A system for producing single-frequency or near-single-frequency operation of a laser beam includes a laser for emitting a laser beam at each one of a plurality of cavity lengths, A detector is configured to receive at least a portion of the laser beam emitted, and generate a signal. A computer system is configured to identify at least one beat note in the signal for each of at least one of the plurality of cavity lengths, the at least one beat note indicating the presence of one or more higher-order transverse modes, longitudinal modes, or both, in the received at least the portion of the laser beam emitted at the at least one of the plurality of cavity lengths. The cavity is adjusted to one of the plurality of cavity lengths for eliminating or minimizing the at least one beat note.

An optical element moving apparatus includes a first holder configured to hold a first optical element, a second holder configured to hold a second optical element and having an inclination that inclines with respect to a first direction in which the second holder approaches the first holder, a guide section configured to be capable of moving the second holder in a direction parallel to the first direction, and an elastic member disposed in a position which is located between the first holder and the second holder and through which a first plane passes, the first plane intersecting the inclination at right angles and being parallel to the first direction.

A wavelength control method of a laser apparatus includes sequentially obtaining target wavelength data of a pulse laser beam, sequentially saving the target wavelength data, sequentially measuring a wavelength of the pulse laser beam to obtain a measured wavelength, calculating a wavelength deviation using the measured wavelength and the target wavelength data at a time before a time when the measured wavelength is obtained, and feedback-controlling the wavelength of the pulse laser beam using the wavelength deviation.

A system for producing single-frequency or near-single-frequency operation of a laser beam includes a laser for emitting a laser beam at each one of a plurality of cavity lengths, A detector is configured to receive at least a portion of the laser beam emitted, and generate a signal. A computer system is configured to identify at least one beat note in the signal for each of at least one of the plurality of cavity lengths, the at least one beat note indicating the presence of one or more higher-order transverse modes, longitudinal modes, or both, in the received at least the portion of the laser beam emitted at the at least one of the plurality of cavity lengths. The cavity is adjusted to one of the plurality of cavity lengths for eliminating or minimizing the at least one beat note.

An apparatus includes an auto-alignment laser configured to generate an auto-alignment laser beam. The apparatus also includes a spectral beam combiner having a diffraction grating. The diffraction grating is configured to diffract multiple input laser beams to produce a combined beam having a higher power or energy compared to the individual input laser beams. The diffraction grating is also configured to diffract the auto-alignment laser beam so that a portion of the auto-alignment laser beam co-propagates in a common direction with the combined beam. Wavelengths of the input laser beams and the auto-alignment laser beam may be selected such that portions of the input laser beams and the portion of the auto-alignment laser beam diffract from the diffraction grating in the common direction. The portion of the auto-alignment laser beam that co-propagates with the combined beam may include a higher-order diffraction of the auto-alignment laser beam from the diffraction grating.

An apparatus includes an auto-alignment laser configured to generate an auto-alignment laser beam. The apparatus also includes a spectral beam combiner having a diffraction grating. The diffraction grating is configured to diffract multiple input laser beams to produce a combined beam having a higher power or energy compared to the individual input laser beams. The diffraction grating is also configured to diffract the auto-alignment laser beam so that a portion of the auto-alignment laser beam co-propagates in a common direction with the combined beam. Wavelengths of the input laser beams and the auto-alignment laser beam may be selected such that portions of the input laser beams and the portion of the auto-alignment laser beam diffract from the diffraction grating in the common direction. The portion of the auto-alignment laser beam that co-propagates with the combined beam may include a higher-order diffraction of the auto-alignment laser beam from the diffraction grating.

A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ΔL bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ΔL bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ΔL bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

A waveguide gas laser having a laser resonator cavity of a variable length is subjected to cyclical varying of the length of the cavity during generation of a laser beam a length variation amount sufficient to force a laser beam generated in the resonator cavity though a substantially complete optical longitudinal cavity mode at a rate operable to smooth at least one laser beam parameter variation. In this manner variation in the laser beam parameter is averaged by moving through at least a portion of an optical longitudinal cavity mode.