3 results about "Quadratic phase" patented technology

The present application relates to a kind of Hartmann wavefront measurement dynamic range extension method based on quadratic phase control, belong to wavefront measurement technical field.For the problem that the measurable slope interval is limited in the limited detection displacement range in traditional Hartmann wavefront measurement, at least the sub-aperture phase distribution containing reference focusing phase and quadratic phase term is constructed in super surface phase control, and the displacement of each sub-aperture corresponding light spot on the detection surface and the local average slope of the sub-aperture satisfy the preset monotone reversible nonlinear mapping relationship in design working interval by combining theoretical modeling, numerical optimization and / or experimental calibration.The present application can reconstruct the slope-displacement encoding rule of traditional Hartmann under the premise of keeping local average slope reversible and wavefront reconstructable, extend the encodable slope range in given displacement range, so as to improve the dynamic range of Hartmann wavefront measurement, especially suitable for the measurement scene of strong non-uniform, large dynamic range wavefront.

This invention discloses a robust detection method and system for high-speed, highly maneuverable targets based on Radon-LVD transform, belonging to the field of radar signal processing. The method estimates the target's velocity and acceleration from the pulse-compressed echo signal using Radon-LVD transform; constructs a slow-time-range frequency domain quadratic phase compensation function using the velocity and acceleration estimates; performs migration compensation on the slow-time-range frequency domain of the echo signal; and then performs moving target detection in the range-Doppler domain. The two searches during this process improve the accuracy of target parameter estimation. This invention combines Radon transform and LVD transform, which can compensate for range migration and Doppler migration respectively, achieving coherent accumulation of energy in the echo signal of a uniformly accelerated target.

This invention belongs to the field of laser shaping technology and provides a three-channel parallel ultrafast laser shaping system and method based on spatiotemporal compensation. By setting a pre-dispersion compensation module, this invention introduces controlled negative dispersion in advance, thereby precisely offsetting the pulse broadening induced by digital micromirror array diffraction and thick glass elements in subsequent branches, ensuring that the pulse width of each shaping branch at the focal plane remains in a fidelity state. The beam is distributed to three functionally complementary shaping branches, and a digital virtual focal length is generated by superimposing a specific quadratic phase function. This allows for dynamic compensation of focal position deviations between branches without moving any mechanical components, achieving instantaneous drift-free alignment of multimodal coaxial focal points. This invention not only achieves multi-dimensional flexible customization of the processed morphology but also ensures high consistency of processing thresholds and high fidelity of spatiotemporal pulses during high-speed switching of modes.