Abstract: A construction method and system for asset value models in a digital twin engine includes: measuring the level of business importance based on a business model of building energy consumption assets, and constructing a first asset value model according to the business importance; establishing a correlation between the assets and productivity, and constructing a second asset value model according to productivity loss caused by the assets; and calculating the energy use efficiency of a building according to optimal decision variables, predicting the degradation index of the assets through the energy use efficiency, the first asset value model and the second asset value model, and generating a maintenance solution of the assets. The disclosed has ingenious conception and excellent effect, and realizes the accurate evaluation of the asset value by establishing the correlation between the assets and different businesses and different efficiency, generating the optimal and most accurate asset maintenance solution.

Abstract: Chirped pulse amplification (CPA) systems configured to generate and amplify multi-pulses are described. The nonlinear interaction of pulses can generate a multiple pulse pack with a dense time separation between pulses. Reducing or eliminating the nonlinear interaction can be provided by spectrally and/or temporally splitting pulses in the chirped amplification system.

Abstract: Chirped pulse amplification (CPA) systems configured to generate and amplify multi-pulses are described. The nonlinear interaction of pulses can generate a multiple pulse pack with a dense time separation between pulses. Reducing or eliminating the nonlinear interaction can be provided by spectrally and/or temporally splitting pulses in the chirped amplification system.

Abstract: A current sensorless control system and a control method thereof for single stage isolated PFC converters based on DAB. By coordinating three control variables of the DAB converter, that is, the inside phase-shifting ratio of the primary side full-bridge, the inside phase-shifting ratio of the secondary side full-bridge, and the phase-shifting ratio between the primary and the secondary sides, the present invention does not need to design additional current controller for the control of the input current, and may make the input current sinusoidal by directly coordinating the output voltage controller, the input voltage and the current modulation step, thereby reducing system cost and the difficulty of controller design, enhancing the stability of the control system, and improving the dynamic performance.

Abstract: In at least one embodiment a laser system includes a fiber laser source, a polarization controller and a wavelength converter. The relative power distribution between a pump wavelength and a signal wavelength is controllable using the polarization controller. An optional phase compensator is used to control polarization state of the output laser beam. In various embodiments the relative power distribution among multiple wavelengths may be controlled over a range of at least about 100:1.

Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse width sufficiently short so that material is efficiently removed by nonlinear optical absorption from the region and a quantity of heat affected zone and thermal stress on the material within the region, proximate to the region, or both is reduced relative to a quantity obtainable using a laser with longer pulses. In at least one embodiment, an ultrashort pulse laser system may include at least one of a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a composite material.

Abstract: In at least one embodiment time separated pulse pairs are generated, followed by amplification to increase the available peak and/or average power. The pulses are characterized by a time separation that exceeds the input pulse width and with distinct polarization states. The time and polarization discrimination allows easy extraction of the pulses after amplification. In some embodiments polarization maintaining (PM) fibers and/or amplifiers are utilized which provides a compact arrangement. At least one implementation provides for seeding of a solid state amplifier or large core fiber amplifier with time delayed, polarization split pulses, with capability for recombining the time separated pulses at an amplifier output. In various implementations suitable combinations of bulk optics and fibers may be utilized. In some implementations wavelength converted pulse trains are generated.

Abstract: Methods, devices, and systems for ultrashort pulse laser processing of optically transparent materials are disclosed, with example applications in scribing, marking, welding, and joining. For example, ultrashort laser pulses create scribe features with one pass of the laser beam across the material, with at least one of the scribe features being formed below the surface of the material. Slightly modifying the ultrashort pulse laser processing conditions produces sub-surface marks. When properly arranged, these marks are clearly visible with correctly aligned illumination. Reflective marks may also be formed with control of laser parameters. A transparent material other than glass may be utilized. A method for welding transparent materials uses ultrashort laser pulses to create a bond through localized heating.

Abstract: In at least one embodiment time separated pulse pairs are generated, followed by amplification to increase the available peak and/or average power. The pulses are characterized by a time separation that exceeds the input pulse width and with distinct polarization states. The time and polarization discrimination allows easy extraction of the pulses after amplification. In some embodiments polarization maintaining (PM) fibers and/or amplifiers are utilized which provides a compact arrangement. At least one implementation provides for seeding of a solid state amplifier or large core fiber amplifier with time delayed, polarization split pulses, with capability for recombining the time separated pulses at an amplifier output. In various implementations suitable combinations of bulk optics and fibers may be utilized. In some implementations wavelength converted pulse trains are generated.

Abstract: Methods, devices, and systems for ultrashort pulse laser processing of optically transparent materials are presented, with example applications in scribing, marking, welding, and joining. For example, ultrashort laser pulses create multiple scribe features with one pass of the laser beam across the material, with at least one of the scribe features being formed below the surface of the material. Slightly modifying the ultrashort pulse laser processing conditions produces different types of sub-surface marks. When properly arranged, these marks are clearly visible with correctly aligned illumination through either light scattering or light reflection and nearly invisible without illumination. Transparent material other than glass may be utilized. A method for welding transparent materials uses ultrashort laser pulses to create a bond through localized heating.

Abstract: In at least one embodiment a laser system includes a fiber laser source, a polarization controller and a wavelength converter. The relative power distribution between a pump wavelength and a signal wavelength is controllable using the polarization controller. An optional phase compensator is used to control polarization state of the output laser beam. In various embodiments the relative power distribution among multiple wavelengths may be controlled over a range of at least about 100:1.

Abstract: Examples of methods and systems for laser processing of materials are disclosed. Methods and systems for singulation of a wafer comprising a coated substrate can utilize a laser outputting light that has a wavelength that is transparent to the wafer substrate but which may not be transparent to the coating layer(s). Using techniques for managing fluence and focal condition of the laser beam, the coating layer(s) and the substrate material can be processed through ablation and internal modification, respectively. The internal modification can result in die separation.

Abstract: In at least one embodiment a laser system includes a fiber laser source, a polarization controller and a wavelength converter. The relative power distribution between a pump wavelength and a signal wavelength is controllable using the polarization controller. An optional phase compensator is used to control polarization state of the output laser beam. In various embodiments the relative power distribution among multiple wavelengths may be controlled over a range of at least about 100:1.

Abstract: Examples of methods and systems for laser processing of materials are disclosed. Methods and systems for singulation of a wafer comprising a coated substrate can utilize a laser outputting light that has a wavelength that is transparent to the wafer substrate but which may not be transparent to the coating layer(s). Using techniques for managing fluence and focal condition of the laser beam, the coating layer(s) and the substrate material can be processed through ablation and internal modification, respectively. The internal modification can result in die separation.

Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. Embodiments of an ultrashort pulse laser system may include a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond, picosecond, and/or nanosecond pulses.

Abstract: Methods and apparatus for detecting variations in electromagnetic fields, in particular, terahertz (THz) electromagnetic fields, are provided. The methods and apparatus employ polarization detection devices and controllers to maintain or vary the polarization of modulated signals as desired. The methods and apparatus are provided to characterize electromagnetic fields by directing the electromagnetic field and a probe beam upon an electro-crystal and detecting the modulation of the resulting probe beam. Detection of the modulation of the probe beam is practiced by detecting and comparing the polarization components of the modulated probe beam. Aspects of the invention may be used to analyze or detect explosives, explosive related compounds, and pharmaceuticals, among other substances. A compact apparatus, modular optical devices for use with the apparatus, sample holders, and radiation source mounts are also disclosed.

Abstract: Methods and systems for delivery of high peak power optical pulses through optical fiber are disclosed. Raman soliton generation is utilized to maintain the properties of the pulses in the delivery fiber. The apparatus can comprise any high peak power pulse source and delivery fiber supporting Raman soliton generation.

Abstract: Methods and apparatus for detecting variations in electromagnetic fields, in particular, terahertz (THz) electromagnetic fields, are provided. The methods and apparatus employ polarization detection devices and controllers to maintain or vary the polarization of modulated signals as desired. The methods and apparatus are provided to characterize electromagnetic fields by directing the electromagnetic field and a probe beam upon an electro-crystal and detecting the modulation of the resulting probe beam. Detection of the modulation of the probe beam is practiced by detecting and comparing the polarization components of the modulated probe beam. Aspects of the invention may be used to analyze or detect explosives, explosive related compounds, and pharmaceuticals, among other substances. A compact apparatus, modular optical devices for use with the apparatus, sample holders, and radiation source mounts are also disclosed.

Abstract: Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. Embodiments of an ultrashort pulse laser system may include a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond, picosecond, and/or nanosecond pulses.

Abstract: A method of forming patterns on transparent substrates using a pulsed laser is disclosed. Various embodiments include an ultrashort pulsed laser, a substrate that is transparent to the laser wavelength, and a target plate. The laser beam is guided through the transparent substrate and focused on the target surface. The target material is ablated by the laser and is deposited on the opposite substrate surface. A pattern, for example a gray scale image, is formed by scanning the laser beam relative to the target. Variations of the laser beam scan speed and scan line density control the material deposition and change the optical properties of the deposited patterns, creating a visual effect of gray scale. In some embodiments patterns may be formed on a portion of a microelectronic device during a fabrication process. In some embodiments high repetition rate picoseconds and nanosecond sources are configured to produce the patterns.