A positive high-voltage laser having a super-long discharge tube, including a gas storage tube having two ends respectively provided with a reflecting mirror and a light emitting surface; a water cooling tube in the gas storage tube; and a discharge tube inside the water cooling tube having two ends, each provided with an electrode. A liquid circulation space is between the discharge tube and the water cooling tube, and the water cooling tube extends outside the gas storage tube by water inlet and outlet tubes. A cathode is in a cathode chamber at the end of the discharge tube closest to the light emitting surface; a spiral gas return tube communicates with the cathode chamber; an anode circumscribes the outside of the water cooling tube at the other end of the discharge tube. The positive high-voltage laser can increase power with a limited length.

The present disclosure provides a dark cavity laser, including: a frequency stabilized laser output device configured to generate a laser light, and perform a frequency stabilized processing on the generated laser light to output it to the dark cavity laser device as a pump light of a gain medium of a dark cavity; and a dark cavity laser device including a main cavity, and a cavity of the main cavity is provided inside with a gas chamber of a gain medium of a dark cavity laser light, where the gain medium of the dark cavity laser light is alkali metal atoms; the dark cavity laser device is configured to receive the pump light, and form a polyatomic coherent stimulated radiation between transition levels of the alkali metal atoms in the gas chamber by a weak feedback of the main cavity to generate the dark cavity laser light.

The present disclosure provides a dark cavity laser, including: a frequency stabilized laser output device configured to generate a laser light, and perform a frequency stabilized processing on the generated laser light to output it to the dark cavity laser device as a pump light of a gain medium of a dark cavity; and a dark cavity laser device including a main cavity, and a cavity of the main cavity is provided inside with a gas chamber of a gain medium of a dark cavity laser light, where the gain medium of the dark cavity laser light is alkali metal atoms; the dark cavity laser device is configured to receive the pump light, and form a polyatomic coherent stimulated radiation between transition levels of the alkali metal atoms in the gas chamber by a weak feedback of the main cavity to generate the dark cavity laser light.

The disclosure relates to a cancer treatment system including: a radiation source configured to produce 1.27-micrometer wavelength radiation, wherein the 1.27-micrometer wavelength radiation is generated from singlet oxygen. The radiation source may be an oxygen laser or an amplified spontaneous emission generator. The 1.27-micrometer wavelength radiation may be a laser or an amplified spontaneous emission.

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.

A radio-frequency excited carbon dioxide (CO.sub.2) or carbon monoxide (CO) gas laser includes two electrodes, which have passivated surfaces, within a sealed housing. Features in a ceramic slab or a ceramic cylinder located between the electrodes define a gain volume. Surfaces of the ceramic slab or the ceramic cylinder are separated from the passivated surfaces of the electrodes by small gaps to prevent abrasion thereof. Reducing compressive forces that secure these components within the housing further reduces abrasion, thereby extending the operational lifetime of the gas laser.

A compact laser system with a folded annular resonator cavity defined by spherical mirrors (17, 18), enabling the generation of a multipass beam path between the mirrors, each beam pass inclined at a small angle to the axis between the mirrors to form a zig-zag path (28, 29) therebetween. A long optical path is achieved within a short physical structure. The optical resonator cavity is confined in the gap between two cylindrical coaxial electrodes (13, 14) receiving RF power to excite the lasing gas. Apertures (23) are provided in the main cavity mirrors (17, 18), with a high reflectivity end mirror (24) behind one aperture at one end and a partially reflective output coupler (25) at the other end. A channeled ceramic cylindrical element (15, 20) within the annular shaped gap between the two cylindrical electrodes confines the lasing gas to the channels (16).

A radio-frequency, RF, slab laser 10 with a Z-fold resonator cavity defined by an output mirror 32, a first fold mirror 34, a second fold mirror 36 and a rear mirror 30. The second fold mirror 36 is rotated by an adjustment angle away from the angle it would have if the mirrors were all plane mirrors and directed the round trip beam path by direct reflection. Moreover, the rear mirror 30 is rotated by an adjustment angle that is approximately twice the adjustment angle of the second fold mirror 36. These rotations of the rear mirror 30 and second fold mirror 36 suppresses parasitic mode paths that would otherwise exist.

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.

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.