An optical inspection system that utilizes sub-200 nm incident light beam to inspect a surface of an object for defects is described. The sub-200 nm incident light beam is generated by combining first light having a wavelength of about 1109 nm with second light having a wavelength of approximately 234 nm. An optical system includes optical components configured to direct the incident light beam to a surface of the object, and image relay optics are configured to collect and relay at least two channels of light to a sensor, where at least one channel includes light reflected from the object, and at least one channel includes light transmitted through the object. The sensor is configured to simultaneously detect both the reflected and transmitted light. A laser for generating the sub-200 nm incident light beam includes a fundamental laser, two or more harmonic generators, a frequency doubler and a two frequency mixing stages.

An improved solid-state laser for generating sub-200 nm light is described. This laser uses a fundamental wavelength between about 1030 nm and 1065 nm to generate the sub-200 nm light. The final frequency conversion stage of the laser creates the sub-200 nm light by mixing a wavelength of approximately 1109 nm with a wavelength of approximately 234 nm. By proper selection of non-linear media, such mixing can be achieved by nearly non-critical phase matching. This mixing results in high conversion efficiency, good stability, and high reliability.

A method of operating a q-switch RE,XAB laser includes: providing a pump bias current to a pump source, the pump source directed to an RE:XAB gain medium, the RE:XAB gain medium within a resonator cavity, where X is selected from Ca, Lu, Yb, Nd, Sm, Eu, Gd, Ga, Tb, Dy, Ho, Er, and where RE is selected from Lu, Y, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Pr, Tm, Cr, Ho, with a bias current level below a lasing threshold of the RE:XAB gain medium; providing a pump pulse to the gain medium, the pump pulse of the lasing threshold of the RE:XAB gain medium, the pump pulse causing the RE:XAB gain medium to emit a laser pulse; and reducing the pump bias current to at least below the gain medium lasing threshold, the combination of the pump bias, the pump pulse, and the pump reduction having a current profile.

An extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

A laser system includes a seed source optically coupled to an extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam from the seed source. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

A laser system includes a laser element, a pump source configured to input light to the laser element, a first cooling circuit and a second cooling circuit. The first cooling circuit includes a first pump configured to drive a first flow of cooling liquid through a first fluid pathway, a first primary heat exchanger configured to cool the first flow of cooling liquid, and a laser element heat exchanger configured to remove heat from the laser element using the first flow of cooling liquid. The second cooling circuit includes a second pump configured to drive a flow of cooling liquid through a second fluid pathway, a second primary heat exchanger configured to cool the second flow of cooling liquid, and a pump source heat exchanger configured to remove heat from the pump source using the first and second flows of cooling liquid.

The present application discloses a high-power single-frequency pulsed laser based on an injection locking technology, including a pump light supply device, a seed light supply device, a slave laser, a light detector and a servo control system. The servo control system receives a probe signal outputted by the light detector and controls the cavity length of the slave laser according to an error signal extracted from the probe signal. The light detector has the characteristic of saturation current, and after the probe light enters the light detector, the pulse current becomes saturated and the modulated seed current becomes unsaturated. According to the present application, a light detector with pulse saturation current characteristics is adopted to effectively avoid the problem that the error signal cannot be obtained and it is difficult to achieve injection locking.

A laser light-source apparatus includes: a seed light source; a fiber amplifier configured to amplify pulse light output from the seed light source based on gain switching; a solid state amplifier configured to further amplify the resultant pulse light; a nonlinear optical element configured to perform wavelength conversion on the pulse light output from the solid state amplifier; an optical switching element that is disposed between the fiber amplifier and the solid state amplifier and is configured to remove ASE noise; and a control unit. The control unit is configured to control the optical switching element in such a manner that propagation of light is permitted in an output period of the pulse light from the seed light source, and is stopped in a period other than the output period.

A slab laser and its method of use for high power applications including the manufacture of semiconductors and deposition of diamond and/or diamond-like-carbon layers, among other materials. A lamp driven slab design with a face-to-face beam propagation scheme and an end reflection that redirects the amplified radiation back out the same input surface is utilized. A side-to-side amplifier configuration permitting very high average and peak powers having scalability is also disclosed. Cavity filters adjacent to pump lamps convert the normally unusable UV portion of the pump lamp spectrum into light in the absorption band of the slab laser, thereby increasing the overall pump efficiency. The angle of the end reflecting surface is changed to cause the exit beam to be at a different angle than the inlet beam, thereby eliminating the costly need to separate the beams external to the laser with the subsequent loss of power.

An improved solid-state laser for generating sub-200 nm light is described. This laser uses a fundamental wavelength between about 1030 nm and 1065 nm to generate the sub-200 nm light. The final frequency conversion stage of the laser creates the sub-200 nm light by mixing a wavelength of approximately 1109 nm with a wavelength of approximately 234 nm. By proper selection of non-linear media, such mixing can be achieved by nearly non-critical phase matching. This mixing results in high conversion efficiency, good stability, and high reliability.