Abstract: Disclosed are methods and apparatus for hermetically sealing a nonlinear optical (NLO) crystal for use in a laser system. A mounted NLO crystal, an enclosure base, a lid, and a plurality of window components are moved into an oven. A vacuum bake process is then performed on the mounted NLO crystal, enclosure base, lid, and plurality of window components until a humidity level that is less than a predefined amount is reached. The mounted NLO crystal, enclosure base, lid, and plurality of window components are moved from the oven onto a stage of a glove box that includes a sealing tool. In the glove box, the mounted NLO crystal is hermetically sealed into the enclosure base by sealing the lid and plurality of window components into openings of the enclosure base.

Abstract: Disclosed are methods and apparatus for hermetically sealing a nonlinear optical (NLO) crystal for use in a laser system. A mounted NLO crystal, an enclosure base, a lid, and a plurality of window components are moved into an oven. A vacuum bake process is then performed on the mounted NLO crystal, enclosure base, lid, and plurality of window components until a humidity level that is less than a predefined amount is reached. The mounted NLO crystal, enclosure base, lid, and plurality of window components are moved from the oven onto a stage of a glove box that includes a sealing tool. In the glove box, the mounted NLO crystal is hermetically sealed into the enclosure base by sealing the lid and plurality of window components into openings of the enclosure base.

Abstract: A method of scanning a sample includes simultaneously forming a plurality of co-linear scans. Each scan is formed by a sweep of a spot by an acousto-optical device (AOD). The co-linear scans are separated by a predetermined spacing. A first plurality of swaths are formed by repeating the simultaneous forming of the plurality of co-linear scans in a direction perpendicular to the co-linear scans. The first plurality of swaths have an inter-swath spacing that is the same as the predetermined spacing. The predetermined spacing can be a scan length or an integral number of scan lengths. A second plurality of swaths can be formed adjacent to the first plurality of swaths. Forming the second plurality of swaths can be performed in an opposite direction to that of the first plurality of swaths or in a same direction. An inspection system can implement this method by including a diffractive optical element (DOE) path after a magnification changer.

Abstract: A system to generate multiple beam lines in an oblique angle multi-beam spot scanning wafer inspection system includes a beam scanning device configured to scan a beam of illumination, an objective lens oriented at an oblique angle relative to the surface of a sample and with an optical axis perpendicular to a first scanning direction on the sample, and one or more optical elements positioned between the objective lens and the beam scanning device. The one or more optical elements split the beam into two or more offset beams such that the two or more offset beams are separated in a least a second direction perpendicular to the first direction. The one or more optical elements further modify the phase characteristics of the two or more offset beams such that the two or more offset beams are simultaneously in focus on the sample during a scan.

Abstract: A system to generate multiple beam lines in an oblique angle multi-beam spot scanning wafer inspection system includes a beam scanning device configured to scan a beam of illumination, an objective lens oriented at an oblique angle relative to the surface of a sample and with an optical axis perpendicular to a first scanning direction on the sample, and one or more optical elements positioned between the objective lens and the beam scanning device. The one or more optical elements split the beam into two or more offset beams such that the two or more offset beams are separated in a least a second direction perpendicular to the first direction. The one or more optical elements further modify the phase characteristics of the two or more offset beams such that the two or more offset beams are simultaneously in focus on the sample during a scan.

Abstract: A method of scanning a sample includes simultaneously forming a plurality of co-linear scans. Each scan is formed by a sweep of a spot by an acousto-optical device (AOD). The co-linear scans are separated by a predetermined spacing. A first plurality of swaths are formed by repeating the simultaneous forming of the plurality of co-linear scans in a direction perpendicular to the co-linear scans. The first plurality of swaths have an inter-swath spacing that is the same as the predetermined spacing. The predetermined spacing can be a scan length or an integral number of scan lengths. A second plurality of swaths can be formed adjacent to the first plurality of swaths. Forming the second plurality of swaths can be performed in an opposite direction to that of the first plurality of swaths or in a same direction. An inspection system can implement this method by including a diffractive optical element (DOE) path after a magnification changer.

Abstract: One embodiment relates to an oblique illuminator. The oblique illuminator includes a light source emitting a light beam, a first reflective surface, and a second reflective surface. The first reflective surface has a convex cylindrical shape with a projected parabolic profile along the non-powered direction which is configured to reflect the light beam from the light source and which defines a focal line. The second reflective surface has a concave cylindrical shape with a projected elliptical profile which is configured to reflect the light beam from the first reflective surface and which defines first and second focal lines. The focal line of the first reflective surface is coincident with the first focal line of the second reflective surface. The first and second focal lines of the second reflective surface may be a same line in which case the elliptical curvature is a projected spherical profile. Other embodiments, aspects and features are also disclosed.

Abstract: A method of scanning a sample includes simultaneously forming a plurality of co-linear scans. Each scan is formed by a sweep of a spot by an acousto-optical device (AOD). The co-linear scans are separated by a predetermined spacing. A first plurality of swaths are formed by repeating the simultaneous forming of the plurality of co-linear scans in a direction perpendicular to the co-linear scans. The first plurality of swaths have an inter-swath spacing that is the same as the predetermined spacing. A second plurality of swaths can be formed adjacent to the first plurality of swaths. Forming the second plurality of swaths can be performed in an opposite direction to that of the first plurality of swaths or in a same direction. An inspection system can implement this method by including a diffractive optical element (DOE) path after a magnification changer.

Abstract: One embodiment relates to an oblique illuminator. The oblique illuminator includes a light source emitting a light beam, a first reflective surface, and a second reflective surface. The first reflective surface has a convex cylindrical shape with a projected parabolic profile along the non-powered direction which is configured to reflect the light beam from the light source and which defines a focal line. The second reflective surface has a concave cylindrical shape with a projected elliptical profile which is configured to reflect the light beam from the first reflective surface and which defines first and second focal lines. The focal line of the first reflective surface is coincident with the first focal line of the second reflective surface. The first and second focal lines of the second reflective surface may be a same line in which case the elliptical curvature is a projected spherical profile. Other embodiments, aspects and features are also disclosed.

Abstract: One embodiment relates to an oblique illuminator. The oblique illuminator includes a light source emitting a light beam, a first reflective surface, and a second reflective surface. The first reflective surface has a convex cylindrical shape with a projected parabolic profile along the non-powered direction which is configured to reflect the light beam from the light source and which defines a focal line. The second reflective surface has a concave cylindrical shape with a projected elliptical profile which is configured to reflect the light beam from the first reflective surface and which defines first and second focal lines. The focal line of the first reflective surface is coincident with the first focal line of the second reflective surface. The first and second focal lines of the second reflective surface may be a same line in which case the elliptical curvature is a projected spherical profile. Other embodiments, aspects and features are also disclosed.

Abstract: One embodiment relates to an oblique illuminator. The oblique illuminator includes a light source emitting a light beam, a first reflective surface, and a second reflective surface. The first reflective surface has a convex cylindrical shape with a projected parabolic profile along the non-powered direction which is configured to reflect the light beam from the light source and which defines a focal line. The second reflective surface has a concave cylindrical shape with a projected elliptical profile which is configured to reflect the light beam from the first reflective surface and which defines first and second focal lines. The focal line of the first reflective surface is coincident with the first focal line of the second reflective surface. The first and second focal lines of the second reflective surface may be a same line in which case the elliptical curvature is a projected spherical profile. Other embodiments, aspects and features are also disclosed.

Abstract: A method and apparatus is described for controlling the attenuation of multiple wavelengths signals propagating in an optical fiber, that may have a time-dependent power in each signal, to provide an output signal having a desired attenuated power in each of the multiple signals. An equalizer may be used that has various optical elements to focus and disperse light, such as a concave diffraction grating and a modulator array having modulators disposed on a concave surface. The equalizer may also be coupled to various components such as a circulator or thermally expanded core fibers.

Abstract: An optical channel monitoring device uses a linear variable filter (LVF) disposed in the path of a beam of light for selectively transmitting light in a variable manner along a length of the filter, a photodetector array positioned in the path of light transmitted through the LVF for measuring spectral characteristics of the transmitted light, and collimating means disposed between the input port and the LVF for collimating said beam of light. The device is a low-cost, compact and rugged high-resolution spectrometer for various uses.

Abstract: An optical channel monitoring device uses a linear variable filter (LVF) disposed in the path of a beam of light for selectively transmitting light in a variable manner along a length of the filter, a photodetector array positioned in the path of light transmitted through the LVF for measuring spectral characteristics of the transmitted light, and collimating means disposed between the input port and the LVF for collimating said beam of light. The device is a low-cost, compact and rugged high-resolution spectrometer for various uses.

Abstract: A dynamic gain flattening filter is provided that offers a smooth spectral response. The filter includes an input/output port for launching a beam of light, a dispersive element for dispersing the beam of light into a plurality of monochromatic sub-beams of light, and discrete array of controllable elements for receiving the plurality of sub-beams of light. The filter is designed such that each sub-beam of light is incident on more than one element of the discrete array for selective attenuation before being recombined by the dispersive element and redirected back to the input/output port. In another embodiment, a beam-folding mirror is provided to direct the attenuated beam to a separate output port.

Abstract: A method and apparatus is described for controlling the attenuation of multiple wavelengths signals propagating in an optical fiber, that may have a time-dependent power in each signal, to provide an output signal having a desired attenuated power in each of the multiple signals. An equalizer may be used that has various optical elements to focus and disperse light, such as a concave diffraction grating and a modulator array having modulators disposed on a concave surface. The equalizer may also be coupled to various components such as a circulator or thermally expanded core fibers.

Abstract: A dynamic gain flattening filter is provided that offers a smooth spectral response. The filter includes an input/output port for launching a beam of light, a dispersive element for dispersing the beam of light into a plurality of monochromatic sub-beams of light, and discrete array of controllable elements for receiving the plurality of sub-beams of light. The filter is designed such that each sub-beam of light is incident on more than one element of the discrete array for selective attenuation before being recombined by the dispersive element and redirected back to the input/output port. In another embodiment, a beam-folding mirror is provided to direct the attenuated beam to a separate output port.