4 results about "Nonlinear absorption" patented technology

The application relates to a method for enhancing the nonlinear optical performance of SnS2 nanosheets through electrostatic doping. First, SnS2 nanosheets are prepared on a fluorine-doped tin oxide (FTO) substrate by a chemical vapor deposition method, and then hydrogen ion intercalated SnS2-H + The electrostatic doping causes the band gap to shrink and a strong built-in electric field to be generated, so that the nonlinear optical performance of the material is enhanced. In addition, the saturated absorption response of the material enables the application to an optical neural network as a nonlinear activation function, and exhibits application potential in machine learning tasks. The SnS2-H + The application establishes a promising and convenient nonlinear optical material, and provides new insights for the design exploration and simple synthesis of high-performance nonlinear absorption materials.

This application provides a tunable optical pulse source chip, relating to the field of semiconductor optoelectronic integrated device technology. The optical pulse source chip includes: a gain region for generating and amplifying an optical signal; a pulse selection region for receiving an external periodic electrical signal to form a periodically switching switching window, through which the amplified optical signal passes or is blocked; and a saturable absorption region for nonlinearly absorbing the optical signal passing through the pulse selection region to achieve mode locking, thereby generating and outputting an optical pulse. The repetition frequency of the optical pulse is tunable by controlling the frequency of the periodic electrical signal. This application integrates the gain region, pulse selection region, and saturable absorption region monolithically, and uses a periodic electrical signal to control the switching window of the pulse selection region. The output optical pulse repetition frequency is independently controlled by the frequency of the external electrical signal, decoupling the repetition frequency from the cavity length, thus enabling a wide-range, continuously tunable pulse repetition frequency.

This invention provides a multiphysics-coupled molecular dynamics simulation method and system for femtosecond laser ablation, comprising: establishing an atomic model of a wide-bandgap semiconductor material and its corresponding electronic grid; inputting laser parameters and material parameters and initializing field variables; introducing a carrier concentration evolution equation and updating the laser intensity distribution within the material based on the Drude model; considering the bandgap energy consumption term of the valence band electron transition process under femtosecond laser irradiation, improving the laser heat source term in the electronic temperature equation, updating the electronic temperature, and then obtaining the atomic-scale behavioral evolution through energy exchange between the electronic system and the lattice system, and outputting the results. This invention introduces the nonlinear absorption of femtosecond laser ablation of wide-bandgap semiconductor materials into a dual-temperature model-molecular dynamics model coupling framework, realizing a unified coupled simulation of energy deposition, carrier evolution, transient optical response, and material removal behavior of wide-bandgap semiconductor materials under femtosecond laser irradiation.

This application provides an optical fiber coupling end for femtosecond laser transmission optical cables, including a substrate with an internal through-hole in the center of the substrate, a fiber fixing tube sleeved inside the internal through-hole, a front sleeve and a rear sleeve respectively at both ends of the substrate, the fiber fixing tube having a hollow inner cavity, the hollow inner cavity communicating with the interior of the front sleeve and the rear sleeve, one end of the rear sleeve being connected to the optical cable, the hollow fiber in the optical cable passing through the rear sleeve to extend into the hollow inner cavity, the end of the hollow inner cavity near the front sleeve having an optical fiber sleeve, the optical fiber sleeve fixing the hollow fiber end, an annular cavity between the internal through-hole and the fiber fixing tube, the substrate having a water inlet and a water outlet communicating with the annular cavity, which solves the problem of heat accumulation at the coupling end face of femtosecond laser transmission optical fibers, and allows for convenient structural optimization by using vacuum to solve problems such as nonlinear absorption and pulse width expansion of the laser.