser system includes providing a wavelength discriminator (WD) spaced from and between feeding and process fibers or from the end output of the feeding fiber so as to induce losses of light at parasitic wavelength. The device implementing the disclosed method is configured with a laser source, the delivery fiber and WD spaced at a distance between the surface to be treated and the end of the delivery fiber, wherein the WD receives the parasitic light over free space and is configured as a dichroic filter inducing losses to the light at the parasitic wavelength.

To appropriately change an output of laser light without deteriorating laser characteristics. A control section of a laser machining device controls, when a target output is larger than a predetermined threshold, an output of laser light by changing a driving current supplied to an excitation light source and, on the other hand, controls, when the target output is equal to or smaller than the threshold, the output of the laser light by changing a duty ratio of a Q switch while keeping the driving current supplied to the excitation light source substantially fixed.

Systems and methods for performing resonator fiber optic gyroscope (RFOG) resonance hopping are described herein. For example, an RFOG includes a fiber optic resonator. The RFOG also includes a plurality of laser sources that each launch a respective laser for propagation within the fiber optic resonator. Further, the RFOG includes a threshold detector that determines when the operation of at least one laser source in the plurality of laser sources exceeds a threshold associated with the operational range of an aspect of the at least one laser source. Additionally, the RFOG includes a hop control logic that adjusts the frequency of at least one laser produced by the at least one laser source one or more resonant modes of the fiber optic resonator such that the aspect of the at least one laser moves away from the threshold towards a nominal value within the operational range.

The present invention concerns a multiple soliton comb generation method comprising the steps of: providing a single optical resonator configured to support a plurality of distinct spatial modes in which light can propagate; providing an optical pump laser source; simultaneously optically pumping a plurality of distinct spatial modes of the single optical resonator to simultaneously generate independent soliton states in the distinct spatial modes and generate a plurality of frequency combs.

The invention relates to a method for maintaining the synchronism of a Fourier Domain Mode Locked (FDML) laser, the FDML laser comprising at least one dispersion-compensated resonator with at least one variably wavelength-selective optical filter, the laser light circulating in the resonator at a circulation frequency, and the wavelength selectivity of the filter being repeatedly modified at a syntonising rate, the FDML laser being synchronous when the syntonising rate is an integral multiple of the circulation frequency. Said method is characterised by the following steps: a) at least a portion of the laser light is coupled out of the resonator; b) at least a portion of the decoupled laser light is detected by means of a photodetector; c) amplitudes in the measuring signal of the photodetector are counted during successive counting intervals; and d) the circulation frequency or syntonising rate is adjusted such that the ratios of the count value to the lengths of the counting intervals are maintained within a predetermined nominal value interval.