50results about How to "Improve optical precision" patented technology

Provided is a method for enhancing accuracy of an optical metrology system that includes a metrology tool, an optical metrology model, and a profile extraction algorithm. The optical metrology model includes a model of the metrology tool and a profile model of the sample structure, the profile model having profile parameters. A library comprising Jones and / or Mueller matrices and / or components (JMMOC) and corresponding profile parameters is generated using ray tracing and a selected range of beam propagation parameters. An original simulated diffraction signal is calculated using the optical metrology model. A regenerated simulated diffraction signal is obtained using the regenerated JMMOC, integrated for all the rays of the optical metrology model. If an error and precision criteria for the regenerated simulated diffraction signal compared to the original simulated diffraction signal are met, one or more profile parameters are determined from the best match regenerated simulated diffraction signal.

A press molding apparatus includes upper and lower mother molds 102 and 104. Each of the mother molds 102 and 104 has four molding surfaces arranged in a single line and satisfies the relationship given by L×α×ΔT / t<0.0008, where L represents the length, t, the thickness, α, the thermal expansion coefficient, and ΔT, the temperature difference between both ends in the thickness direction during induction heating. The press molding apparatus may include a pressing mold set including upper mother molds 102a and 102b attached to a common fixed shaft 118 through upper supporting shafts 110a and 110b and lower mother molds 104a and 104b driven by a common drive shaft 120 through lower supporting shafts 112a and 112b. The upper mother molds 102a and 102b and the lower mother molds 104a and 104b are collectively heated by induction heating coils 122 and 124, respectively.

The invention discloses a high-precision photodynamic accelerometer based on a zipper type photonic crystal micro-nano cavity. The accelerometer comprises a laser input and reception structure arranged in the left and right sides of the accelerometer structure, a silicon micro mechanical structure arranged in the middle portion of the accelerometer, and a glass substrate structure positioned in the bottom of the silicon micro mechanical structure and provided with electrodes. A laser incident structure is arranged in an input groove in the left side of a main silicon microstructure, a reception structure is arranged in an output groove in the right side of the main silicon microstructure. An optical signal serves as a measurement signal of the micro accelerometer, the sensitivity is high,the uncertainty is low, the detection limit of the micro accelerometer is improved, and the detection sensitivity is improved greatly. The zipper type photonic crystal micro-nano cavity is used, the performance is more stable and the optical precision is higher compared with a common planar parallel resonance micro-nano cavity at present, and higher acceleration sensitivity is achieved.

The invention discloses a free-form optical reflector for an LED (light-emitting diode) motorcycle low beam, wherein an internal surface of the reflector is a free-form surface to form an optical reflecting surface; the bottom surface of the reflector is provided with an opening for installation of an LED; one end rightly facing the bottom surface is a light exit port of the reflector; the majority of light emitted by the LED light source is reflected by the internal surface of the reflector and then is emergent to an illuminating plane, and the other light is directly emergent to the illuminating plane. The reflector is divided into an upper part and a lower part; the free-form surface at the upper part of the internal surface of the reflector is mainly used for reflecting the light above a horizontal plane to the illuminating plane below the horizontal plane; the free-form surface at the lower part of the internal surface of the reflector is mainly used for gathering diffused light below the horizontal plane to the illuminating plane below the horizontal plane. The free-form optical reflector for the LED motorcycle low beam has the characteristics of simple structure, convenience in installation and high utilization rate of light energy; light direction can be effectively controlled and the glare effect can be inhibited; and the free-form optical reflector for the LED motorcycle low beam meets the light distribution requirements in GB5948-1998.