Abstract: An optical instrument for light incoming along a principal optical axis includes a glass block and a subsurface object within the glass block. The subsurface object includes an arrangement of object marks. Each object mark includes a plurality of scattering layers stacked against the principal optical axis of the incoming light. First and second scattering layers of the plurality of scattering layers have different polarization responses.

Abstract: An optical instrument for light incoming along a principal optical axis includes a glass block and a subsurface object within the glass block. The subsurface object includes an arrangement of object marks. Each object mark includes a plurality of scattering layers stacked against the principal optical axis of the incoming light. First and second scattering layers of the plurality of scattering layers have different polarization responses.

Abstract: An optical instrument for light incoming along a principal optical axis includes a glass block and a subsurface object within the glass block. The subsurface object includes an arrangement of object marks. Each object mark includes a plurality of scattering layers stacked against the principal optical axis of the incoming light. First and second scattering layers of the plurality of scattering layers have different polarization responses.

Abstract: A laser includes a gain stage and a pump stage. The gain stage includes a fiber link that terminates at a pair of ends and includes a doped fiber. The pump stage includes a glass volume, the glass volume having a pair of fiber interface ports at which the pair of ends of the fiber link are disposed, respectively, for attachment of the gain stage and the pump stage in a ring laser assembly. The pump stage includes a plurality of intrinsic waveguides defined in the glass volume and disposed along in-bulk propagation paths within the glass volume for light travel through the ring laser assembly.

Abstract: A method continuously monitors variations in the size of particles present in a fluid on a real time basis. The method includes passing one or more optical signal through the fluid such as engine oil. The variation (attenuation or enhancement) in the intensity of the optical signal is continuously measured with respect to time. In an embodiment, the method enables monitoring of the amount, size and onset of particle agglomeration using single or multiple wavelengths as interrogating optical signal(s). An exemplary embodiment is provided for monitoring of the amount, size and onset of soot particle agglomeration in engine oil using single or multiple wavelengths as interrogating optical signal(s).

Abstract: A method of writing a waveguide using an ultrashort laser beam is disclosed. The laser beam is directed to a substrate in transverse relation to a waveguide propagation axis to generate an ultrashort laser pulse focus in the substrate. A refractive index is modified in an affected region in the substrate along the waveguide propagation axis via the ultrashort laser pulse focus, and the ultrashort laser pulse focus is moved in a direction other than the waveguide propagation axis to generate a widened affected region along the waveguide propagation axis. The widened affected region has a cross-sectional profile capable of supporting a fundamental mode of a signal having a telecommunications infrared (TIR) wavelength, while the affected region has a cross-sectional profile incapable of supporting the fundamental mode of the signal having the TIR wavelength.

Abstract: Disclosed herein are an optical device, such as a connector or mode enlarger, and a method of fabricating the device. The disclosed device includes an optical medium having a first face for, e.g., permanent attachment to a waveguide, a second face for, e.g., a non-permanent connection, and a region between the first and second faces. A non-fiber, connector waveguide is disposed in the region to propagate the single-mode signal from the first face to the second face. The connector waveguide is optically matched to the waveguide at the first face to receive the single-mode signal carried by the waveguide. The connector waveguide includes a taper section such that the connector waveguide is enlarged at the second face to support an expanded beam of the single-mode signal for propagation through the non-permanent connection.

Abstract: A method of writing a waveguide using an ultrashort laser beam is disclosed. The laser beam is directed to a substrate in transverse relation to a waveguide propagation axis to generate an ultrashort laser pulse focus in the substrate. A refractive index is modified in an affected region in the substrate along the waveguide propagation axis via the ultrashort laser pulse focus, and the ultrashort laser pulse focus is moved in a direction other than the waveguide propagation axis to generate a widened affected region along the waveguide propagation axis. The widened affected region has a cross-sectional profile capable of supporting a fundamental mode of a signal having a telecommunications infrared (TIR) wavelength, while the affected region has a cross-sectional profile incapable of supporting the fundamental mode of the signal having the TIR wavelength.

Abstract: A monolithic device for determining a translation, the monolithic device being fabricated from a single continuous piece of a glass substrate. The monolithic device comprises at least one frame, a moving platform linked to the at least one frame and an optical transducer. The at least one frame is fabricated from the glass substrate. The moving platform is fabricated from the glass substrate, wherein the moving platform is linked to the at least one frame via at least one elastic hinge. The at least one elastic hinge is also fabricated from the glass substrate. The optical transducer is imbedded into the moving platform and the at least one frame.

Abstract: A method and apparatus for manufacturing a fuel injector comprising a glass substrate and a nozzle enclosed within the glass substrate, wherein the nozzle comprises at least one injection hole is provided. The method of manufacturing the fuel injector comprises defining (105) a shape of at least one injection hole in a glass substrate to obtain an at least one outlined injection hole and etching (110) the at least one outlined injection hole to obtain the at least one injection hole.

Abstract: Disclosed herein is a system useful for machining a workpiece, and having a first light source to generate a first beam for application to a first portion of the workpiece and ablation thereof, a second light source to generate a second beam for application to a second portion of the workpiece and heating thereof, and a positioning apparatus to direct the first and second beams to the first and second portions of the workpiece, respectively. The first light source may include a machining laser, and the second light source include a softening laser. A method of machining the workpiece includes the steps of removing a first portion of the workpiece by directing the first beam to the workpiece wherein the first beam has an intensity sufficient to ablate material from the workpiece, and heating a second portion of the workpiece to a ductile state by directing the second beam to the workpiece.

Abstract: A method of using a beam of ultra-short laser pulses, having pulse durations below 10 picoseconds, to adjust an optical characteristic within an optical medium is provided. The beams would have an intensity above a threshold for altering the index of refraction of a portion of the optical medium. The beams could be selectively applied to the optical medium and any structures formed or existing therein. Thus, the beam could be moved within a waveguide in the optical medium to alter the index of refraction of the waveguide forming any number of different longitudinal index of refraction profiles. The beam could also be moved within the optical medium near the waveguide to alter an effective index of refraction of a signal traveling within the waveguide. The techniques described can be used to improve, alter or correct performance of waveguide-based optical devices, such as arrayed waveguide gratings and cascaded planar waveguide interferometers.

Abstract: Ultrafast pulse beams of light are used to direct-write three-dimensional index profiles in materials using the unique material changing capabilities of ultra-short (i.e. <10 picosecond) laser pulses. An existing waveguide or waveguide circuit fabricated by some technique (for example but not limited to photolithography, flame hydrolysis deposition, modified chemical vapor deposition, or ultra-fast laser pulse direct writing) is modified by altering the index of refraction (index trimming) in a localized region or different local regions of the waveguide structure. Index trimming is accomplished through the action of a focused laser beam (or multiple focused beams) consisting of one or more ultra-short laser pulses and is generally performed at a wavelength in which the material is transparent or weakly absorbing, to the fundamental wavelength of the beam of light. The trimmed index pattern is generated by, but not limited to, moving the focal position of the beam or by moving the sample (i.e.

Abstract: A method of using a beam of ultra-short laser pulses, having pulse durations below 10 picoseconds, to adjust an optical characteristic within an optical medium is provided. The beams would have an intensity above a threshold for altering the index of refraction of a portion of the optical medium. The beams could be selectively applied to the optical medium and any structures formed or existing therein. Thus, the beam could be moved within a waveguide in the optical medium to alter the index of refraction of the waveguide forming any number of different longitudinal index of refraction profiles. The beam could also be moved within the optical medium near the waveguide to alter an effective index of refraction of a signal traveling within the waveguide. The techniques described can be used to improve, alter or correct performance of waveguide-based optical devices, such as arrayed waveguide gratings and cascaded planar waveguide interferometers.

Abstract: Ultrafast pulse beams of light are used to direct-write three-dimensional index profiles in materials using the unique material changing capabilities of ultra-short (i.e. <10 picosecond) laser pulses. An existing waveguide or waveguide circuit fabricated by some technique (for example but not limited to photolithography, flame hydrolysis deposition, modified chemical vapor deposition, or ultra-fast laser pulse direct writing) is modified by altering the index of refraction (index trimming) in a localized region or different local regions of the waveguide structure. Index trimming is accomplished through the action of a focused laser beam (or multiple focused beams) consisting of one or more ultra-short laser pulses and is generally performed at a wavelength in which the material is transparent or weakly absorbing, to the fundamental wavelength of the beam of light. The trimmed index pattern is generated by, but not limited to, moving the focal position of the beam or by moving the sample (i.e.